Suburban RV FURNACES SERVICE MANUAL
DD-17DSI • DD-17DSIW NT-12S/SE • NT-16S/SE • NT-20S/SE NT-24SP • NT-30SP • NT-34SP NT-40 P-30S/40 SF-20 • SF-25 • SF-30 • SF- 35 • SF-42 SF-20F • SF-25F • SF-30F • SF-35F • SF-42F SH-35 • SH-42 SH-35F • SH-42F SHD-2542 SFV-35 • SFV-42 SFV-35F • SFV-42F
SUBURBAN MANUFACTURING COMPANY 676 Broadway Street Dayton, Tennessee 37321 423-775-2131 Fax: 423-775-7015 www.rvcomfort.com
[email protected]
TABLE OF CONTENTS Page
G e n e r a l S e r v ic e In f o r m a t io n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 F u rna c e S pe c Sh e et . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 In s t a lla tio n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 V e n t A s s e m b ly Illu s tr a tio n s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 1 6 R e tu r n A ir Illu s t r a tio n s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 6 D u c tin g Illu s tr a tio n s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 7 In s t a lla tio n R e q u ir e m en en ts ( D D , N T a n d P M o d e l F u r n a c e s ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 8 In s t a lla tio n Re Re q u ir e m en en ts (S (S F , S H an an d SH SH DD- 2 5 4 2 M od od e l F u r n a c e s ) . . . . . . . . . . . . . . . . . . . . . . . . . . 1 9 In s t a lla tio n R e q u ir e m e n t ( S F V M o d e l F u r n a c e s ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 0 F u r n a c e S p e c if ic a tio n s ( D D , N T a n d P M o d e l F u r n a c e s ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1 F ur ur na na ce ce S p ec ec ifif ic at atio ns ns ( S F , S F V , S H , a nd nd S H DD- 2 54 54 2 M od od el el F ur ur n ac ac es es ) . . . . . . . . . . . . . . . . . . . . . . . 2 2 S e q u e n c e of of Op Op e r a tio n (T (T im e D e l a y R e la y E q u ip p e d Fu Fu r n a c e s ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 3 S eq eq ue ue nc nc e o f O p er er at atio n ( Fa Fa n C o nt ntr ol ol M o du du le le Bo Bo ar ar d ( 52 52 08 08 20 20 ) E qu qu ip ip pe pe d F ur ur na na ce ce s) s) . . . . . . . . . . . . . . . 2 4 S e q u e n c e of of Op Op e r a tio n (2 (2 4 VA VA C Fa F a n Co C o n tr o l M od od u le Bo Bo a r d (5 (5 2 0 9 4 7 ) . . . . . . . . . . . . . . . . . . . . . . . . . 2 5 S e q u e n c e o f O p e r a tio n ( S H D - 2 5 4 2 F u r a n c e ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 6 T ro ro ub ub le le Sh Sh oo oo tin g F lo lo w Ch C h a rt rt ( F ur ur n a ce ce s E q ui uip pe pe d wi w ith Ti T im e De De la la y Re Re la la y) y) . . . . . . . . . . . . . . . . . . . . . 2 7 T ro ro ub ub le le Sh Sh oo oo titin g F lo lo w C h ar ar t ( Fu Fu rn rn ac ac es es E qu qu ip ip pe pe d w it ith Fa Fa n C on on tr tr ol ol M o du du le le Bo Bo ar ar d) d) . . . . . . . . . . . . . . 2 8 Service Hints, Diagnosis and Corrective Measures f o r Su Su b u r b a n 24 24 - V o lt AC AC El E le c tr o n ic Ig Ig n itio n Fu Fu r n a c e s . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 9 - 3 0 W ir in g D ia g r a m s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 0 - 3 4 F u r n a c e R e m o v a l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 5 -3 6 S F , S H an an d S H DD- 2 5 4 2 E le c tr o d e G ap ap S p e c if ic a tio n s & P o s itio n in g . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 7 N T a n d P a r k M o d e l E le c tr o d e G ap ap S p e c if ic a tio n s & P o s itio n in g
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
M a in t e n a n c e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 9 C a u tio n s & S a f e ty In f o r m a tio n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B a c k C o v e r
NOTE: Our service technicians are available to assist you in making repairs or parts replacements from 8:00 a.m. to 5:00 p.m. Eastern Standard Time, Monday through Friday (except holidays), by calling 423-775-213 1 extension 7102. E-mail address: info1@ info1@ suburban mfg.com
2
GENERAL SERVICE INFORMATION Suburban DYNATRAIL furnaces installed in recreational vehicles are classified as Direct Vent Sealed Combustion Furnaces. A forced draft furnace utilizes a sealed combustion chamber which is vented to the outside atmosphere. The intake air for combu stion is also also taken from outdoors and is com pletely isolated from the room air. A motor is used to drive an impeller wheel to draw intake air into the chamber to support combustion and force the exhaust gases through the furnace cham ber to the outside atmos atmos phere. A second im peller wheel (driven by the same m otor yet totally totally isolated from the combustion air) is used to circulate room air across the furnace chamber where it is heated. The blower then forces the hot air into the living living area either through a du ct system or throug h a front grille on the furnace cabinet on direct discharge models. Suburban furnac es operate on 12-volt DC pow er which is supplied either by a 12-volt battery battery or a converter system. A r ec re ation ati on al v eh icle icl e fu rnac rn ac e th at is sp ec ific ally all y de sig ne d fo r “pa “ pa rk m od el” tra ilers ile rs op erate er ate s o n 120 1 20 vo lts AC . The T he se are designed and tested under the same standards as the 12-volt models. Suburban forced draft combustion furnaces used in recreational vehicles are designed for use with Propane gas. Alt ho ug h a few fe w recr re crea ea tiona tio na l vehic ve hic le fur na ce s are ar e ap pr ov ed for fo r us e with wit h na tur al ga s, on e sh ou ld ne ve r attem at tem pt to convert such a u nit to to natural gas unless the conversion is approved by the manufacturer of the furnace.
Gas Supply Pressure Requirements Line Pressure: Minimum Minimum 11" W C*, Maximum 14" 14" W C *WC - water column Vo lta ge Re qu ire m en ts Voltage DC: 12 volt D.C. Minimum 10.5 volts D.C., Maximu m 13.5 volts D.C.
Service Tools Required Manometer gauge/ U-Tube Volt ohm meter capable of testing above 15 amps Module board tester #641511 Gas leak detector OR approved leak check liquid As so rte d wren wr en ch es As so rte d h an d too t oo ls Safety glasses
3
Suburban RV FURNACES 12 VDC Direct Discharge
BT B TU/h Input
Height
Width
Depth
Ignition
Shipping Weight
NT-12SE NT-16SE NT-20SE DD-17DSI
12,000 16,000 19,000 17,000
9 3/8" 9 3/8" 9 3/8" 12"
9 3/8" 9 3/8" 9 3/8" 10 1/2"
21-27 3/4" 21-27 3/4" 21-27 3/4" 22-29"
Electronic Electronic Electronic Electronic
27 27 27 25
Accesso ri ries 260197 260198 260199
Descr ip iption Vent Kit 2" - 4" DD Models Vent Kit 4" - 6" DD Models Vent Kit 6" - 9" DD Models
12 VDC Ducted BTU/h Furnaces Input
Height
W idth
Depth
Ignition
Shipping W eight
NT-12S NT-16S NT-20S NT-24SP NT-30SP NT-34SP NT-40
12,000 16,000 19,000 24,000 30,000 34,000 40,000
9 3/8" 9 3/8" 9 3/8" 12 1/2" 12 1/2" 12 1/2" 12 1/2"
9 3/8" 9 3/8" 9 3/8" 12" 12" 12" 12"
22 3/4-29 1/2" 22 3/4-29 1/2" 23 3/8-30 1/8" 23" 23" 23" 23"
Electronic Electronic Electronic Electronic Electronic Electronic Electronic
27 27 27 40 40 40 42
SF-20F SF-25F SF-30F SF-35F SF-42F SH-35F SH-42F SF-20* SF-25* SF-30* SF-35* SF-42* SH-35* SH-42* SHD-2542
20,000 25,000 30,000 35,000 40,000 35,000 40,000 20,000 25,000 30,000 35,000 40,000 35,000 40,000 25/40,000
7 1/2" 7 1/2" 7 1/2" 7 1/2" 7 1/2" 9 1/4" 9 1/4" 7 1/2" 7 1/2" 7 1/2" 7 1/2" 7 1/2" 9 1/4" 9 1/4" 9 1/4"
17" 17" 17" 17" 17" 17" 17" 17" 17" 17" 17" 17" 17" 17" 17"
Electronic Electronic Electronic Electronic Electronic Electronic Electronic Electronic Electronic Electronic Electronic Electronic Electronic Electronic Electronic
35 35 35 35 35 40 42 35 35 35 35 35 40 42 44
Accessories 6258 6258AC ACW W 6258 6258AP APW W 6267 6267AC ACW W
20" 20" 20" 20" 20" 20" 20" 20" 20" 20" 20" 20" 20" 20" 20"
Description *Doo *Door, r, Opti Option onal al Acc Acces ess, s, Col Colon onia iall Whit White, e, Stan Standa dard rd SF Mod Model els s *Doo *Door, r, Opti Option onal al Acce Access ss,, Pol Polar ar Whit White, e, Stan Standa dard rd SF Mode Models ls *Doo *Door, r, Opti Option onal al Acc Acces ess, s, Col Colon onia iall Whit White, e, Stan Standa dard rd SH Model odels s
120 VAC Park BTU/h Model Fu F urnaces Input
Height
W idth
Depth
Ignition
Shipping W eight
P-40
12 1/2"
12"
23"
Electronic
46
Accessories 050733 050715 051240 280552 0 62 6216 4 0 70 7085 3 5 20 2000 9 5205 520576 76 520753 520864
40,000
Description Duct Cover Duct Collar 4" Duct Collar 2" Rain Shield Bottom Duct Gasket, NT-24/30/34SP, NT -4 -40, P40 Bottom Duct Gasket, SF Mode ls ls Except SF -4 -42, (F) Bottom Du Duct Ki Ki t W /G /G as asket, NT NT -2 -2 4/ 4/30/34SP, NT NT-40. P4 P40 Botto ottom m Du Duct Kit W/Ga W/Gask sket et,, SF SF Mod Model els s Ex Except cept SF-4 SF-42, 2, (F) (F), SH SH35 (F) Bottom Du Duct Ki Kit W/ W/Gasket an and Do Door, SF SF-42, (F (F) Bottom Duct Kit W /Gasket SH-42 (F) SHD-2542
Wall Thermostats are included with All Models, except SF. Ve nt As se m bl ie s ar e inc lu de d wi th all un its , e xc ep t D D.
4
INSTALLATION There are several important aspects of the installation which will pertain to all Suburban forced draft furnaces, regardless of the model or the method in which they are installed. T hey are: 1. 2. 3. 4.
Sele Select ctin ing g a Loca Locati tion on Venting Return Air Ducting
Refer to the furnace installation manual for all installation requirements. Location and InstallationInstallation - Locate the furnace near lengthwise center of the coach. Choose a location for installation out of the way of wires, pipes, etc. which might interfere with the installation. Adhere to the minimum clearances from cabinet to combustible construction as listed in the installation manual for your specific furnace model. Secure furnace cabinet to the floor of the the coach using the holes provided in the furnace cabinet.
Figure 1
5
VENTING Venting Venting- By definition of a Direct Vent Sealed Combustion Furnace, it must be vented to the outside atmosphere and also draw combustion air from outdoors. Therefore, it is imperative that the vent be unobstructed and there must be a seal between the exhaust and intake (caulking) . Refer to the vent assembly installation in the manual. The vent must be straight. There can be no offsets or turns in the vent. All vent tubes which connect to the furnace exhaust and intake must overlap a minimum of 1/2" on intake, and 1 1/4" on exhaust. Check your furnace model number for vent installation procedures. Vents cannot be altered as supplied from the factory. VENT ASSEMBLY ASSEMBLY INSTALLATION INSTALLATION (SF and SH SERIES)
Figure 2 SF
Figure 2A SH
6
VENT ASSEMBLY ASSEMBLY INSTALLATION INSTALLATION (SF and SH SERIES)
Figure 3 SF
Figure 3A SH and SHD-2542
7
VENT ASSEMBLY ASSEMBLY INSTALLATION INSTALLATION (SF and SH SERIES)
Figure 4 SF
Figure 4A SH
8
VENT ASSEMBLY INSTALLATION INSTALLATION (SFV)
Figure 5
Figure 5A
9
Figure 6
Figure 6A
10
VENT ASSEMBLY ASSEMBLY INSTALLATION INSTALLATION (DD SERIES) SERIES) Note: Vent cap must be installed on DD furnace when bench testing.
Figure 7
11
VE NT ASSE AS SE M BL Y INST IN ST AL LATI LA TI ON (N T SE RIES RI ES )
Figure 8 NT-12/16/20SE
Figure 9 NT-12/16/20S and SE
Figure 10 NT-12/16S
12
VE NT ASSE AS SE M BL Y INST IN ST AL LATI LA TI ON (N T SE RIES RI ES )
Figure 11 NT-20S
Figure 12 NT-24/30/34SP P-30S
13
VE NT ASSE AS SE M BL Y INST IN ST AL LATI LA TI ON (N T SE RIES RI ES )
Figure 13 NT-24/30/34SP P-30
EXTENSION TUBE KIT NUMBER
MIN./MAX. LENGTH (Extension (Extension Tube Range)
520498
2-1/4" to 3-1/8"
520499
3-1/8" to 4-7/8"
520500
4-7/8" to 7"
520501
7" to 9" Figure 14 NT-24/30/34SP P-30S
EXTENSION TUBE KIT NUMBER
MIN./MAX. LENGTH (Extension (Extension Tube Range)
520593
2-1/4" to 3-1/8"
520594
3-1/8" to 4-7/8"
520595
4-7/8" to 7"
520596
7" to 9" Figure 15 NT-40 P-40
14
VE NT ASS EM BL Y INST IN ST ALLA AL LA TIO TI O N (N T- 40 an d P-40 P- 40 )
Figure 16 NT-40
Figure 17 P-40
15
Figure 18 NT-40 P-40
RETURN AIR Return Air - The ca binet that the furnace may be installed in will will have louvers or openings for the return air back to the furnace. W hen the furnace is installed, itit is impe impe rative that that the return air louvers louvers on the furnace cabinet open ing are not obstructed. Usually, these furnaces are installed under a c ounter, sofa or bed in order to be o ut of the way. A grille grille or opening m ust be built into into the cabinetry or into the base area of the s ofa or bed. Return air from the living area of the trailer trailer is drawn in through the grille and into the return air openings in the furnace cabinet. Figure 19 illustrates the return air circulation of the furnace. Note: Refer to the installation manual for the minimum return air area for your specific furnace model. Insufficient return air will will cause the furnace to overheat and cycle on limit. Another symptom of a re turn air problem is: is : 1.
Furnace seem s to run continuously in an effort to satisfy satisfy the the thermostat.
*THE TOTAL, FREE, UNOBSTRUCTED RET URN AIR OPENING TO THE FURNACE MUST NOT BE LESS THAN THE MINIMUM
Figure 19
16
DUCTING Ducting Ducting - Suburban furnaces requ ire that a minimu m duct area be maintained throughout entire duct system including through the register. It is is very important to adhere to the the minimu m duct area in order to kee p the furnace from cycling on high limit and to assure proper opera tion of the the sail switch (sometimes referred to as a m icroswitch.) NOTE: (Refer to the installation manual for the minimum ducted square inches area for each model.) NOT E: Ducts terminating in a dead air space (like holding tank compartments or cargo areas (Toy Boxes) w ith no means for return air recirculation should not be counted in the required duct area. Also, ducts 2" in diameter or smaller should not be counted in the required duct area. W hen installing installing a duct system, avoid m aking a lot of turns. turns. The straighter the duct system, the less the resistance to air flow and the better the the performa nce of the furnace. Av oid m ak ing sh ar p tu rns rn s in i n th e d uc t syst s ystem em . Sh arp ar p tur t urns ns will wil l incr in crea ea se the sta tic pres pr es su re in t he ple nu m area ar ea of the furnace and co uld cause the furnace to cycle on limit. The du ct connections to the furnace cabinet should be tight to eliminate any heat loss which could resu lt in in overheating of the compo nent parts on the furnace as well as a reduction in the heated air flow flow through the ductwork.
Figure 20
17
S T N E M E R I U Q E R N O I T A L L A T S N I
r i A h c n n r i u q t e S R
a / n
" 5 5
" 5 5
" 5 5
a / n
a / n
a / n
" 5 5
" 5 5
" 5 5
" 3 1 1
" 5 5
" 3 1 1
t c u D h e c d n i I S q R S & L
a / n
" 5 2
" 5 2
" 5 2
a / n
a / n
a / n
" 6 3
" 6 3
" 8 4
" 8 4
" 8 4
" 8 4
t c h u c n D I p q o S T
a / n
a / n
a / n
a / n
a / n
a / n
a / n
a / n
a / n
a / n
a / n
a / n
a / n
t c h u c n D I m q t S B
a / n
a / n
a / n
a / n
a / n
a / n
a / n
" 8 4
" 8 4
" 8 4
" 8 4
" 8 4
" 8 4
d ’ q e R s t c u D
a / n
" 4 2
" 4 2
" 4 2
a / n
a / n
a / n
" 4 3
" 4 3
" 4 4
" 4 4
" 4 4
" 4 4
t r h " l g 0 C i R
" 1
" 1
" 1
" 8 / 5
" 8 / 5
" 8 / 5
" 1
" 1
" 2
" 2
" 1
" 2
r t f l e C L
" 0
" 1
" 1
" 1
" 8 / 5
" 8 / 5
" 8 / 5
" 1
" 1
" 2
" 2
" 1
" 2
r k c l C a B
" 0
" 0
" 0
" 0
" 0
" 0
" 0
" 0
" 0
" 0
" 0
" 0
" 0
r m " l t C B 0
" 0
" 0
" 0
" 0
" 0
" 0
" 0
" 0
" 0
" 0
" 0
" 0
r p l o C T
" 1
" 1
" 1
" 8 / 5
" 8 / 5
" 8 / 5
" 0
" 0
" 0
" 1
" 0
" 1
" 8 / 3
" 8 / 3
" 1
1 * e e S
1 * e e S
1 * e e S
" 0
" 0
" 0
" 1
" 0
" 1
S 2 1 T N
S 6 1 T N
S 0 2 T N
E S 2 1 T N
E S 6 1 T N
E S 0 2 T N
P S 4 2 T N
P S 0 3 T N
P S 4 3 T N
0 4 - 0 T 3 N P
0 4 P
t n o r F r l C
s l e d o M
" 0
1 * e e S
I S D 7 1 D D
. d e s . u l a e r u a n s a t M c u n d o 5 i t c f i u r " t 8 s 8 n I o d t n d a e n c u o i t d r a e l l e a b t s y n a I o M t r . e d f e e s R u . e s r ) l a s l i r s e g t g n e c u l a g f r d ( a 4 r h f e c i c s " a i d 2 p r 4 s o 1 o f e t s b s e d i c l e n u c a r o n a a h r e s l r a i c a l e l a n c i r " c u e t 0 p e : E S R T - 1 2 O * * N
S T N E M E R I U Q E R N O I T A L L A T S N I
r i A h c n n r i u q t e S R
" 5 5
" 5 5
" 5 5
" 5 5
2 * E E S
" 5 5
2 * e e S
2 * E E S
t c u D h e c d n i I S q R S & L
" 5 2
" 6 3
" 6 3
" 8 4
" 8 4
" 8 4
" 8 4
" 8 4
t c h u c n D I p q o S T
" 6 5
" 6 5
" 6 5
" 6 5
" 6 5
" 6 5
" 6 5
" 6 5
" 6 5
3 * E E S " 2 7
3 * E E S " 2 7
t c h u c n D I m q t S B
" 6 5
" 6 5
" 6 5
" 6 5
3 * E E S " 2 7
d ’ q e R s t c u D
" 4 2
" 4 3
" 4 3
" 4 4
" 4 4
" 4 4
" 4 4
" 4 4
t r h " l g 0 C i R
" 0
" 0
" 0
" 2
" 1
" 2
" 2
r t f l e C L
" 0
" 0
" 0
" 0
" 2
" 1
" 2
" 2
r k c l C a B
" 0
" 0
" 0
" 0
" 0
" 0
" 0
" 0
r m " l t C B 0
" 0
" 0
" 0
" 0
" 0
" 0
" 0
r p l o C T
" 0
" 0
" 0
" 0
" 1
" 0
" 1
" 1
t n o r F r l C
" 1
" 1
" 1
" 1
" 1
" 1
" 1
" 1
F 0 2 / 0 2 F S
F 5 2 / 5 2 F S
F 0 3 / 0 3 F S
F 5 3 / 5 3 F S
F 2 4 / 2 4 F S
2 4 5 5 2 2 3 - 4 - D H H H S S S
s l e d o M
. 4 . 6 d . e 8 l 0 a s 2 u u 5 n s # a t c t i M u k n d s o 5 e i t f s c i u " u 2 r t 8 4 s 8 5 n o 2 I t d d D n e a t H c n u S o d d i t e n a r a l l a e 2 t b 4 s y n a H I o M S t , r . 3 e d 5 f e 7 e s R u 0 2 . e 5 ) l s r # a s i l e r s t i g g t k n e c s u a l g d e f r s ( r a 4 u f e h i 2 c c s " 4 a i 2 F p d S s r 4 o 1 . o f e d t b e s s e r i i d l u e c u q c n o e n a r h r a s t r a e r c a l i u e c a d l c l a n " i r m 0 c u t o t : e p e t E S R o T - - B O 1 2 3 N * * *
S T N E M E R I U Q E R N O I T A L L A T S N I
r i A h c n n r i u q t e S R
" 5 5
" 5 5
" 5 5
" 5 5
" 2 4 1
t c u D h e c d n i I S q R S & L
4 * E E S
4 * E E S
4 * E E S
4 * E E S
4 * E E S
t c h u c n D I p q o S T
4 * E E S
4 * E E S
4 * E E S
4 * E E S
4 * E E S
t c h u c n D I m q t S B
" 2 5
" 2 5
" 2 5
" 2 5
" 2 5
d ’ q e R s t c u D
4 * E E S
4 * E E S
4 * E E S
4 * E E S
4 * E E S
t r h " l g 1 C i R
" 1
" 1
" 1
" 1
r t f l e C L
" 1
" 1
" 1
" 1
" 1
r k c l C a B
" 0
r m " l t C B 0 r p l o C T t n o r F r l C
s l e d o M
" 1
" 0
" 0
" 1
" 0
" 0
" 1
" 0
" 0
" 1
" 0
" 0
" 2
" 1
" 1
" 1
" 1
" 1
F 0 2 / 0 2 V F S
F 5 2 / 5 2 V F S
F 0 3 / 0 3 V F S
F 5 3 / 5 3 V F S
F 2 4 / 2 4 V F S
e b t s u m w o l e b d e t s i l s a e r a t c u d n e p o m u m i n i m e h T . e c a n r u f e h t f o n o i t a r e p o r e p o r p e r u s s a o t r e d r o n i d e w o l l o f e b t s u m s t . n 4 e . 6 m d e . e 8 r l 0 i a s 2 u u u 5 q n s # e r a t c t i t M u k c n d s u o 5 e d i t f s e c i u h " u 2 T r t 8 4 s 8 5 . s n o 2 t I t . - n r d d D e e t n e s a t H m i c e n u S i r g o d d u e i t e n q r a r a e h l l r g a e 2 u t b 4 o s y - g r n i h n H t I a S c t o M u g t , n r . 3 d i e d 5 r d f o u e 7 f e s l c R u 0 2 w i o n . e 5 l r ) l s e m s i l a # b e e r s t i e t g g t k l s n e c s b y u a s a l g d e t f t r s ( c r a 4 u w u f e h e i 2 i d c c s " 4 v a i 2 F e e r i p d r t s r 4 1 S e n . o o f e d c e t a e b e s s r n i e d i r h l u u t e c f u q c n t h o e n a r h r n g u a s t u r a e r c o o r a l i u h e c a d m t l l c l a n a d " i r m c e 0 c u t i n o t t t r i : e p e o e a t E R n V i T S - - B - - a O 1 2 3 4 N * * * * m
l a n o i t p O *
T T H C G U I R D
l a n o i t p O *
. N I . Q S 2 7
l a n o i t p O *
T T F C E U L D
a m e u r A m t i n c i u M D
l a n o i t p O *
. N I . Q S 6 5
. N I . Q S 6 5
M O T T O B
a m e u r A m t i n c i u M D
2 2 2 . 5 . 5 . 5 . N d N d N d N I . I I I e e e r . i r . i r . Q i u Q u Q u Q S q S q S q S 2 e e e 5 R R R
. N I . Q S 2 5
l a n o i t p O *
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l a n o i t p O *
l a n o i t p O *
e m b o t o t T o t B o ) ( . N d t e N I c s . u U Q D S t n 8 o 4 r F
) F ( 0 2 V F S
) F ( 5 2 V F S
) F ( 0 3 V F S
) F ( 5 3 V F S
L E D O M
. t c u d m o t t o b e h t f o e s u d e r i u q e r e h t o t
t n n o o i r e t i F B d p o d ) o T . a T n ( t d i e . o s e N r I N U a . t c s Q u t c S D u 8 d 4 e ) s e F ( h t 2 f 4 o V e F s S U *
FURNACE SPECIFICATIONS 12 VDC Model
Description
Input BTU/hr
Type Gas
Voltage
Motor Diameter
Amp Draw
Static Pressure
C.F.M. Max.
DD-17DSI
Direct Discharge
17,000
PROPANE
12 VDC
3"
2.9
n/a
145
NT-12S
Ducted
12,000
PROPANE
12 VDC
3"
2.8
S - .1" wc
S - 122
NT-12SE
Direct Discharge
SE - n/a
SE -140
NT-16S
Ducted
S - .1" wc
S - 165
NT-16SE
Direct Discharge
SE - n/a
SE-140
NT-20S
Ducted
S - .1" wc
S - 165
NT-20SE
Direct Discharge
SE-n/a
SE-150
NT-24SP
Ducted
24,000
PROPANE
12 VDC
2.5"
3.5
.2" wc
265
NT-30SP
Ducted
30,000
PROPANE
12 VDC
2.5"
5.5
.2" wc
345
NT-34SP
Ducted
34,000
PROPANE
12 VDC
2.5"
7.5
.1" wc
373
NT-40
Ducted
40,000
PROPANE
12 VDC
2.5"
9.5
.155"/.20B
441
Park Models
Ducted
30,000
PROPANE
120 VAC
3"
2.5
.15" wc
345
Ducted
40,000
PROPANE
120 VAC
3"
2.0
.15" wc
441
16,000
19,000
PROPANE
PROPANE
12 VDC
12 VDC
3"
3"
2.8
2.8
P-30S P-40** NOTES **P-40 Park Model Furnace and valve is convertible to Natural Gas. Instructions on converting unit to Natural Gas are on sticker on side of cabinet.
21
FURNACE SPECIFICATIONS 12 VDC Model
Description
Input BTU/hr
Type Gas
Voltage
Motor Diameter
Static Pressure
C.F.M. Max.
SF-20/20F
Ducted
20,000
PROPANE
12 VDC
3"
6.5=2.5 in. Motor 8.5=3 in. Motor
.2" wc
300
SF-25/25F
Ducted
25,000
PROPANE
12 VDC
3"
6.5=2.5 in. Motor 8.5=3 in. Motor
.2" wc
300
SF-30/30F
Ducted
30,000
PROPANE
12 VDC
3"
6.5=2.5 in. Motor 8.5=3 in. Motor
.2" wc
300
SF-35/35F
Ducted
35,000
PROPANE
12 VDC
3"
8.5=2.5 in. Motor 9.4=3 in. Motor
.2" wc
375
SF-42/42F
Ducted
40,000
PROPANE
12 VDC
3"
11.5
.25" wc
430
SFV-20/20F
Ducted
20,000
PROPANE
12 VDC
3"
8.5
.2" wc
300
SFV-25/25F
Ducted
25,000
PROPANE
12 VDC
3"
8.5
.2" wc
300
SFV-30/30F
Ducted
30,000
PROPANE
12 VDC
3"
8.5
.2" wc
300
SFV-35/35F
Ducted
35,000
PROPANE
12 VDC
3"
9.4
.2" wc
375
SFV-42/42F
Ducted
40,000
PROPANE
12 VDC
3"
11.5
.25" wc
430
SH-35/35F
Ducted
35,000
PROPANE
12 VDC
3"
8.2
.2" wc
375
SH-42/42F
Ducted
40,000
PROPANE
12 VDC
3"
10.6
.25" wc
430
SHD-2542
Ducted
25,000
PROPANE
12 VDC
3"
8.8 (Low)
.25" wc
430
42,000
Amp Draw
12 (High)
22
SEQUENCE OF OPERATION For Furnaces Equipped With Time Delay The therm ostat controls the operating circuit to the furnace by reacting to room room tem perature to open and close a set of contact points which allows current to flow to the ON and OFF s witch then to the relay. The relay receives the power and allows power to pass through to the switch within the relay. This is done by a heater coil within the the relay which actuates a bi-m etal disc closing the relay circuit. The power then flows to the motor and allows the blower to operate. One end of the motor shaft drives the room air wheel. The other end of the motor shaft drives the combustion air wheel that delivers the required air to the burner for combustion. The limit switch is an in-line device which protects the furnace from over heating conditions. The contacts in the limit switch open at a given temperature setting, shutting shutting off power to the ignition ignition system wh ich controls the gas valve. As the room ro om air wh ee l com c om es up to sp ee d, air flo w clo se s the sail switch completing the circuit. The sail switch is placed into the system as a safety to prove there is adequate air for combustion. The next operation is controlled by the Direct Spark Ignition, Ignition, (DSI) system as pow er is applied to the DSI board. The system will do the following. following. 1. The 1. The board has a timing circuit which allows the blower to purge the chamber of any products of combustion or gas. 2. The 2. The board will then apply power to the gas valve. At the same time it produces a high voltage power supply to the electrode producing spark at the burner. 3. The 3. The board will also confirm the presence of a flame. If the flame is not sensed after 7 sec onds, the m odule will try two (2) more times and then go into lock-out. The flame is sensed through the spark wire and electrode. W hen the the thermos thermos tat has reached the set point with the room air temperature, the contacts will open removing power from the controls. The blower w ill rema in on until the the relay opens and stops the motor. NOTE: On some models, sail switch is before limit switch.
23
Sequence of Operation for Fan Control Module Board Part Number 520820
Time Line Start
Thermostat Calls for Heat
15 Seconds Purge Cycle
Description - Sequence of Events The wall thermostat controls the operation of the furnace by reacting to room temperature, this allows current to flow through the On/Off switch to the module board. The module board constantly checks for a minimum 9.5 volts. If there is not 9.5 volts, the module board will go into a stand by mode until adequate power is supplied. It will then resume normal operation. Upon a call from the thermostat, the module board thermostat circuit will go active. The sail switch circuit is verified as being open. The blower output is energized. Blower motor starts. The module board will then verify that the sail switch circuit is closed and motor is up to speed. If this circuit remains open for 30 seconds after the blower motor starts, the module board will go into lock out and shut down the blower motor. The module board checks that the gas valve relay contacts (which are located on the module board) are open before the ignition sequence starts. The board has a pre-purge timing circ uit of (approximately 15 seconds). This allows the chamber to purge.
7 Seconds Ignition Cycle and Flame Sense
The module board will energize the gas valve and enable the high voltage spark output to the electrode for 7 seconds of ignition time. The module board will then check for flame sense to verify successful lighting of the main burner flame. Sparking will then be terminated and the gas valve and blower outputs will remain energized. If ignition is successful the modu le board will monitor the flame sense, sai l switch and limit switch circuits, and the thermostat inputs during the heating period. The flame is sensed throu gh the spark wire and electrode. Therefore, it is essential tha t the electrode is properly positioned in the burner flame.
2nd and 3r d Ignition Cycles if Required
3 Try Ignition Board
Heat Heatin ing g Cycle Cycle
If duri during ng the the hea heati ting ng cyc cycle le,, the the limi limitt swit switch ch circ circui uitt opens opens and and remai remains ns open open for for 5 minutes, the module board will go into loc k out and shut down the blower motor. If this occurs, the thermostat will need to be reset for the furnace to operate.
90 Second Shut Down
When the thermostat has reached its set point and the demand for heat ends, the gas valve will be de-energized and the flame will go out. The post purge period of 90 seconds begins. W hen it times out, the blower motor output is removed, and the blower stops.
If the flame is not sensed after seven (7) seconds, a second 15 second purge cycle will begin followed by a second Trial-For-Ignition sequence . After three (3) Trial-For-Ignition attempts with no ignition of the main burner, the module board will de-energize the gas valve immediately and blower will run for 3 minutes and then shutdown in lockout.
24
Sequence of Operation for 24 VAC Fan Control Module Board Part Number 520947
Time Line Start
Description - Sequence of Events The wall thermostat controls the operation of the furnace by reacting to room temperature, this allows current to flow through the On/Off switch to the module board. The module board must have a minimum 18 volts for normal operation.
Thermostat Calls for Heat
15 Seconds Purge Cycle
Upon a call from the thermostat, the module board thermos tat circuit will go active. The sail switch circuit is verified as being open. The blower output is energized. Blower motor starts. The module board will then verify that the sail switch circuit is closed and motor is up to speed. If this circuit remains open blower motor will run continuously until sail s witch closes. The module board checks that the gas valve relay contacts (which are located on the module board) are open before the ignition sequence starts. The board has a pre-purge timing circuit of (approximately 15 s econds). This allows the chamber to purge.
7 Seconds Ignition Cycle and Flame Sense
The module board will energize the gas valve and enable the high voltage spark output to the electrode for 7 seconds of ignition time. The module board will then check for flame sense to verify successful lighting of the main burner flame. Sparking will then be terminated and the gas valve and blower outputs will remain energized. If ignition is success ful the module board will monitor the flame sense, sail switch and limit switch circuits, and the thermostat inputs during the heating period. The flame is sensed through the flame sence electrode. Therefore, it is essential that the electrode is properly positioned in the burner flame.
2nd and 3r d Ignition Cycles if Required
3 Try Ignition Board
Heat Heatin ing g Cycle Cycle
If duri during ng the the heat heatin ing g cycle cycle,, the the limi limitt swit switch ch circu circuit it open opens s and and rema remain ins s open open the the gas gas valve valve will close and the blower motor will continue to run.
90 Second Shut Down
When the thermostat has reached its s et point and the demand for heat ends, the gas valve will be de-energized and the flame will go out. The post purge period of 90 seconds begins. W hen it times out, the blower motor output is removed, and the blower stops.
If the flame is not sensed after seven (7) seconds, a second 15 second purge cycle will begin followed by a second Trial-For-Ignition sequence . After three (3) Trial-For-Ignition attempts with no ignition of the main burner, the module board will de-energize the gas valve immediately and blower will run for 90 seconds and then shutdown in lockout.
25
Sequence of Operations for SHD-2542 1st Stage Call for Heat The wall thermostat controls the operation of the dual stage furnace by reacting to room tem perature. This allows current to flow through the On/Off switch to the Blower Speed Control Board then to the Module Board. The m odule board cons tantly checks for a minimum 9.5 volts. If If there is not 9.5 volts, volts, the module board will go into into a standby mode u ntil adequate power is sup plied. It It will then resume normal operation. Upon a c all from the thermostat the first stage will be activated. The m odule board therm ostat circuit will go active and the sail switch is verified verified as being open. The blowe r output is energized. The blower motor starts.
15 Second Purge Cycle The m odule board will then verify that that the sail switch circuit is closed and m otor is up to speed . If this this circuit remains open for 30 seconds after the blower motor starts, the module board will go into into lockout and shut down the blower m otor. The module board checks that the gas valve relay contacts (located on the module board) are open before the igniting sequence starts. The board has a pre-purge timing circuit of approximately 15 seconds. This allows the combustion chamber to purge. 7 Second Ignition Cycle and Flame Sense The m odule board will energize the the gas valve and ena ble the high voltage voltage spark o utput to the the electrode for a seven s econd ignition ignition period. The m odule board will then check for flame sense to verify successful lighting of the the main burner flame . Sparking of the igniter is then terminated. The gas valve and blower outputs will remain energized. If ignition ignition is success ful the module board will monitor the flame sense, sa il switch, and the limit switch circuits. circuits. The flame is sensed throu gh the spark wire an d electrode therefore , it is is esse ntial that that the electrode is properly positioned in the burner flame.
3 try Ignition Board If the flame is NOT sensed after seven (7) seconds, or if the unit fails to ignite, a second fifteen (15) purge cycle will begin followed by second trial for ignition ignition sequ ence. After three (3) trial for ignition ignition attemp ts with no ignition of the main burner, the modu le board will de-energize the gas valve imm ediately and the blower will will run for three (3) minutes and then g o into lockout mode.
2nd Stag Stage e Heat Heatin ing g If during the the thermostat cycle the dema nd for heat drops below the second stage therm ostat setting setting ( 3 to 5 degrees variance depending on thermostat manufacturer), the blower speed control board will be energized. The blower speed control board will energize the additional gas valve solenoid and increase m otor speed to the high position. Furnace will remain in the second stage operation until thermos tat is satisfied.
90 Second Shut Down W hen the thermo stat has reached its set point point and the demand for heat ends , the gas valve will will be de-energized and the flame will go out. The post com bustion purge period of 90 seco nds begins. W hen it times times out, the blower motor output is removed, and the blower stops.
26
TROUBLE SHOOTING GUIDE SUBURBAN RV FURNACES with TIME DELAY 12 VDC HEATING SECTION Thermostat closes
-No-
Check thermostat wire connections, contact points and the heat anticipator.
-Yes-
Clean points, secure loose connections, replace thermostat if An tic ipa tor is sh ort ed .
No
Check 12vdc at blue wire, check the amp draw to thermostat.
Ye s
-Yes-
Replace thermostat.
No
Check for shorts. Check com ponents amperage.
-Yes-
Repair or replace connections or parts with higher than normal amp draw.
-No-
Check on/off switch on furnace
-No-
Replace fuse/Reset breaker
-No-
Replace the time delay relay.
Check ground wire on terminal block.
-No-
Replace the motor.
Check for 12vdc between red and yellow wires at the module board.
-Yes-
Check plug connection to the mModu le-electrode and wire-spark gap 1/8 inch between probe and ground.
-Yes-
Replace the sail switch.
Ye s
C h e c k f o r 1 2 v d c a t fu rn a c e Ye s
C h e c k f u s e o r c i rc u it b re a k e r Ye s
Ap pro xim at ely 10 -20 se co nd s Blower is operating
-No-
Check for 12v dc at time delay relay and for 12vdc to red w ire leading to the motor. Ye s
Ye s
Af te r 1 5 se co nd s the m od ule creates spark and opens valve.
-No-
No
Check for 12vdc at limit switch, both sides.
Ye s
No
Check for 12vdc at sail switch both sides.
-Yes-
Replace the limit switch.
Spark occurs for approximately 7 seconds and main burner flame establishes.
No spark at the electrode -No-
-No-
Replace the module.
Ye s
Check for 12vdc at gas solenoid valve.
-No-
Replace the module.
Ye s
Did the gas valve open.
-No-
Ye s
Ye s
Check g as pressure at the manifold or for restrictions restrictions in the burner orifice. No
Check for restriction restriction in combus tion air Intake Intake (wasps, etc.)
Replace the gas valve.
No
Thermostat opens and the time delay operates the fan for the cool down cycle.
Is flame established.
-No-
Check flame contact to electrode. Flame should be hard blue.
-No- Replace the time delay relay.
Ye s
System Ok
NOTE: On some models, sail switch is before limit switch.
27
TROUBLE SHOOTING GUIDE SUBURBAN RV FURNACE with FAN CONTROL MODULE BOARDS 12 VDC HEATING SECTION Thermostat Closes
-No-
Check thermostat wire connections, contact points and the heat anticipator.
-Yes-
Clean points, secure loose connections, replace thermostat if anticipator is shorted.
-Yes-
Replace thermostat.
-Yes-
Repair or replace connections or parts with higher than normal amp draw.
-No-
Check on/off switch on furnace
-No-
Replace fuse/Reset breaker.
No
Check 12vdc at blue wire, check the amp draw to thermostat.
Ye s
No
Check for shorts. Check com ponents amperage.
Ye s
C h e c k fo r 1 2 v d c a t fu rn a c e Ye s
C h e c k f u s e o r c i rc u it b re a k e r Ye s
Blower is operating at call for heat.
-No-
Check for 12vdc at power terminal on module board and for 12vdc to red wire leading to the motor.
-No-
Replace the module board after confirming motor operation.
Ye s
Ye s
Check ground wire on terminal block.
-No-
Replace the motor.
Reset thermostat. Motor operating. Check for 12 vdc at blue wire on molex edge connector.
-Yes-
Verify voltage thru limit and sail switch to module board. If circuit remains open for 30 seconds, m odule board will go into lockout and shut down motor. Reset thermostat. Replace defective part.
Check for 12vdc between red and yellow wires at the module board.
-Yes-
Check plug connection to the module-electrode and wire-spark gap 1/8 inch between probe and ground.
-Yes-
Replace the sail switch.
Check for 12vdc at sail switch both sides.
-Yes-
Replace the limit switch.
No spark at the electrode
-No-
Replace the module.
-No-
Replace the module.
Motor is operating
-No-
Ye s
Af te r 1 5 se co nd s the m od ule creates spark and opens valve.
-No-
No
Check for 12vd c at limit switch, both sides.
Ye s
No
Spark occurs for approximately 7 seconds and main burner flame establishes.
-No-
Ye s
Check for 12vdc at gas solenoid valve.
Ye s
Did the gas valve open.
-No-
Ye s
Ye s
Check g as pressure at the manifold or for restrictions in the burner orifice. No
Check for restriction restriction in combustion air Intake (wasps, etc.)
Replace the gas valve.
No
Thermostat opens and the module board operates the fan for the cool down cycle.
Is flame established.
-No-
Replace the module board
Ye s System Ok
28
-No-
Check flame contact to electrode. Flame should be hard blue.
SERVICE HINTS, DIAGNOSIS, AND CORRECTIVE MEASURES FOR THE IGNITION SYSTEMS OF SUBURBAN 24 VOLT ELECTRONIC IGNITION GAS FURNACES WITH TIME DELAY
CAUTIONS:
4. Be sure the electrode assembly screws are snug at all times, especially after the electrode has been removed and reinstalled. 5. If the module board is found to be defective, it must be replaced - it is not field repairable. Any attempts to repair the board board may alter the board and cause it to operate in an unsatisfactory manner. 6. Insure that the gap between electrode and ground is always 1/8". The gap between the flame sensor should be approximately twice the gap between electrode and ground to insure no no sparking to sensor. Sparking to sensor will damage the module board.
1. Never operate the furnace with the electrode wire disconnected nor with the electrode assembly removed from the furnace. 2. Never use a screwdriver on any part of the electrode assembly while the furnace is in operation. 3. Be certain that the spark from the electrode never reaches the flame sensor portion of the electrode assembly.
The electronic ignition system is made up of three main parts; the module board, the electrode assembly, and the electrode wire. The m odule board is the brain of the electronic ignition system and it has several functions. 1. 1. When the blower reaches approximately 75% of the normal r.p.m. and sufficient air flow is established, the sail switch engages and completes a 24 volt circuit through the limit switch to the module board. 2. 2. After a 12 - 18 second delay, 24 volt current will pass through the module board to the solenoid valve. The current to the valve opens it and allows gas to the main burner; burner; simultaneously, the module board sends high voltage through the electrode wire to the electrode assembly. The voltage seeks a ground between electrode and ground probe and a spark occurs. The spark then ignites the main burner.
It is important to determine the type problem being experienced, then the proper checkout procedure can be made. The following is a list of problems, how to identify in which area the problem is located, and how to correct it. 1. Electrode not sparking sparking - with blower running and micro switch engaged, check the following: a. Check for proper voltage at module board after the blower motor reaches full r.p.m. If no voltage, check continuity through micro switch and limit switch. Also check wiring and wire wire connections. b. Voltage is present but no spark at electrode after 12 - 18 second delay, check electrode wire connections. c. Wire connections OK, but electrode wire does not show continuity through it - replace electrode wire. d. Electrode wire does show continuity through it - check electrode gap to be sure it is 1/8" maximum between electrode and ground. NOTE: Gap between sensor and ground must be twice electrode gap. e. Electrode gap OK - check electrode assembly for possible cracks or carbon on tip of electrode. f. Electrode OK - replace module board. 2. Electrode sparking, but gas not coming through burner: a. Check to see if voltage is coming out of module board to gas valve after the 12 - 18 second delay. Check the wires in the molex connector to be sure they are intact and making contact with the module board. Check wire from the module board to valve for continuity. Wire and connections check OK - replace module board. b. Voltage is coming out of module board to gas valve, but gas valve does not open - replace gas valve. 3. Electrode sparking and gas valve opening, but burner will not light: a. Check to see if gas is coming through to the burner. This can be accomplished by using a flow meter in the gas supply line. If no gas is coming through the burner, check for obstruction in gas line, in main burner orifice, or in main burner. burner. b. Gas is coming through burner, but spark will still not ignite burner - check gas pressure. Line Pressure - Min. 11" W.C.*, Max. Max. 14" W.C. To properly check pressure, first determine the line pressure, cycle furnace and check pressure drop on demand. The drop in pressure should not be more than ½" W.C. A drop of more than 1/2" would indicate a faulty regulator, a restriction in the gas l ine, or a pi nched gas line. Excessive pressure drop could also be due to moisture contamination. c. Gas pressure OK - check for obstruction in main burner; check to be sure electrode is positioned approximately 1/4" above and directly over slots on the main burner - adjust electrode if necessary.
3. The 3. The module board also performs the l ockout function in cases where the spark fails to light the burner. When lockout occurs, the spark stops, the voltage from the module board to the gas valve is discontinued, and the valve closes. The unit will remain in lockout and t he blower will continue to run until the thermostat is turned off. Turning the thermostat off disengages the lockout function of the module board. After the blower has stopped, the ignition sequence can be started again. The module will try three times for ignition before lockout.
d. Remove burner and check burner for obstructions. Clean as required. 4. Burner ignites, but goes goes off and into lockout: lockout: a. Check to be certain that flame sensor is over slots in the main burner and that the main burner flame is burning against the tip of the flame sensor - adjust by bending sensor probe. NOTE: Sensor probe should be in the inner blue cone of the burner flame (approximately 1/4" t o 5/16" above burner). b. Burner still goes off and into lockout - check wire connections at flame sensor and at module board. c. Wire connections OK - check continuity through flame sensor wire. d. Continuity of flame sensor wire OK - check with micro amp meter in series with flame sensor and flame sensor wire to be certain that the flame sensor is generating at least seven micro amps within seven seconds after the burner is ignited. Connect meter as follows: (+) to sensor wire, (-) to sensor probe. Adjust position of sensor probe, check for carbon deposits on sensor probe if reading is less than seven micro amps. e. Flame sensor circuit generating at least seven micro amps, but burner still goes off and into lockout - replace module board. 5. Repeated Repeated module board failures: failures: a. Check to be certain that the electrode spark is not sparking against the flame sensor portion of the electrode assembly. b. Check to be sure module board or high voltage wires are not shorted to the chamber wrapper or other furnace parts. c. Be sure insulator covering the electrode wire connection on the coil of the module board is in place and insulator behind module board is in place. d. Make certain that the transformer voltage is within 24 - 30 volts A.C. e. Be sure duct connections to furnace are airtight. Seal duct collar connections to furnace cabinet with duct tape, if necessary to prevent hot air leakage. No air leakage should exist anywhere in the duct system, especially at connections on furnace cabinet. f. Be sure sensor wire terminal is ti ghtly affixed to sensor probe. g. Be sure high voltage electrode wire is in good condition and properly positioned onto pierce point electrode.
29
6. Customer complains of unit going into lockout only once in a while:
f.
a. Thoroughly check electrode and burner relationship. b. Lockout can occur if the gas pressure fluctuates at the time the thermostat calls for heat. Pressure fluctuations can be caused by a malfunctioning gas bottle regulator, an obstruction or a kink in the gas line, or moisture in the gas bottle regulator or in the gas lines. It is di fficult to check for these fluctuations that will not noticeably affect any other appliance in the coach. However, isolating the furnace from the coach gas system will determine if the gas system is responsible. This i solation procedure can be done by connecting a separate upright bottle, regulator and gas line directly to the furnace, eliminating the coach gas system. If the occasional lockout still exists, then the furnace should be thoroughly tested to determine the cause; however, if the furnace works properly on this separate system, then the coach gas system should be checked. c. Check furnace return air and warm air discharge to be certain sufficient air flow is present to engage micro switch every time. d. Check micro switch to be sure it moves freely. e. Remove electrode and burner. Clean thoroughly.
When moisture in the gas system is suspected as being the problem, especially where the horizontal type gas bottle is being used, the following steps should be take to prepare the gas system against further moisture problems: Corrective Measures: 1. Disconnect gas bottle and drain it completely dry of all g as and all moisture. 2. Disconnect and blow out all gas lines completely dry. 3. Check pressure regulator on the gas bottle. Replace if necessary. 4. Add the drying agent. agent. One half pint of methanol alcohol per per 100 pound bottle capacity is recommended. Precautions: 5. Never fill the gas bottle over 80%. 6. Do not use the gas bottle completely dry to avoid using up the drying agent. We have found the above procedures to be effective in solving most occasional lockout problems, especially where the horizontal type gas bottle is used. All of these steps must be performed as described for the preparation of a contaminated gas system to be 100% effective.
Figure 21 P-30S with Time Delay
Figure 22 P-40 with Time Delay
30
Figure 23 Remote Flame Sense With Time Delay
Figure 24 Local Flame Sense (NT Models) With Time Delay
Fan Control Board Figure 25 (SF-20/25/30/35/42F)
31
Figure 26 Local Flame Sense (SF Models) With Time Delay
Figure 27 Fan Control Board (NT-12/16/20S and SE)
32
Figure 28 Fan Control Board (NT-24/30/34SP and NT-40)
Figure 29 Fan Control P-30S
33
Figure 30 Fan Control Board P-40
34
FURNACE REMOVAL To replace parts or service the SUBURBAN family SUBURBAN family of RV furnaces, it is necessary to follow these steps:
DD-17DSI 1. 2. 3. 4. 5. 6. 7. 8. 9.
Turn off gas and pow er, then disconnect gas and pow er supply at the furnace. Label wires as necessary. Remove the vent cap assembly by removing applicable screws. Rem ove the cabinet front two (2) screws. Remove the applicable screws securing the furnace to the coach floor. Remove duct from side of furnace, if equipped. Remove the furnace from the cabinet area to gain access to combustion chamber and applicable parts. Some parts can be accessed without removal of the complete furnace. To re-install, reverse this procedure. Rewire applicable wires and perform a leak test on all all fitti fittings. ngs. Perform a drop pressu re test.
NT-12/16/20S 1. 2. 3. 4. 5. 6. 7.
Turn off gas and pow er, then disconnect gas and pow er supply at the furnace. Label wires as necessary. Remove the vent cap assembly by removing applicable screws. Rem ove the cabinet front two (2) screws. Remove the (1) one tie down screw securing the chamber to the cabinet. Rem ove the furnace from the cabinet by pulling chamber outward com pletely to to gain access to all controls and applicable applicable parts. To re-install, reverse this procedure. Rewire applicable wires and perform a leak test on all all fitti fittings. ngs. Perform a drop pressu re test.
NT-12/16/20SE 1. 2. 3. 4. 5. 6. 7.
Turn off gas and pow er, then disconnect gas and pow er supply at the furnace. Label wires as necessary. Remove the vent cap assembly by removing applicable screws. Rem ove the cabinet front two (2) screws. Remove the (2) two tie down screws securing the chamber to the cabinet. Rem ove the furnace from the cabinet by pulling pulling cham ber outward com pletely to gain access to all controls and applicable applicable parts. To re-install, reverse this procedure. Rewire applicable wires and perform a leak test on all all fitti fittings. ngs. Perform a drop pressu re test.
NT-24/30/34SP NT-24/30/34SP and N T-40 1. 2. 3. 4. 5. 6. 7.
Turn off gas and pow er, then disconnect gas and pow er supply at the furnace. Label wires as necessary. Rem ove the vent cap assembly by removing applicable screws and one (1) flue retaining screw. Not applicable applicable to NT-40. Rem ove the cabinet front two (2) screws. Remove the (2) two tie down screws securing the chamber to the cabinet. Rem ove the furnace from the cabinet by pulling chamber outward com pletely to gain access to all controls controls and applicable parts. To re-install, reverse this procedure. Rewire applicable wires and perform a leak test on all all fitti fittings. ngs. Perform a drop pressu re test.
35
FURNACE REMOVAL SF-20/25/30/35/42, SFV-20/25/30/35/42, SH-35/42 and SHD-2542 1. 2. 3. 4. 5. 6.
Remove the vent cap assembly from the outside access door by removing applicable screws, also the four (4) screws retaining the door to the frame. Rem ove the door to gain access to the furnace. Turn off gas and pow er, then disconnect gas and pow er supply at the furnace. Label wires as necessary. Remove the (1) one tie down screw securing the chamber to the cabinet. Remove the furnace from the cabinet by pulling chamber outward completely to gain access to all controls and applicable parts. To re-install, reverse this procedure. Rewire applicable wires and perform a leak test on all fittings. fittings. Perform a drop pressure test.
SF-20/25/30/35/42F, SFV-20/25/30/35/42F and SH-35/42F 1. 2. 3. 4. 5. 6. 7.
Turn off gas and pow er, then disconnect gas and pow er supply at the furnace. Label wires as necessary. Remove the vent cap assembly by removing applicable screws. Rem ove the cabinet front two (2) screws. Remove the (1) one tie down screw securing the chamber to the cabinet. Rem ove the furnace from the cabinet by pulling chamber outward com pletely to to gain access to all controls and applicable applicable parts. To re-install, reverse this procedure. Rewire applicable wires and perform a leak test on all all fitti fittings. ngs. Perform a drop pressu re test.
P-30S and P-40 1. 2. 3. 4. 5. 6. 7.
Turn off gas and pow er, then disconnect gas and pow er supply at the furnace. Label wires as necessary. Remove the vent cap assembly by removing applicable screws and one (1) flue retaining screw. (Not applicable to P40.) Rem ove the cabinet front two (2) screws. Remove the (2) two tie down screw securing the chamber to the cabinet. Rem ove the furnace from the cabinet by pulling chamber outward com pletely to to gain access to all controls and applicable applicable parts. To re-install, reverse this procedure. Rewire applicable wires and perform a leak test on all all fitti fittings. ngs. Perform a drop pressu re test.
36
SF, SH AND SHD-2542 ELECTRODE GAP SPECIFICATIONS AND POSITIONING To ass ure cons istent ignition ignition of the burner, it is important for the electrode to be pos itioned properly over the top of the burner. When replacing the electrode, or should you be experiencing ignition type problems, the electrode should be positioned as outlined in the drawing. 1.
Rem ove the furnace cham ber assem bly from the furnace cabinet following following instructions listed listed in the the installation installation ma nual.
2.
Rem ove the burner acce ss door. Manifold assemb ly will will have to to be removed at the valve. Rem ove the burner from the com bustion chambe r by removing six (6) screws which attach the burner to the chamber and air baffles (plates). Remove top air baffle and c lip.
3.
Locate the lance in relation to the burner ports for electrode pos itioning itioning by: a.
Shine a flashli flashlight ght into into the burner venturi venturi as illustrat illustrated ed (be sure the flashlight flashlight lens is against against the end of the burner).
b.
Light will reflect reflect off the the lance in the venturi venturi of the the burner and shine shine through a positio position n of the two two (2) rows of burner ports in the top of the burner.
c.
Using a black black felt-ti felt-tip p pen, mark a line line along top top of burner 3/16" 3/16" from from back of lance and parallel parallel with with lance. lance. Make an additional mark indication center line of the lance. (See illustration). Both marks w ill be used later as reference mark s; therefore, keep lines thin.
4.
Reass emble the burner into the chamber. Be sure the air baffles (plates) are positioned positioned as rem oved. Mount center clip in place.
5.
Ad just ju st e lec tro de so the ele ctro ct rode de prob pr ob e is po sition sit ion ed alo ng the th e m ar ke d c en ter line of t he bu rn er lan ce an d th e tip of t he electrode terminates 3/16" from the back of the lance (at the line marked in Step 3C). (See illustration). illustration).
6.
I M P O R T A N T : Be sure electrode probe m aintains a 1/8" spark gap over the burner as illustrated.
7.
Reinstall burner access door and reconnec t manifold. Man ifold must be checked for leaks leaks with unit operating, before installing installing in cabinet. Re install furnace into the cabinet following the instructions in the installation installation ma nual. Check all gas connec tions for leaks leaks us ing proper leak test solution.
Figure 31
37
NT ELECTRODE GAP SPECIFICATIONS AND POSITIONING To ass ure cons istent ignition ignition of the burner, it is important for the electrode to be positioned properly over the top of the burner. When replacing the electrode, or should you be experiencing ignition type problems, the electrode should be positioned as outlined in the drawing.
1. 1/8" spark gap between electrode electrode and ground. 2. Maintain electrode position position of 3/16" over burner ports.
Figure 32 LOCAL FLAME SENSE
PARK MODEL ELECTRODE GAP SPECIFICATIONS AND POSITIONING To ass ure cons istent ignition ignition of the burner, it is important for the electrode to be pos itioned properly over the top of the burner. When replacing the electrode, or should you be experiencing ignition type problems, the electrode should be positioned as outlined in the drawing.
1. 1/8" spark gap between electrode electrode and ground. 2. 1/4" spark gap between ground and flame flame sensor. 3. Maintain electrode electrode position of 3/16" over burner ports. ports.
Figure 33 REMOTE FLAME SENSE
38
MAINTENANCE Preventative maintenance is ess ential ifif an RV ow ner is to have reliable, safe operation of his furnace. T wo important areas to watch closely in order to assure sa fe, reliable reliable operation are the venting and the main burner. An ob str uc tion tio n in i n the t he ve nt or m ain bu rner rn er will wil l re du ce the co m bu stion st ion air wh ich re su lts in i nc om ple te co m bu stion sti on . W he ne ve r incomplete com bustion occurs, the by-products are carbon mono xide (CO) and soot. If the furnace outside exhaust vent shows black soot forming, the furnace should not be operated until the problem is corrected. Two common causes are: 1. Restriction in the the vent or furnace intake (screens , wasp nests, tape). 2. Dirty burner. If operation of the furnace continues under these c onditions, itit could result in in serious injury to the occupants of the RV o r even death. Cleaning of the main burner and an inspe ction of the venting system should be don e at least once a year, preferably just before the beginning of the heating heating season . Some RV owne rs and service personnel have the false assum ption that if a furnace has not been used, it will not require cleaning. NOT SO! A SO! A furnace which has not been used for some time could be m ore in need of cleaning than a furnace which has been used extensively. Dust and lint should be rem oved from the room a ir blower wheel and sail switch. A build up of dust and lint on the blower wheel can cause the m otor to drag and not generate enou gh air flow to to engage the sail switch. Dust accumulation on the sail switch will restrict restrict the travel of the actuator arm to where the air flow acros s the padd le will not sail it in and com plete the valve circuit. A ye ar ly insp in sp ec tion tio n s ho uld be m ad e o f all ga sk ets on the fur na ce . If a ny g as ke ts s ho w sign s ign s o f lea ka ge or de ter ior ation ati on , the y must be replaced. replaced.
Figure 34 Figure 35
Figure 36 Figure 37
39
CAUTIONS & SAFETY INFORMATION 1.
Never use a battery charger to power or test an electronic ignition furnace as they sometimes provide more than 14.5 DC Volts that could damage the module board.
2.
Never operate the furnace with the electrode wire disconnected nor with the electrode ass embly removed from the furnace.
3.
Never use a s crewdriver on any part of the electrode assemb ly while while the furnace is in operation.
4.
Be certain that the spark from the electrode never reaches the flame sensor portion of the electrode assembly on remote sense units.
5.
Install the the furnace so electrical compo nents and conn ections are protected from water.
6.
W ire the furnace direct to to the battery when possible.
7.
Use two wrenches on gas fittings when tightening gas connections.
8.
Verify voltage voltage of furnace , do not use 120 volt AC with 12 volt DC.
9.
Do not mo dify the the furnace in any way.
10 .
Do not vent the furnace to an outside enclosed porch area or where the vent is covered or obs tructed.
11 . Alw ays m ee t o r e xc eed ee d m inim ini m um du ct requ re qu ire m en ts. Als o m ee t th e m inim ini m um retur re tur n a ir r eq uir em en ts. 12 .
Furnace m ust be installed and vented correc tly. tly. Refer to the Installation Installation Manu al for the specific model furnace .
13 .
Do not install aftermarket components.
SUBURBAN MANUFACTURING COMPANY 676 Broadway Street Dayton, Tennessee 37321 423-775-2131 Fax: 423-775-7015 www.rvcomfort.com E-mail:
[email protected] 2007
