Suburban Sf Series SF20FQ Parts Diagram · Replacement

Furnace · 4 assemblies · 8 diagram sheets · 71 parts · by Andrew Strick, mobile RV technician

OEM exploded parts diagrams for the Suburban Sf Series SF20FQ RV furnace: 4 assemblies (Replacement, Exploded View › Burner Assembly, Exploded View › Combustion Chamber, Exploded View › Cabinet Assembly) and 71 manufacturer part numbers. 11 parts are marked as superseded — the description gives the replacement number to order instead.

The rating plate is on the furnace chassis — slide the unit's front panel off or look just inside the exterior access door. Suburban models (SF-30F, NT-34SP …) changed burners and boards over the years, so the serial number's date range matters as much as the model.

Replacement

Components

9 items

1. #DOOR SF RV FURNACE 1 PK MFR # 6258AEB
2. #Furnace; SF-FQ Series; LP Gas; Model Number SF-20FQ; 20000 BTU; Maximum Ducted; 7-1/2 Inch Height x 17 Inch Width x 20 Inch Depth; Automatic Direct Spark Ignition; Do Not Require Exterior Access Doors; Pack Of 10 MFR # 2551J
3. #Furnace; SF-FQ Series; LP Gas; Model Number SF-20FQ; 20000 BTU; Maximum Ducted; 7-1/2 Inch Height x 17 Inch Width x 20 Inch Depth; Automatic Direct Spark Ignition; Do Not Require Exterior Access Doors MFR # 2511A
4. #RP-20 FURNACE CORE FQ MFR # 2606A
5. #Furnace; SF-FQ Series; LP Gas; Model Number SF-20FQA For Australian Market; 20000 BTU; Two Stage; Side/ Bottom Duct Discharge; 7 Amp Draw; 7-1/2 Inch Height x 17 Inch Width x 20 Inch Depth; 29 Pounds; Direct Spark Ignition; Do Not Require Exterior Access Door MFR # 2465A
6. #OPTIONAL ACCESS DOOR C/W MFR # 6258ACW
7. #Furnace; SF-FQ Series; LP Gas; Model Number SF-20FQ; 20000 BTU; Maximum Ducted; 7-1/2 Inch Height x 17 Inch Width x 20 Inch Depth; Automatic Direct Spark Ignition; Do Not Require Exterior Access Doors; Also Use New Number 2511A MFR # 2389A Superseded: see description
8. #Furnace; SF-FQ Series; LP Gas; Model Number SF-20FQ; 20000 BTU; Maximum Ducted; 7-1/2 Inch Height x 17 Inch Width x 20 Inch Depth; Automatic Direct Spark Ignition; Do Not Require Exterior Access Doors MFR # 2551A
9. #OPTIONAL ACCESS DOOR P/W MFR # 6258APW

Exploded View › Burner Assembly

Components

20 items

1. #Furnace Manifold; For Suburban Furnace SF-20/ SF-25/ SF-30/ SF-35/ SF-42/ SFV-20/ SFV-25/ SFV-30/ SFV-35/ SFV-42; With Furnace Manifold Outlet Tube And Orifice Holder MFR # 171743
2. #APPLIANCE COMPONENTS RV; Orifice Sf20 Furnace MFR # 180305
3. #Furnace Gasket; Furnace Burner Access Door Gasket; Fits Suburban Furnace SF-20/ SF-25/ SF-30/ SF-35/ SF-42/ SFV-20/ SFV-25/ SFV-30/ SFV-35/ SFV-42; Also Use New Number 525031 MFR # 71263S Superseded: see description
4. #APPLIANCE COMPONENTS RV; Tinnerman U Type MFR # 121704
5. #APPLIANCE COMPONENTS RV; Plate Sec Air MFR # 63198
6. #APPLIANCE COMPONENTS RV; Screw 8-18 X 1/2 Ph Ph MFR # 121651
7. #APPLIANCE COMPONENTS RV; Plate Sec Air MFR # 62933
8. #Furnace Duct Cover Plate; Fits Suburban SF-Series Furnace MFR # 62935
9. #Igniter Electrode; For Suburban Furnace Models SF-20/ SF-25/ SF-30/ SF-35/ SF-42/ SF-20F/ SF-25F/ SF-30F/ SF-35F/ SF-42F (Above Serial Number 934701426); Without Gasket; Also Use New Number 525009MC MFR # 232286MC Superseded: see description
10. #Igniter Electrode; For Suburban Furnace SF-20/ SF-25/ SF-30/ SF-35/ SF-42/ SF-20F/ SF-25F/ SF-30F/ SF-35F/ SF-42F (Above Serial Number 934701426); Without Gasket; Also Use New Number 525009 MFR # 232286 Superseded: see description
11. #Igniter Electrode; For SF20/ 25/ 30/35Q/ SF20/ 25/ 30/ 35FQ Furnace Models; Single Electrode MFR # 233222
12. #Furnace Burner; For Suburban SF-20/ SF-20F/ SF-20Q/ SF-20FQ MFR # 10767
13. #GROMMET USE 71020 MFR # 70963 Superseded: see description
14. #APPLIANCE COMPONENTS RV; Grommet MFR # 71020
15. #SUBURBAN GAS VALVE MFR # 161133
16. #APPLIANCE COMPONENTS RV; Gas Valve MFR # 161070
17. #Furnace Gas Valve; For Use With Suburban Furnace SF-20/ SF-25/ SF-30/ SF-35/ SF-42 With Serial Numbers After 971303163; Also Use New Number 525044 MFR # 161122 Superseded: see description
18. #Furnace Gas Inlet Pipe; For Use With Suburban Furnaces SF35FQ/ SFV20FQ/ SF30F MFR # 171576 Superseded: see description
19. #Water Heater Gas Inlet Elbow; For Suburban Water Heater SW4-D; 90 Degree; Also Use New Number 525025 MFR # 170374 Superseded: see description
20. #Water Heater Gas Inlet Elbow; For Suburban Water Heater SW4-D; 90 Degree; 3/8 Inch; Single MFR # 525025

Exploded View › Combustion Chamber

Components

36 items

1. #SUBURBAN VENT/EXHAUST TUB MFR # 260553
2. #1/2BX1/2B STR STOP VALVE MFR # 51249
3. #TUBE INTAKE MFR # 051447
4. #SUBURBAN AIR COMB HOUSING MFR # 390852
5. #APPLIANCE COMPONENTS RV; Screw 8-18 X 2-1/4 Ph Ph MFR # 121929
6. #Furnace Combustion Air Housing; For Suburban 3 Inch Furnace Motor SF-20/ SF-20F (Above Serial Number 102205202); Rear Half MFR # 390849
7. #Furnace Combustion Wheel; For Suburban Furnace SF-20/ SFV-20 Series MFR # 350189
8. #SUBURBAN GASKET/FARWALL B MFR # 71084
9. #SUBURBAN MOTOR MFR # 233004
10. #SCREW #4-20 X 5/8" MFR # 121945
11. #HSG ROOM AIR/BAFFLE MFR # 391039
12. #SCREW 8-18X1/2 SELF DRILL MFR # 121857
13. #HSG REAR HALF MFR # 391035
14. #Furnace Low Air Flow Switch; For Suburban Furnace SF-20/ SF-25/ SF-30/ SF-35/ SF-42/ SF-20F/ SF-25F/ SF-30F/ SF-35F/ SF-42F MFR # 232261
15. #Furnace Low Air Flow Switch; For Suburban SF20/ 25/ 30/ 35/ 42 And SF20F/ 25F/ 30F/ 35F/ 42F Series Furnaces; Also Use New Number 525003 MFR # 233382 Superseded: see description
16. #Furnace Fan Switch; For All V-Series Suburban Furnaces (After Serial Number 952202951) MFR # 232351
17. #APPLIANCE COMPONENTS RV; BRKT ON/OFF SW MFR # 63446
18. #ignition Control Circuit Board; Replacement For Suburban 520741 Or 520820 Boards And Fits All Suburban 12 Volt Furnaces; Will Not Replace 24 Volt AC Boards MFR # 521099
19. #Ignition Control Circuit Board - Fits Suburban Water Heaters MFR # 520820MC
20. #Ignition Control Circuit Board; For Suburban Furnace Models SF-20QT/ SF-25QT/ SF-30QT/ SF-35QT/ SF-42QT/ SF-20FQT/ SF-25FQT/ SF-30FQT/ SF-35FQT/ SF-42FQT/ SFV-20QT/ SFV-25QT/ SFV-30QT/ SFV-35QT/ SFV-42QT/ SFV-20FQT/ SFV-25FQT/ SFV-30FQT/ SFV-35FQT/ SFV-42FQT/ SF-20VHQT/ SF-25VHQT/ SF-30VHQT/ SF-35VHQT/ SF-20VHFQT/ SF-25VHFQT/ SF-30VHFQT/ SF-35VHFQT/ SF-T Replacement Cores; With 521099 Board And Rewiring Instructions MFR # 521314
21. #Ignition Control Circuit Board;;Replaces Dinosaurs Earlier Small And Large Fan Boards; Can Also Be MFR # DNRFAN50PLUSPINS
22. #ignition Control Circuit Board; Replacement For Suburban Furnace SF-Series (After Serial Number 003805481); 12 Volt DC MFR # 520820
23. #APPLIANCE COMPONENTS RV; Insul Cap MFR # 70973
24. #WHEEL ROOM AIR MFR # 350206
25. #APPLIANCE COMPONENTS RV; Bushing MFR # 70362
26. #APPLIANCE COMPONENTS RV; BUSHING STRAIN RELIEF 1/2 MFR # 71206
27. #GASKET,FIREWALL (CHAMBER SIDE) MFR # 71262S
28. #DISPLAY - RV; CHAMBER MFR # 21225BK
29. #SUBURBAN LIMIT SWITCH MFR # 232503
30. #SWITCH MFR # 232503MC
31. #FIREWALL MFR # 110792
32. #APPLIANCE COMPONENTS RV; SCREW 6-19 X 3/4 PH MFR # 122001
33. #APPLIANCE COMPONENTS RV; STOP MOD BOARD MFR # 63610
34. #BRACKET, ROOM AIR HOUSING MFR # 63616S
35. #Furnace Time Delay Relay; Use With Non-Fan Controlled Circuit Board 521303; For Suburban Furnace Models SF-20Q/ SF-25Q/ SF-30Q/ SF-35Q/ SF-42Q/ SF-20FQ/ SF-25FQ/ SF-30FQ/ SF-35FQ/ SF-42FQ/ SFV-20Q/ SFV-25Q/ SFV-30Q/ SFV-35Q/ SFV-42Q/ SFV-20FQ/ SFV-25FQ/ SFV-30FQ/ SFV-35FQ/ SFV-42FQ/ SF-20VHQ/ SF-25VHQ/ SF-30VHQ/ SF-35VHQ/ SF-20VHFQ/ SF-25VHFQ/ SF-30VHFQ/ SF-35VHFQ/ SF Replacement Cores; 12 Volt DC; Also Use New Number 521313 For NT-T Series Or 521314 For SF-T Series MFR # 521304 Superseded: see description
36. #Ignition Control Circuit Board; For Suburban Furnace Models With A Non-Fan Controlled Module Board: NT-16SQ/ NT-20SQ/ NT-16SEQ/ NT-20SEQ/ NT Replacement Cores/ SF-20Q/ SF-25Q/ SF-30Q/ SF-35Q/ SF-42Q/ SF-20FQ/ SF-25FQ/ SF-30FQ/ SF-35FQ/ SF-42FQ/ SFV-20Q/ SFV-25Q/ SFV-30Q/ SFV-35Q/ SFV-42Q/ SFV-20FQ/ SFV-25FQ/ SFV-30FQ/ SFV-35FQ/ SFV-42FQ/ SF-20VHQ/ SF-25VHQ/ SF-30VHQ/ SF-35VHQ/ SF-20VHFQ/ SF-25VHFQ/ SF-30VHFQ/ SF-35VHFQ/ SF Replacement Cores; Use With Time Delay Relay 521304; Also Use New Number 521313 For NT-T Series Or 521314 For SF-T Series MFR # 521303 Superseded: see description

Exploded View › Cabinet Assembly

Components

6 items

1. #APPLIANCE COMPONENTS RV; CAB FRONT 2 DUCT MFR # 102316
2. #Wall Thermostat; Single Stage; For Heat Control; Mechanical Readout; White Case MFR # 161154
3. #Wall Thermostat; Heat; Not Programmable; Mechanical Readout; Black MFR # 161210
4. #Warning Label; Replacement For Suburban SF-20Q/ SF-25Q/ SF-30Q/ SF-20FQ/ SF-25FQ/ SF-30FQ Model Furnaces MFR # 102327
5. #Furnace Duct Cover Plate; Fits Suburban 4 Inch Duct MFR # 50733
6. #NR627947 RETAINER-PANEL-12 UPR-BLK MFR # 50715