Dometic DFMD20121 Less-Door Furnace Parts Guide

This DFMD20121 parts reference covers the 20K less-door configuration. It retains the vent panel, panel extension and manifold components that differ from the standard-door references.

Use the drawing callout, part description and quantity to identify the component. Select a linked manufacturer number for product details and availability, and match the furnace model and serial-number range before ordering.

Parts pictured in this guide

Select an image for product details, or jump to the numbered diagram and parts list. Match the part number and furnace model before ordering.

Atwood / Dometic 35100 Small Furnace Ignition Electrode Kit - AFMD — DFMD20121 reference 4510Atwood / Dometic 35100 Small Furnace Ignition Electrode Kit - AFMDPart 35100 · Drawing reference 4510
Atwood 31501 12V DSI Furnace Ignition Board With Fan Control — DFMD20121 reference 4541Atwood 31501 12V DSI Furnace Ignition Board With Fan ControlPart 31501 · Drawing reference 4541
Atwood 31091 190°F RV Furnace High-Limit Safety Switch — DFMD20121 reference 4560Atwood 31091 190°F RV Furnace High-Limit Safety SwitchPart 31091 · Drawing reference 4560
Dometic 36688 Atwood 2-Inch RV Furnace Duct Adapter — DFMD20121 reference 4575Dometic 36688 Atwood 2-Inch RV Furnace Duct AdapterPart 36688 · Drawing reference 4575
Atwood 31474 Aluminum 4-Inch RV Furnace Duct Collar — DFMD20121 reference 4576Atwood 31474 Aluminum 4-Inch RV Furnace Duct CollarPart 31474 · Drawing reference 4576
Dometic 31361 4-Inch RV Furnace Duct Knockout Cover Plate — DFMD20121 reference 4577Dometic 31361 4-Inch RV Furnace Duct Knockout Cover PlatePart 31361 · Drawing reference 4577
Atwood 30268 LP-Gas Furnace Burner Head — DFMD20121 reference 4581Atwood 30268 LP-Gas Furnace Burner HeadPart 30268 · Drawing reference 4581
Dometic 33050 Mojave RV Furnace Exhaust Vent Kit, 5-1/2 in — DFMD20121 reference 4705Dometic 33050 Mojave RV Furnace Exhaust Vent Kit, 5-1/2 inPart 33050 · Drawing reference 4705
Dometic 32300 Black 12V Heat-Only RV Furnace Thermostat — DFMD20121 reference 4755Dometic 32300 Black 12V Heat-Only RV Furnace ThermostatPart 32300 · Drawing reference 4755
Dometic 38453 White HFH-2000 RV Furnace Thermostat — DFMD20121 reference 4757Dometic 38453 White HFH-2000 RV Furnace ThermostatPart 38453 · Drawing reference 4757
Dometic DFMD20 Mohave furnace exploded service diagram accompanying DFMD20121 reference
DFMD20 family service illustration. Read the DFMD20121 numbered parts table for the correct configuration.

DFMD20121 original service part numbers

Reference Manufacturer part number Quantity Component description
4504 30322 1 CIRCUIT BREAKER, 7 AMP
4510 35100 1 ELECTRODE
4516 31098 1 VALVE 12VDC TOP
4524 31094 1 SAIL SWITCH-WHITE - (For S# 72489156 & Below)
4524 33063 1 SAIL SWITCH-DF-BLACK USE 33082
4524 33082 1 SAIL SWITCH
4528 33053 1 SAIL SWITCH MOUNT M-L
4541 31501 1 CIRCUIT BOARD
4548 30730 1 MOTOR 16-20
4560 31091 1 LIMIT SWITCH 190 DEG
4565 35712 1 MANIFOLD EXT ASSM
4575 36688 1 DUCT ADAPTER 2 INCH
4576 31474 1 DUCT ADAPTER 4 INCH
4577 31361 1 DUCT COVER PLATE 4 INCH
4581 30268 1 BURNER HEAD, LP GAS
4600 30829 1 ORIFICE 1.30MM LP
4610 31244 1 CASING LEG
4615 30205 1 BOTTOM ADAPTER PLATE-VERTICAL
4620 30261 1 BOTTOM ADAPTER PLATE-HORIZONTAL
4625 33126 1 BLOWER WHEEL W/CLAMP
4630 33128 1 COMBUSTION AIR WHEEL
4681 30456 1 VENT COVER PANEL USE 31367
4681 31367 1 VENT COVER PANEL V3-V4
4689 33055 1 VENT PANEL EXTENSION
4705 33050 1 DOOR VENT ASSEMBLY
4755 32300 1 WALL THERMOSTAT, HEAT ONLY BLACK
4756 38452 1 WALL THERMOSTAT, HEAT ONLY BROWN
4757 38453 1 WALL THERMOSTAT, HEAT ONLY WHITE
4848 30751 1 BLOWER HOUSING-MEDIUM
4852 32444 1 BLOWER HOUSING COVER-MEDIUM
4855 33060 1 WIRING HARNESS DC
4856 33052 1 BOARD & BREAKER BRACKET
4859 33166 1 EXHAUST ADAPTER N/R
4869 33301 1 HEAT EXCHANGER-MEDIUM

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