Keep your Coleman DGAA077BDTA downflow gas furnace operating dependably with genuine OEM replacement parts from Repair Clinic. The DGAA077BDTA is a 77,000 BTU downflow gas furnace engineered exclusively for manufactured and mobile home installations under HUD safety standards. Coleman is a Nordyne brand channel product, and the DGAA077BDTA shares its manufacturing platform with Nordyne downflow manufactured home furnace components; many parts are interchangeable between Coleman and Nordyne designations at the same BTU and configuration. The related DGAX077BDTA also shares many of these parts. Parts most commonly required include the inducer booster assembly, hot surface igniter, pressure switch, flame sensor, and upper manual reset limit switch. Use the DGAA077BDTA parts list and browse the full Nordyne furnace parts catalog.
Servicing the Downflow Design of the Coleman DGAA077BDTA: HUD Manufactured Home Standards and Orientation-Specific Service
The DGAA077BDTA draws return air in at the top of the cabinet and discharges warm air downward into the subfloor duct system, the reverse of standard upflow residential furnaces. This orientation changes how nearly every component is accessed during service and affects how condensate, pressure hose routing, and the inducer assembly interact. Moisture from combustion gases accumulates in the inducer housing and pressure hose more readily in this orientation. The DGAA in the model number identifies this as a Coleman downflow gas furnace for manufactured home installation; the 077 indicates 77,000 BTU input. For downflow-specific diagnosis, visit the Coleman furnace troubleshooting section.
Most Replaced Parts on the Coleman DGAA077BDTA
Draft Inducer Booster Assembly (232325) for the DGAA077BDTA
The DGAA077BDTA inducer is listed as booster assembly 232325, including the motor, housing, blower wheel, and gasket; the OEM motor number is S1-37319801821. On units with serial numbers lower than 001207164, the replacement motor also requires the motor mount assembly 373-19806-100 if the new motor has an integral flex-arm mount. Grinding at startup in the downflow orientation is accelerated by moisture exposure to the bearing from condensate collecting near the housing. Browse Nordyne furnace inducer motor parts.
Hot Surface Igniter (232280) for the DGAA077BDTA
Coleman part 232280 is the Norton HSI hot surface igniter for the DGAA077BDTA. In the downflow orientation, the burner box is at the top of the cabinet and accessed via the upper access panel after disconnecting power and gas. The igniter is the first component to test on a no-heat call; a cracked element causes the furnace to cycle through the ignition attempt and lock out without the gas valve ever activating. Browse Nordyne furnace igniter parts.
Pressure Switch (232272) and Hose Routing Inspection
On the DGAA077BDTA, the pressure hose runs through a confined space in the downflow cabinet that is prone to kinking, especially if insulation has been disturbed during previous service. Before replacing switch 232272, inspect the entire hose length for blockage, kinks, or cracks. A clear, intact hose with a switch that still reads open at normal operating draft confirms the switch diaphragm has failed and requires replacement.
Upper Manual Reset Limit Switch (S1-02535358000)
The upper limit switch on the DGAA077BDTA is a manual reset type requiring a physical button press after it trips and the furnace cools down. A tripped manual reset limit should always prompt inspection of the blower motor, air filter, and all return and supply registers in the mobile home before the switch is reset, since the root cause must be resolved to prevent immediate repeat trips.
Flame Sensor and Gas Valve (232228)
The flame sensor rod in the DGAA077BDTA accumulates oxidation buildup over multiple heating seasons, reducing the micro-amp signal below the control board’s detection threshold. Annual light cleaning extends sensor service life. The gas valve 232228 should only be diagnosed after confirming the igniter, flame sensor, pressure switch, and limit switch are all functioning correctly, since each must be satisfied before the valve receives an open command. Browse Nordyne furnace flame sensor parts.
Coleman DGAA077BDTA Parts at Repair Clinic
- Genuine Coleman OEM Parts for the DGAA077BDTA Downflow Manufactured Home Platform: Inducer assembly 232325, igniter 232280, pressure switch 232272, and gas valve 232228 confirmed for this model. Browse the full Nordyne furnace parts catalog.
- Downflow Orientation Service Notes: Serial number break for motor mount requirement, pressure hose routing inspection, and manual reset limit procedures are documented in the catalog.
- DGAA077BDTA, DGAA077BDTB, and DGAX077BDTA Coverage: Parts for the BDTB revision and the DGAX077BDTA are also available with model-specific filtering.
- 365-Day Returns and Fast Shipping: All DGAA077BDTA parts ship promptly. The Coleman furnace troubleshooting section covers downflow-specific fault scenarios.
Coleman DGAA077BDTA Furnace Parts FAQ
What is the inducer motor part number for the Coleman DGAA077BDTA?
The draft inducer for the DGAA077BDTA is booster assembly 232325, which includes the motor, housing, and wheel. The OEM replacement motor cross-references to S1-37319801821. On DGAA units with serial numbers lower than 001207164, replacing the motor also requires the motor mount assembly 373-19806-100 if the replacement motor has an integral flex-arm mount.
What does the DGAA in the Coleman DGAA077BDTA model number mean?
The DGAA designation identifies this as a Coleman downflow gas furnace designed for manufactured and mobile home installation under HUD construction and safety standards. The 077 indicates 77,000 BTU input capacity. Downflow operation means the furnace draws return air from the top, heats it, and delivers warm air downward into the subfloor duct system, the reverse of a standard upflow residential furnace.
Why does my Coleman DGAA077BDTA pressure switch keep tripping?
On the DGAA077BDTA, pressure switch lockouts are most often caused by a blocked or kinked pressure hose between the inducer housing and the switch port. The hose routing in the downflow orientation makes it prone to condensate accumulation and kinking behind insulation. Check the hose for blockage and integrity before testing or replacing the pressure switch 232272 or the inducer assembly.
Are Coleman DGAA077BDTA and DGAA077BDTB parts the same?
The BDTA and BDTB are sequential production revisions of the same downflow platform, and many parts are shared including the igniter, pressure switch, and flame sensor. The control board and some limit switch specifications were updated between revisions; always confirm the full model designation including the revision suffix from your data plate before ordering a control board to ensure the correct version.
