Coleman DGAA056BDTA Error Code 2 Flashes: Combustion Air Pressure Switch Closed
What Does Code 2 Flashes Mean?
A 2-flash code on the Coleman DGAA056BDTA means the normally-open combustion air pressure switch contacts are stuck in the closed position. At the beginning of each heating cycle, the integrated ignition control checks that this switch is open before starting the inducer motor. If the switch is already closed, the control will not proceed with the ignition sequence.
The pressure switch is a safety device that verifies the inducer motor is creating proper draft for venting combustion gases. Its contacts should be open when the inducer is off and close only when sufficient suction is present. When the contacts are stuck closed, the control board cannot distinguish between the inducer running and not running, so it halts operation as a safety precaution.
This condition typically indicates the pressure switch has failed internally — the contacts have welded together or the diaphragm is damaged — or there is a wiring problem that is completing the circuit through the switch regardless of its actual state. A technician needs to test the switch, check the wiring, and replace the faulty component.
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Pressure switch contacts stuck closed | Most common | ✗ Call a pro → |
| Mis-wiring of pressure switch circuit | Common | ✗ Call a pro → |
When to Call a Professional
Contact a licensed HVAC technician if:
- When this code appears — a stuck pressure switch requires professional testing and replacement
✓ Verified against manufacturer service manual — March 2026