Coleman DGAA056BDTA Error Code 1 Flash: Ignition Failure
What Does Code 1 Flash Mean?
On the Coleman DGAA056BDTA, a single green flash reports an ignition failure detected by the Integrated Ignition Control. Each call for heat runs a fixed sequence: the board energizes the hot surface igniter for a 30-second warm-up, opens the gas valve for 10 seconds, and watches the flame sensor. If a flame is not proven within 2 seconds of the valve opening, the control shuts the gas off and starts a retry. Three failed retries in one call for heat send the furnace into a one-hour lockout before it will try again.
Because this is a single-stage, natural-gas mobile-home furnace, ignition depends on a short, simple chain: gas has to arrive at the burners, the igniter has to reach ignition temperature, and the flame sensor has to conduct enough current to tell the board a flame is present. The most common causes are no gas reaching the burners and a cracked or misaligned hot surface igniter. A dirty or oxidized flame sensor is also common — the burners may actually light, but the board never 'sees' the flame and drops the gas as a safety measure. A gas valve that does not open fully will produce the same lockout.
Code 1 can be confused with the pressure-switch faults on this same board. If the furnace also shows 3 flashes (combustion air pressure switch failed to close), the inducer/venting problem must be resolved first, because the board will never reach the ignition step. Remember not to cut power to read the code — on this control, removing power erases the stored fault from memory.
What You'll Notice
- The igniter glows but the burners either never light or light briefly and go out within a couple of seconds
- You hear the inducer and a soft click of the gas valve, but no sustained flame and no heat
- The green LED behind the blower-door view port flashes once, pauses about two seconds, then repeats
- After a few rapid attempts the furnace goes completely silent for roughly an hour (the one-hour lockout)
- Supply registers blow cool air or nothing while the thermostat still calls for heat
Common Causes
How This Is Diagnosed
A technician works the ignition chain in order. First they confirm the gas supply is on and the manual valve is open, then verify inlet and manifold gas pressure with a manometer. Next they inspect the hot surface igniter for cracks and check that it glows during the 30-second warm-up, and confirm it is aimed at the burner. If gas and igniter are good, they measure the flame sensor's microamp signal during a trial for ignition to see whether a real flame is being sensed. The gas valve and its wiring are checked last, since a valve that will not open produces the same lockout.
The order matters because each step depends on the one before it: there is no point measuring a flame signal if the burners have no gas, and no point condemning the valve before confirming the igniter actually fires.
When to Call a Professional
This code involves components that are not homeowner-serviceable, so have a licensed HVAC technician diagnose and repair it. Keep in mind:
- The furnace locks out on 1 flash and the igniter never glows red-hot during the warm-up period
- You smell gas near the furnace at any time (leave immediately and call your gas company first)
- The burners light but the flame drops out within a second or two, every cycle
- Other appliances lose gas pressure, or the gas supply to the home is interrupted
- The 1-flash lockout keeps returning after the one-hour reset
Frequently Asked Questions
Why does my Coleman DGAA056BDTA wait an hour before trying to light again?
The Integrated Ignition Control allows three ignition retries per call for heat. After the third failure it enters a one-hour lockout as a safety measure to avoid repeatedly dumping unburned gas. It will attempt ignition again automatically once the hour passes, or sooner if you cycle the thermostat off and on.
Can I fix a 1-flash ignition failure myself?
This code is rated for professional service because its likely causes — gas supply, the hot surface igniter, and the gas valve — involve gas and combustion components. A dirty flame sensor is one possible cause, but on this furnace the fault is not classified as a homeowner DIY repair, so it is safest to have a qualified HVAC technician diagnose it.
Should I turn the furnace off and on to clear the code?
You can cycle the thermostat to trigger a fresh ignition attempt, but avoid cutting power at the breaker if you still need the diagnostic code, because removing power erases the stored fault from this control's memory.
How much does it cost to repair an ignition failure?
It depends entirely on the cause and your region — a flame-sensor cleaning is minor, while a hot surface igniter or gas valve replacement costs more. Ask your technician for a diagnosis before authorizing parts, since prices vary widely by area and by which component has failed.
Sources
✓ Verified against manufacturer service manual — March 2026