Furnace flame out after few seconds

[tommy_z]

I'm giving my Dometic furnace a shake down and find that it shuts off prematurely.

Blower comes on, I get ignition, I hear the flame for a few seconds, then the flame goes out. I confirmed HOT air at the exterior exhaust vent while briefly running. 3 tries and it's done.

Propane is full. Running on shore power. No other issues.

Can't get to the board to see the code LED without removing unit. Thought I'd try ya'll first.

[sourdough]

When I had that exact same problem I had to replace the control board I believe. Others have spoken to the issue so hopefully they will chime in.

If you are in dire straights I could power down the unit and it would ignite and run if I recall but once it shut down it would go through the 3 ignitions, ignite, blow stop.

[tommy_z]

Since the unit is so serviceable (sarcasm), I decided to keep cycling it about 10 times, and it finally started working right. I think disconnecting the lines to the tank might have allowed air in. Or I wonder if there is a small leak.

[chuckster57]

The igniter/ flame sensor may have been the issue. Hope it keeps working :)

[liv42day777]

I had the same during spring camping. I finally decided to pull the burner unit and discovered the burner screen covered with rust and debris which prevented the flame from striking the flame sensor. The burner screen is made out of stainless steel and was easy to clean with a wire brush and should be considered as part of your annual maintenance. My furnace has been working great since the cleaning.