Continuos blink of green led on Coleman gas furnace

[waircon]

Hello,
I am trying to diagnose a problem with a Coleman Lp furnace Mod. # DGAT056BOD Ser. # 951069.

Boards green led blinks continuosly.

Upon interupting power the board resets, hot surface igniter heat up, valve opens, burner has orange flame, burner stays lit for about a minute, then valve closes, a minute later the unit starts sequence again, does this approximately three times and then locks out and led blink continuosly. There is no indication on the schematic for what a continuos blink is.

One thing for sure is the limit switches top and bottom are not opening and causing the problem.

Your help is deeply appreciated,
Phil

[Robert]

Hi,

Check main burner orifice for blockage (spider-web-eggs) and roof-jack/flue for damage or separation of pipes.


The diagnostic light should have a slight pause between a certain number of blinks to indicate the problem area.



Thanks,
Robert