DGAA077BDT 5 flashing lights

[txMark]

Hi,
I recently put in a coleman furnace and after putting on the proper roof jack have had NO problems. Then out of the blue last night, we noticed it was blowing cold air. After looking at it, the flame lights then goes out and I get 5 flashing lights. Does anyone have a clue what could have caused this? In fact before going to bed it was perfect. Any where to start?

MANY thanks.

Mark

[Greg]

My guess is that it is something simple, however since I am not up on them I will not even try to guess. Are you using gas or oil, that will make a difference aas to what direction we send you. Greg

[Robert]

Is your furnace model a BDTA or BDTB ?



Thanks,
Robert

[txMark]

It appears to be a B. Someone told me it could be because im using CAT 3 wire for the thermostat instead of the same gauge, but would that cause it to work fine for this long then do this. UPDATE: It just started working like it should once we turned it back on after a few hours...I will watch it closely.

Thanks

mark

[txMark]

Hey guys it just started doing it again, came on like it should, then next thing you know it cycles, lights then when the blower comes on it goes right out. Same 5 lights. Last time I turned it off and waited, luckily it just started working. Any ideas?

Thanks!

[Robert]

Hi Mark,

5 flashes for your furnace indicates gas flow WITHOUT a call for heat.


Need to thoroughly inspect and check the gas valve and the gas valve wiring.


Most likely an intermittant short in there somewhere.



Take care and best wishes,
Robert