Coleman 7655-856 flameout

[dond]

New forum member here.

Worked fine all day yesterday, first lighting in a few years. For some reason previous owner had gas service disconnected.

Today....
Pilot lights, stays lit, call for heat, burner lights, burns for 10 sec..20 sec..sometimes long enough to trigger blower...click..gas valve shuts off, including pilot.

?

TIA

[Robert]

Hi Don,

Could be a few different reasons or a combo. If it has been disconnected and not used for awhile, best to have it cleaned, serviced and inspected by a HVAC Tech for safety.


Could be gas pressure problem, orifice clogged, roof-jack damaged or clogged, burner clogged, heat exchanger problem, etc... .



Thanks,
Robert

[dond]

Thanks for the prompt reply Robert.
I thought it was kind of odd that after the hiatus, the furnace performed fine all day and into the night. I lowered the temp and went to bed last night, waking to a cold house. I re-lit and it worked for about an hour, running steadily when it shut down. Repeated attempts to re-start have resulted in the behavior I described.
I just pulled the valve, checked the orifice, the "defuser" at the business end of the burner did have some material in the "flutes" and I cleaned them.
As a layperson, because the furnace suddenly stopped, I thought maybe a switch had failed.

Thanks again Robert.

[Robert]

Hi Don,


Is gas valve still receiving 24-28 vac at time it quits ?



Robert

[dond]

Robert, I was just sitting in front of my furnace watching the burner in action. I cleaned the viewport to see better. The pilot flame is quite small and when the burner lights, the burner flame really doesn't touch the thermocouple and it seems to draw the pilot flame away from the 'couple.
I adjusted the pilot flame to about 1 to 1-1/4" , called for heat and it's been running for about 15 min now and putting out heat.
Watching the burner action now, the pilot flame is strong enough to stay in contact with the 'couple.
Comments?


BTW this unit has no filter in the cover and if I am able keep her going I will need the correct filter and hdwe.

[Robert]

Hi Don,

Did you clean and check pilot burner,orifice and tube ?

If they are clean as well, just be sure pilot flame covers top 1/2" to 3/4" fo thermocouple.

That may have been the problem as that is a must.


Your furnace filter and filter clips can be seen and ordered through

PayPal from this page:

http://www.mobilehomerepair.com/ColemanFilters.html


Hopefully you have a good CO monitor ot two or three in home, if not please get them as well.

If you have any more problems , give us a holler.


Thanks for inquiring,
Robert

[dond]

Also while looking at the flame I saw no red glow at the thermocouple tip so I installed a new thermocouple, adjusted the pilot to proper length and it's been working flawlessly since.

I do have a Nighthawk on duty always.
Thanks Robert.

Warm in Central AZ:

[Robert]

Hi Don,

Thanks for update and that is great, glad to hear it.


As always, you're very welcome, happy we could help some.



Take care and best wishes,
Robert