Coleman 7680B-856 Won't Stay Operational

Questions about repairs and parts for Coleman furnaces, air conditioners and heat pumps for manufactured homes. Click here for Coleman parts.

Moderators: Greg, Mark

Post Reply
jbarfoot
Posts: 2
Joined: Tue Nov 04, 2014 1:22 pm

Thu Nov 06, 2014 6:17 pm

Unit is a 1978 Coleman Furnace that has worked fine since the unit was new. This year, the pilot was lit by my tenant (I understand we probably should have left it burning) and the furnace worked for about 10 days at which time it stopped working (the pilot went out). A technician was called. He lit the pilot but it wouldn't stay lit when he let the control knob up. He changed the thermocouple and the pilot stayed on. He then turned the knob to on and the main burner came on. The unit, however, only worked for one cycle (thermostat cycled the main flame off) and the pilot went out again. This was repeated a couple more times. I (the owner) came in the next day and re-lit the pilot (noticed that it took about a minute or a bit more before it would stay on) with the thermostat set to minimum. Turned to On and raised the thermostat to max upon which the main burner came on. Cycled the thermostat a couple of times and operation seemed normal. Unit worked for about 12 hours before the pilot went out again. Since then, the pilot has been lit a few times but the unit will only work for one cycle before the pilot goes out again. Observing the pilot, it seemed strong with a large bifurcated blue flame. The main burner flame was mostly blue with some orange at the ends of the flame. It would seem that the unit is on the verge of proper operation but doesn't want to stay lit for some reason. I have a technician there right now with instruction to clean and check the unit (including the spud/orifice as you had suggested to another post) before he even lights the pilot. Hopefully, this will help. Any suggestions or ideas you may have about what might be wrong or what might help would be much appreciated.


jbarfoot
Posts: 2
Joined: Tue Nov 04, 2014 1:22 pm

Thu Nov 06, 2014 8:15 pm

Technician cleaned the unit as I understand. Lit the pilot, checked operation for normal, and left. Tenant returned after work, house was a bit cool, tried thermostat with no response, checked and pilot was out again. Not sure where to go from here.

Post Reply