Coleman model # 7670B856 Not heating

[racohoon]

I am trying to get this furnace working. When the pilot is lit and valve is "on" thermostat set at 75 degrees or more to heat; the burner ignites and furnace works good for 1 cycle or heating. Then will not ignite burner and cycle again. I have to turn thermostat down to lowest setting and turn it back up a while later, usually half an hour or so; then it will ignite and operate 1 cycle only. I replaced the thermostat yesterday--now it will not ignite the burner or cycle at all, even if I install old thermostat. I have checked the thermo coupler by leaving valve "on" and blowing the pilot out, the valve clicks after 60 seconds or more; so it appears to be ok.

Is it the gas valve or possibly the burner? Burner looked and sounded good during operation. It just would not cycle more than once when it was operating the other day. Now won't ignite burner at all. There is an audible click at the valve ass'y. when the thermostat is set to demand heat. I have noticed several sites reference the burner is no longer available for the 856 model Coleman--any truth to this? Time to invest in a new furnace????

[Robert]

Hi,

Have been and still am away on vacation, please let me know if you still need help.



Thanks,
Robert

[pendawg]

I am having the exact same problem. I can't afford a serviceman but I thought if I even knew what part too get it would be a start. Mine has a brand new gas valve on it so I don't think its the thermocouple. If you find out anything can you let me know and I will you if I do. Thank You
Pendawg

[Robert]

Hi Pendawg,

Please start a new thread with your problem and questions. We try to keep one poster/problem per thread for ease of following.


Thanks,
Robert