Coleman burner wont shut off: Model-7680B Series-856

[kclarke]

Hi, I have a coleman Model 7680B Series-856,
Let me try to explain, I can light the pilot without any problems, but as I turn the control knob to on, the burner kicks on, the thermostat, and power to the blower is off: I have disconnected the two wires that go to the valve, it still keeps burning: I have replaced the thermocoupler and the thermostat: With the control knob to the on position, if I turn the power to the fan on, the fan will turn on for about 45 seconds and then shut of, and repeat continuously: I have to turn the control knob back to pilot to keep it from continuously burning.....ok, is the valve stuck, do I need to replace the unit, is there a reason it is stuck, any suggestions? Also, if I let the furnace run like this for awhile, is it dangerous, the reason, it just snowed, (not often it snows here) ...

Thank you

Kevin

[Robert]

Hi Kevin,


IF the burner is lit with the wires to gas valve disconnected, then the gas valve is bad. With wires disconnected, there is no power and furnace should not be running.


May be other issues as well though and with the cost of the gas valve and other parts, I would get an hvac tech to at least know what is wrong and needed.



Thanks,
Robert

[kclarke]

It was the valve, everything else checked out! Thanks

[Robert]

Hi,

You're very welcome, happy to help.



Take care and best wishes,
Robert