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My furnace will not stop running and its blowing cold air.
Does the furnace operate? If not, look inside blower compartment and see diagnostic light count the blinks and look on door for a chart that tell you the problem. Do this and get back to me.
Furnace operates solid green. Don't see a chart.
An open limit switch would cause the fan to all the time but you said the furnace operates and heats ok. Is the fan set to auto on the tstat.? If it is set to auto pull the cover off tstat to see if fans shuts down. If fan shuts down bad tstat, if not possible bad furnace board.
Furnace does not heat. When we hold the black button in the furnace, goes right on but does nothing but blow cold air and doesn't shut off. CanI call you? We have a new-born in the house and it is winter. NY. The power light and the ok light stay solid green and do not flash. All I did was turn the temp up and the furnace just went straight to the blower and it keeps running. Removed thermostat and furnace keeps running and blowing cold air.
Does the induced draft fan come on at all? If the induced draft fan does not go on,open blower compartment and jumper between r and w. There will be a door switch so you have to have someone hold that in for you while you jumper. If furnace comes on and heats, bad tstat. Check this next I’m right to get back to you quick now.
That did not work, both blowers turn on at the same time.
Do you have a volt meter? If you do, when the induced draft fan starts, go across the contacts on the air switch to see if you get voltage. Also the tstat does bring on the induced draft fan correct. If the switch is made. Let the unit run and check voltage across limit switch that is located above burners. If one of them is open you will have 24 volts across them. Get back with me I am right here.
I don't have a voltage meter.
There is only so far you can go without test equipment. You need to call a service tech. You have more than one problem with this unit.
If I can locate a voltage meter and do what you ask, if I get 24 volts then what do I do?
If you have 24 volts across the draft switch and the fan runs bad switch. If you don’t have voltage across, touch one terminal of the switch and the other lead to ground, if voltage is present switch is ok. If fan is running and you know switch is bad,jumper switch and see if furnace fires. But only leave it jumpered till you have heat. If switch is ok go to limit and do the same checkThese checks have to be done with the furnace running or calling for heat. Also check to see if there are any rollout switches with manual resets. They would be near the entrance to the burner.
I can't get a friend over here until 8:00 am.If I have them do this, can I get back to you with my findings.
No problem glad to help you.