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gotoman for ac
gotoman for ac, HVAC Technician
Category: HVAC
Satisfied Customers: 4999
Experience:  51 years of experience install design and repair of all makes and models of AC
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my furnace will not stop running and its blowing cold air

Customer Question

my furnace will not stop running and its blowing cold air
Submitted: 6 years ago.
Category: HVAC
Expert:  gotoman for ac replied 6 years ago.
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. Rus
Customer: replied 6 years ago.
furnace operates solid green don't see a chart
Expert:  gotoman for ac replied 6 years ago.
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 cover off tstat to see if fans shuts down. If fan shuts down bad tstat if not possible bad furnace board. Rus
Customer: replied 6 years ago.
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. can i call you? we have a newborn 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 lowing cold air
Expert:  gotoman for ac replied 6 years ago.

Does the induced fraft 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 Im right to get back to you quick now. Rus

Customer: replied 6 years ago.
that did not work, both blowers turn on at the same time
Expert:  gotoman for ac replied 6 years ago.

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

Customer: replied 6 years ago.
i don't have a voltage meter
Expert:  gotoman for ac replied 6 years ago.

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.

Customer: replied 6 years ago.
if i can locate a voltage meter and do what you ask, if i get 24 volts then what do i do
Expert:  gotoman for ac replied 6 years ago.
If you have 24 volts across the draft switch and the fan runs bad switch. If you dont 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 check, These 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 intrance to theburner. Rus
Customer: replied 6 years ago.
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
Expert:  gotoman for ac replied 6 years ago.
No problem glad to help Rus

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