Thread: Need help House furnace

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Just got home last night, to find one of our furnaces not working. We had a funeral to attend out of State. Brother in-law 62 retired military Air Force, and the US Army. He died the day after Thanksgiving and we were gone three days two nights.

When we got home I could see the temperature was just above 50 degrees, and the setting was just under 70 degrees.

First thing I checked for power at the furnace. Had power, changed the thermostat, and then put a jumper wire for the safety switch on the bottom panel.

I changed the motor last year. I’m hoping it's nothing more then a transformer. I'm going to try to find one today. The circuit board looks ok, we changed one on the other furnace this past summer when we didn't have air.

It's a Frigidaire 100,000 BTU 90% outside air combustion. I put the furnace in about 6 or 7 years ago. We have had more trouble with furnaces we moved here 15 years ago we replaced two propane furnaces, one was in the basement with rotted pipes going through the walls and out the roof. We had carbon monoxide going through the house and the only way we found out was the condensation on the windows inside, we got rid of that furnace and put an outside air combustion furnace in. We have had problems with that one also. Any help or thoughts would be appreciated.

It's cold.

Richard

check your transformer, check to see if inducer motor running, does it try to ignite?? does the igniter panel come on, turn off switch on furnace , set thermostat on about 75 turn on switch then describe what happens, i will try to help, i just need more info

give some symptoms of what it does when it tries to come on, turn off thr power to the furnace turn the t stat up to 75 or so then turn the power back on then describe what happens, does the inducer motor come on?? do you have 24 volt at the transformer? does it try to light then shut off?

I don't have any sound at all when I put power to it. I just checked power to the motor but forgot that I had the saftey switch open. I'm going to see if I have power to the motor with the switch closed.

Richard

I have power to the motor but nothing happens. I'm not sure how to check the transformer but I think I'll take a chance on buying a new one Monday, I hope it's not the motor.

Richard

Yikes Richard! I hope you resolve this soon. It's cold here, it must be freezing there!

Steve, one part of the house is warm the other part is pretty cold. It was a big shock to come home at this time of the year and have a furnace not working. I looked on youtube trying to find out how to check a transformer; I found some pretty good information on checking the transformers. I found out the hard way with the last break down there are certain wires you don't want to touch at the same time.

If I can't get it fixed by Monday I'll have to call for a repairman. I have a feeling it's the universal motor I put in last year. I had to have the guy walk me through putting different color wires together to make it work. The motor was warranted but I would have to drive to Chicago to get their replacement.

My wife said if I could make it in a tent when I was in boot camp in January I could make it now for a couple of days.

The real kicker is I just bought a 75,000 BTU unit furnace for the garage this past Monday because I was having trouble with the 100,000 BTU already there.

There are people that are having a harder time then me so I'll try not to complain.

Richard

unwire the transformer and ohm with ohm meter it should have resistance, or it should have 24-28 volts ac, does the furnace try to light, it could be the relay that is built into the board, not sending power to the blower motor, look up ignition sequence for your model the inducer blower should come on when you call for heat if that does not work and it goes off it could be the pressure switch, does the ignitor panel ever light, if it is lighting then kicking off the relay fro the blower can be bad, ohm out the blower motor, and make sure the capacitior is ok, try to start it by turning on the power and sit in front and watch what happens, the inducer fan should come on followed by a delay. the ignitor will light , the gas valve will open, if it shuts down down right away , it could be the flame sensor i hope this helps,

Originally Posted by simpsongreg68

unwire the transformer and ohm with ohm meter it should have resistance, or it should have 24-28 volts ac, does the furnace try to light, it could be the relay that is built into the board, not sending power to the blower motor, look up ignition sequence for your model the inducer blower should come on when you call for heat if that does not work and it goes off it could be the pressure switch, does the ignitor panel ever light, if it is lighting then kicking off the relay fro the blower can be bad, ohm out the blower motor, and make sure the capacitior is ok, try to start it by turning on the power and sit in front and watch what happens, the inducer fan should come on followed by a delay. the ignitor will light , the gas valve will open, if it shuts down down right away , it could be the flame sensor i hope this helps,

I am pretty much limited to changing parts but I don’t know which ones. I called about a transformer but I can’t get it until Monday. The furnace will not do anything, I switched the thermostat but since it quit when we were gone something could have burnt out. I have had frost get on the air intake an the furnace would not light, the inducer was trying to pull air but since it was blocked with frost it couldn't, and the inducer motor would run until I cleared the frost. When we left for the funeral it was raining then it got really cold so without being at home I'm thinking that could have been the problem? I just feel better when I know what the problem is. I'm not too good at troubleshooting.

Thanks for your help, I will go at it again tomorrow but I think it's going to be more then I can fix this time.

When the motor went out last year, and I had to get a universal one until the guy had me hook up the right wires even though they were different color the furnace acted like it is now so it may be another motor. The replacement motor was not the same speed as the original, I think we had a three speed and the new replacement was a two speed but it worked when he had me to hook up the right wires.

Richard

Hello, I've checked transformers before with an insulated screwdriver, holding it approx. 1/8" from the contacts, (very high voltage,so be carefull). The burner has to first kick in, after the reset buttom is reset, but if it's not rolling over, it's not likely to be the transformer. Of couse this works for oil fired burners we have down here in cold eastern Canada, not sure if you folks have the same there.
Sure hope you get it working, though, cause it's cold everywhere lately!~
Good Luck,Brian

Originally Posted by Oldmanb

Hello, I've checked transformers before with an insulated screwdriver, holding it approx. 1/8" from the contacts, (very high voltage,so be carefull). The burner has to first kick in, after the reset buttom is reset, but if it's not rolling over, it's not likely to be the transformer. Of couse this works for oil fired burners we have down here in cold eastern Canada, not sure if you folks have the same there.
Sure hope you get it working, though, cause it's cold everywhere lately!~
Good Luck,Brian

I found out that the small transformer has a hot side on the other furnace. I lost the tip of my multi tester probe while checking the switch on this furnace! The furnace is acting like it did when the motor went out. I had a bad circuit board on the other furnace but it made sounds where this one does nothing. I think from you talking about the transformer not doing anything until you get ignition I’m thinking it’s another motor. We have propane here, we have to convert from natural gas.

Thanks for your help. The last time I checked it was 21 degrees and falling.

Richard

Hello Richard, Any luck with your furnace?
Brian

Originally Posted by Oldmanb

Hello Richard, Any luck with your furnace?
Brian

Brian, I put a new motor in today but It still didn't work. I bought a new thermostat at the wholesale supply store also, when the new motor didn't work I started putting the new thermostat in but realized they gave me the wrong base. I will have to change it tomorrow. I've got over two hundred in it so far, if I can't get it by tomorrow evening I'll have to give up and call a repair man. I hate to give up so I try pretty hard but sometimes it's more then I can handle.

If I wasn't 63 I would take a course in heating and air conditioning.

Thanks for asking.

Richard

Richard. you've already done more than I could! Good luck and keep us posted

Thanks Steve, I hate to say Uncle. To top off the wrong thermostat the guy charged me $70 I just wrote a check not thinking about what it cost. I checked this morning and Lowe's has the one I need for $39.95 So much for the wholesale supply store.

It's like working on a car when it goes right it's a great feeling but when it doesn't it's a bummer.

Richard