AC will not shut off

Questions about repairs and parts for other brands of furnaces and air conditioners. Please note that our speciality is Coleman and Nordyne products, so our knowledge of other brands may be limited.

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Otis Campbell
Posts: 3
Joined: Fri Jul 31, 2009 4:28 pm

I've searched the forum & found several threads with similar problems but they weren't the same unit as mine. I've got an Intertherm FEH-020HA-04 and the AC (fan & outside unit) won't turn off unless I use the switch on the unit to turn it off. Nothing had been changed & it just started doing it out of the blue.

I can turn the thermostat way up above the room temperature that it's showing in the house & the unit still won't shut off. I've replaced the thermostat & it still didn't help. I did accidently touch the two thermostat wires together & it shut off then.

I've got a two wire thermostat & I hooked the new one the same as the old one with the red going to one side of the RH/RC jumper & the white to the W. I've also hooked the thermostat up to the wires that run right off of the unit so it's not in the wires that travel through the wall. Like I posted, it seems that something in the unit went bad to create this problem & doesn't appear to be thermostat related. I did put in a new capacitor on the outside unit a few weeks before this happened.

Any help would be greatly appreciated, thanks.

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Robert
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Joined: Wed Feb 28, 2007 12:07 am
Location: Tennessee

On a 2 wire set up, t-stat closing turns a/c and blower off, so touching the two wires together created that and did shut it off.


That could mean a t-stat problem, however, if it still does it with new t-stat, may be something else IF new t-stat is correct.


Best way to know is trace test the circuit to locate where power is getting through where it shouldn't be.




Blower relay and t-stat reversing relay are top two suspects.


Find the two wires to outside condenser unit and see if you have 24vac across them with unit still running.


Also, test across 1 and 3 for 24vac at blower relay.




Thanks,
Robert
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Otis Campbell
Posts: 3
Joined: Fri Jul 31, 2009 4:28 pm

Thanks, I'll get my volt meter out & check them this week.
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Robert
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Joined: Wed Feb 28, 2007 12:07 am
Location: Tennessee

You're very welcome, happy to help.




Take care and best wishes,
Robert
Some people are Humbly Grateful, while some are Grumbly Hateful.................... Which one are you ?
Otis Campbell
Posts: 3
Joined: Fri Jul 31, 2009 4:28 pm

Update.. I checked wires & voltage today & the problem ended up being in the thermostat. I didn't try the old one again but the new one was wired right. When I was putting the two halves back together on the wall after checking the wires again it started working. One of the terminal connections between the two halves must not of been making good contact when I was snapping it together each time before.

Thanks again for taking the time to respond & help.
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Robert
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Joined: Wed Feb 28, 2007 12:07 am
Location: Tennessee

Great news, glad to hear it is working again. Glad I could help, you're very welcome.



Take care and best wishes,
Robert
Some people are Humbly Grateful, while some are Grumbly Hateful.................... Which one are you ?
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