Could the thermostat be to blame?

Question

For the past several weeks, my heat pump has not been turning off when I run it. The furnace fan turns off when it is supposed to, but the outside unit keeps running. I have to turn it off at the circuit breaker. The outside unit works great. It just won't turn off. I turned on the A/C this evening, and it worked great. But the outside unit kept running after the furnace fan turned off. Could it be that the therostat just isn't turning it off, or is there something wrong with the unit itself?

If I turn on the heat, it puts out heat. If I turn on the A/C, it puts out cold.

Answer 1

there is two possible problems...One is the thermostat could be bad...the other is that the contactor or relay that turns the outside unit on is bad and has stuck in the closed position...this is easily checked ... first put thermostat in off position..every thing should go off ...if everything but outside unit goes off ...turn main power off on outside unit only...then remove cover where the controls are...trace thermostat wires and disconnect yellow wire from unit...turn power back on...if unit stays off thermostat is bad .... if unit comes on contactor is bad...this contactor costs about 20 bucks and is easily replaced ...if thermostat is bad depending on what brand unit you have and what thermostat it requires could cost anywhere between 70 to 150 dollars...heat pump thermostats are more expensive and heat pumps cannot use a standard thermostat

Answer 2

Your out side contacter is sticking prob. from some foreign substance most likely (bugs) ants are notorious for migrating in electrical circuits and getting fried in between the contacts.
Solution: Go and buy some contact cleaner or starter fluid.
Turn off the power and flip the breakers off to the units....
Find the panel on the out side unit where the wire are going into the unit.
remove them with a 1/4" nut driver or a 5/16 nut driver and locate what looks like a open end box its about 3" inches wide and about 3" tall it also has a bunch of wires coming out of it.
Spray off the part in the middle on the very top there are points that move up and down this is the part that is sticking.
Make sure that when your done the points that spring up and down are move easily they should be up always unless the unit is calling for ac.

Answer 3

I can't tell you for sure that the thermostat is the problem, but a new one only costs about $25 at Wal Mart. It's easy to install yourself. I just installed 2 of them today in my 2 units. Not all thermostats work for multistage heat pumps. Be sure to read the package before you purchase. By the way, I'm a 63 yr. old lady. I did it, so I know you can.

Answer 4

Most likely it is your t-stat. Once the 24 volts shuts off the contactor should break connection shutting of the 240 volts.
The following two sites will have some additional troubleshooting info for heat pumps if you want to read:

http://toad.net/~jsmeenen/wiring.html
http://www.longviewweb.com/visit.htm

Answer 5

The outside unit only has a fan, so if everything else works it's most likely a relay that operates that fan has stuck closed. It happens. If you can find that relay, the points are probably stuck (welded) together. Pull them apart and smooth carefully with a point file or fine sandpaper.

Answer 6

Sounds like your heat pump is OK. Could be the thermostat, yes. Basic ones aren't expensive, might be worth changing it to find out.

Answer 7

There is probably a switch that isn't shutting off the outside unit. Contact a repair man I doubt that problem is a very expensive fix.

Answer 8

I would agree it is a relay that is staying closed