Outside unit running, but thermostat is off

by Suna
(Freehold)

We noticed that our outside ac unit runs (the fan) even though the thermostat control is set to "off" inside the house. Is this a problem with the unit, or the thermostat inside the house?

We currently have the system shut off at the breaker to prevent it from running. Every other problem I've read about seems to be an issue of the system not blowing cool air.

We just don't want the system to run at all as there is no need with the cooler weather.

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In addition to the fan running....
by: TN-Goose

I should also mention that the fan will run at full speed when the indoor thermostat is switched ON, but a split second later, the breaker trips and the A/C unit stops completely. Could this be a "frozen" compressor issue? I have a Rheem Classic unit about 7 yrs old.

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Fan keeps running at mid-speed
by: TN-Goose

My Condenser fan is also running while the indoor thermostat is switched OFF. Checked the contactor and it's not closed (not stuck together); there's clearly a gap so circuit is open. Don't see any bad wiring connection. No insects or debris in contactor. Howvever, replaced the run capacitor (dual 50/3 MFD) after check results showed 44.5MFD/3.08MFD. Still, it did not resolve the baffling condition of the fan rotating at half-speed. Any idea why?

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How much would it cost?
by: Chester

If this is the problem I know how much it would cost here, but I can't quote prices or labor rates in your area. Call a local heating and air contractor to get an estimate.

You will be charged for a service call and the price of any parts.

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how costly is this?
by: ccpiek3

NAny idea how much this cost?



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Outside unit runs all time
by: Chester

Sounds to me that the contactor for the compressor and outdoor fan motor is stuck closed. This is a frequent problem caused by the points arcing on start and stop, they sometimes get welded closed.
The fix is to replace the contactor. This should be done by a qualified HVAC technician.

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