Compressor/Condenser Unit Fan Won't Stop FAQs

A/C & Heat Pump Outside Condenser fan won't stop running

Condenser Fan Won't Stop FAQs

Helpful diagnostic

• CONDENSER FAN WON'T STOP

Condenser Unit Fan Never Stops

Why does my condenser fan run constantly? On 2021-06-13 by Kevin

Reply:

@Kevin,
Depending on:

- the cooling capacity of your system

- the air leakiness of the building

- the building's insulation system

- the building's heat gain through windows, sun exposure etc.,

- the thermostat settings

- system maintenance condition (such as a dirty air filter or dirty blower fan that reduce A/C output)

- probably some other factors

an air conditioner or heat pump in cooling mode may run continuously in very hot weather without that meaning that the system needs repair.

After that, in the above FAQs, please note the following response:

"On some compressor / condenser units the fan may run before or after the compressor motor has shut off, but it should eventually stop. If it doesn't, there is a control or wiring problem to be found and repaired.

In that case, I suspect a wiring short or a control board or relay failure at the compressor/condenser. I'd shut off the system and ask for service."

The below article will also give you more information on HVAC diagnosis (this is the home page to the page on which you posted your question).

OUTDOOR COMPRESSOR CONDENSER UNIT PROBLEM DIAGNOSIS

inspectapedia.com/aircond/HVAC_Condenser_Unit_Diagnosis.php

 

Question: outside compressor / condenser fan won't stop running

(Mar 5, 2015) Tak said:
Outdoor fan keep running even if we have the system turn off by the thermostat

(Mar 7, 2015) Susan said:
I turned my heater off and kept hearing it running. It's a heat pump and everything was frosted over. I just pulled the outside ac breaker out. What could be the problem

(Sept 14, 2015) Brent said:
My unit is cooling fine but the compressor and outdoor fan does not shut off even when I turn the thermostat to off.

Reply:

Tak

On some compressor / condenser units the fan may run before or after the compressor motor has shut off, but it should eventually stop. If it doesn't there is a control or wiring problem to be found and repaired.

In that case I suspect a wiring short or a control board or relay failiure at the compressor/condenser. I'd shut off the system and ask for service.

Brent, a search of the InspectApedia website for "COMPRESSOR WON'T STOP RUNNING" finds

COMPRESSOR / CONDENSER DIAGNOSTICS

that includes a section titled

Step 5: THE COMPRESSOR/CONDENSER RUNS TOO LONG or NEVER SHUTS OFF

Reader question: What happens if condenser fan stop running

What would happen if one of my condenser fan's stop running? 2018-02-17 by Will

Mod reply:

The condenser unit cannot function and should shut down on over pressure or temperature.

Reader question: Compressor contacts disengage and fan still runs

Compressor contacts disengage and fan still runs, disconnected thermostat and still runs, wont shut off unless pull disconnect. 2017-07-09 by Ron

Mod reply:

Ron

Which fan - outside compressor/condenser?
Anyway, look for

- shorted thermostat wires - disconnect them at the blower or compressor unit end

- a bad fan relay

Reader question: Carrier Ac keeps running, shutting off, restarting

I have a new carrier 2 1/2 ton 83,000 but heat pump. When the ac is running and it reaches the temp on the thermostat, the cooling shuts off, then immediately restarts and runs for a few minutes, then stops again. What causes this? 2017-07-04 by Lynn

Mod reply:

Good question. I'm not sure of the cause but suspect

A bad thermostat

Loose or corroded wires or connection

A bad a.c. control or relay