A/C & Heat Pump Outside Compressor/Condenser Turns Off FAQs

Compressor/Condenser Shuts Off, won't keep running

A/C or Heat Pump Compressor/Condenser Won't Keep Running, Won't Turn Back On

Helpful Diagnostics:

• HVAC COMPRESSOR SHORT CYCLING ON & OFF - 5 most-common causes
• SHORT CYCLING AC COMPRESSOR - topic home - complete diagnostic procedure

A/C system starts then shuts off

My AC unit during the hot and humid months here in FL, will not run without some help from me. Lets say it is 80 degrees and you set the thermostat at 75, it will run until temp drops about 3 degrees, then shuts off.

You then need to shut the unit off via the thermostat, for approximately 20-30 mins turn it back on in order for the air to start blowing again. I tried changing out the thermostat but this has not helped. What could be the problem? - (June 8, 2012) Renee

Reply by (mod) -

Renee, often when shutting off the A/C returns the delivery of cool air we trace that problem to frost formation on the cooling coil.

Click on FROST BUILD-UP on AIR CONDITIONER COILS check for, diagnose, & repair that problem. But first, make sure that your air filter is not debris clogged.

Air Conditioner shuts down in very hot temperatures

A/C turns off during the hottest part of the day for two+ hours. On 2020-06-28 by Christine -

Reply by (mod) -

Christine

Some AC systems include safety controls that will shut the system off to prevent more-costly damage from, for example, overheated components or excessive refrigerant pressure.

So I suspect your system, when it's working hardest, has a component that's overheating or otherwise causing a condition that shuts the system down.

An experienced A/C service tech can track down the failing part.

Heat pump compressor turns off randomly

heat pump compressor turns off randomly but fan keeps running On 2020-05-22 by fred -

Reply by (mod) -

If not one of the causes above on this page, perhaps a bad relay, control, or even a loose or bad electrical connection.

Why does heat pump FAN turn on and off unexpectedly?

What will make your fan on a heat pump cut on and off On 2018-11-14 by Terry -

by (mod) - check the defrost cycle first

Possibly a problem with the defrost cycle.

Our new AC won't keep running - the compressor keeps turning off and on

My A/C compressor broke about two weeks ago, we got a new one but when the fan starts the compressor works for a while and then it shuts down, and its turning on and off and I dont know whats wrong - Help.

Reply:

Help: if your new A/C won't keep running after it has just been installed, surely you should call the installer and expect it to be repaired under warranty - it's just been two weeks.

Even if all of the new equipment is in good condition, an example of a problem that could occur during compressor replacement is that contamination, moisture, dirt in the refrigeration system (which is made worse if a compressor burns up) can interfere with proper system operation.

See our diagnostic procedure

at SHORT CYCLING AC COMPRESSOR

Compressor / Condenser Unit Won't Stop Running

Moved to COMPRESSOR / CONDENSER UNIT WON'T STOP RUNNING FAQs

HVAC Compressor/Condenser Fan Won't Start

Moved to COMPRESSOR / CONDENSER UNIT FAN WON'T START, WON'T RUN FAQs

A/C or Heat Pump Outdoor Compressor/Condenser Unit Won't Start / Won't Run FAQs

Moved to COMPRESSOR / CONDENSER UNIT WON'T START or WON'T RUN FAQs