Things to Try if Your Air Conditioner Outdoor Unit Will Not Shut Off

San Rafael

(415) 942-6565

Santa Rosa

(707) 452-3464

The outdoor unit or condenser unit of an AC is one of its most important parts. Its job is to remove the heat absorbed from the air inside the home by the indoor unit. Without the outdoor unit, the heat absorbed by the indoor unit would have nowhere to go.

The outdoor unit consists of three parts: the compressor, condenser coils, fan, and refrigerant lines.

The compressor is the heart of an AC. It moves the refrigerant between the evaporator and condenser coils. As the refrigerant flows through condenser coils, a fan blows air over them to cool them off. Refrigerant lines connect the indoor and outdoor units to cycle refrigerant.

Sometimes, an AC outdoor unit won’t shut off. The problem can affect your AC’s efficiency. If you ignore the issue, not only will your energy bill shoot up, your AC could break down.

If the problem occurs and you do not shut off your AC, the indoor unit may freeze. However, if you continue to run your AC, the ice may continue to build up to the condenser unit.

Here are some common causes of the problem.

Stuck Compressor Contactor

This is one of the most common reasons why condenser units won’t shut off. The contacts of a contractor can become pitted over time and wear down. In many cases, the contacts stick together or weld shut in a closed position, preventing the outdoor unit from shutting off.

If this is the problem, have your HVAC contractor replace the contractor. However, before you reach out to a pro for help, check the contractor to see if it is just stuck but not damaged.

To unstick a stuck contractor, tap on it. Using a small wire brush, clean the contactor. This is a temporary solution, and you will have to replace the contractor ultimately.

The average cost of replacing a contractor is $180. How much you will pay to replace your contractor will depend on a number of factors such as the cost of the part, and the time of day (expect to pay more if you hire a technician for replacing the contractor after hours).

A good rule of thumb is to replace the contractor every two to three years. Because contractors are made from copper, it is a poor conductor than many other costlier metals such as silver.

If you want to avoid the hassle of changing your contractor at regular intervals, use a commercial-grade contractor. Though you will pay more upfront, chances are you won’t have to change your contractor again.

Bad Thermostat 

A bad thermostat may send a signal to the outdoor unit even when it is not supposed to. If you are not sure that your thermostat is the culprit, carefully unplug the yellow wire (connected to the cooling system) from the Y terminal. Does your unit shut off? Your thermostat is defective. Talk to an HVAC technician about your options.

Damaged Thermostat Wiring 

Your thermostat cable can get damaged due to many reasons. It can get damaged by a weed eater or weed whacker, or mice may have chewed the cable, or maybe you put a nail through the wall that punctured the wires.

If the wiring is too old, the protective insulation around it might have deteriorated, exposing the copper wires. Exposed wires then touch and maintain a constant electricity supply to the compressor contractor keeping the outdoor unit running.

To check the indoor wiring, take off the thermostat cover and remove the screws holding it to the wall. Next, check the conduit housing the wiring and inspect any bare wires for damage.

This is an electrical problem and is best left to an expert. After the technician arrives, the first thing they will do is determine if the damaged wiring or thermostat itself is causing the problem.

If damaged wiring prevents your outdoor unit from shutting off, the technician will replace the wiring connecting the thermostat to the condenser.

If you suspect that rodents or a weed-whacker damaged the wiring or that you or someone else accidentally damaged the wire while hammering a nail through the wall, build a fence around the external unit to prevent the problem from recurring.

Maintain Your Outdoor Unit 

Your outdoor unit is exposed to the elements and may need more frequent maintenance than the indoor unit. To prevent problems:

  • Maintain your outdoor unit regularly
  • Keep the area around it clean
  • Trim vegetation back around your condenser unit

Clean the outside unit with a commercial cleaner. Using a soft brush, remove the dirt accumulated on the fins. Straighten bent fins. Check the concrete pad on which your unit rests. If the soil under it has settled, causing your unit to lean or tilt on one side, lift the pad with a pry bar and place gravel or rocks under concrete to level your unit.

To protect your condenser against the elements, cover it with a commercial condenser cover.

Need air conditioning repair services near you in Rohnert Park? Look no further than John Owens Services. Whether your condenser unit is acting up or your internal unit is not working the way it is supposed to, we will have a solution. To schedule an inspection, call 707-452-3464.

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San Rafael
(415) 942-6565
Santa Rosa
(707) 452-3464



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San Rafael
(415) 942-6565
Santa Rosa
(707) 452-3464