Window AC Compressor Keeps Running When Power Is Shut Off

man working on window air conditioner

Window air conditioners are a good simple solution for most homeowners who do not have a budget for a central AC. Although they cost just a fraction of what central ACs do, they can serve a moderately sized home quite well. In most cases, a good window AC could serve you for as long as 15 or even 20 years. However, there are issues that are likely to pop up during your AC usage.

The one problem that most AC users have reported is that the compressor continues running even when the power is turned off. This is a serious problem that can lead to power wastage. Most users of modern window ACs have gone through this problem.

In this post, we will be looking at a scenario where the compressor keeps running after the power goes off and see the solution. As a DIYer, you want to find a durable solution to this problem that will guarantee using your AC for a long time.

When the AC malfunctions such that the compressor continues running when the power is off, there are a few potential issues. These issues may include frozen evaporator coils, clogged air filters, the electrical relay switch, or the fan. These components may malfunction and cause the AC to malfunction entirely.

These are the components you need to check when the compressor malfunctions:

Electronic Control Board (PCB Assembly)

The first component you want to look at is the electronic control board. The PCB is the central control unit of the AC. It sends out signals to determine when the compressor should run and when it should stop. If the PCB is damaged, there will be a malfunction that will affect the operations of the compressor.

The good news is that you can replace the PCB. To replace the PCB board, visit an electronic supplier and find a board that matches the one in your AC. You may also want to contact the manufacturer for a functional one. However, before you even think about replacing a PCB, make sure you check for other potential issues.

Temperature Controls

The first aspect of the AC that you should look at even before you consider PCB replacement is temperature control. Some ACs have manual temperature controls, while others are automatic. Whichever you have, make sure the temperature control works well. Check the settings to confirm that the temperature recorded is correct.

The thermostat, which takes care of temperature controls, is the sensor that takes note of room temperatures. It then passes the information to the PCB, which in turn initiates the actions of the compressor. The temperature control helps with the automation of room temperature to ensure that the house is regulated.

Thermistor (Temperature Sensor)

The temperature sensor is very key in controlling the operations of the AC. It determines when the compressor should be running and when it should not. If the sensor is damaged, the compressor will continue running throughout the power.

The good news is that the thermistor can easily be replaced, and the system will keep on running well.

Stuck Dials (Relay Switch)

The other common problem that causes the compressor to misfunction is stuck dials. This is when air conditioners with rotary dials are used. The dials are supposed to complete the circuit and turn on the compressor when the room temperature is high.

If the dials are stuck, the compressor will keep on running even after the ideal temperature is required.

Inefficient (Undersized) Air Conditioner

If all the above situations are not the problem, chances are that your AC is undersized. Make sure you have the right size of AC that will provide sufficient control for your room size.

Bottom Line

If the compressor is not running well or if it keeps running even when the power is off, check the above issues. You may be required to spend some money to replace key parts such as the PCB and others.