When your air conditioner continuously shuts off before it has cooled your house to your set temperature, it's usually because one of its components is starting to fail but hasn't stopped working completely. Failing parts can disrupt power, freeze up your evaporator coils, or even cause moisture to back up into your air conditioner and trigger its safety mechanisms.
Electrical Component Issue
Problems with various electrical components of your air conditioner can cause it to run intermittently when they begin to fail. One possibility is problematic fuses, which act as a safety mechanism. When they fail, your air conditioner will no longer receive enough power to run. Another possibility is the capacitors, which provide power to jump-start the fan motor and keep it running.
While rarer, it's also possible that there could be an issue with the circuit your air conditioner is installed on. This can sometimes cause the breaker to trip, but even if it doesn't, it's still worth having a professional inspect your circuit and parts to make repairs and replacements if necessary.
Filter or Coils Are Dirty or Freezing
If your air filter is very dirty, it can restrict airflow to your air conditioner, which, in turn, can make it overheat and shut down early to prevent damage. It can also cause your evaporator coils to freeze up, which will make them stop working until the ice has melted. Similarly, if the coils are dirty, this can have the same effect. Frost builds up more easily on dirt and debris stuck to the coils.
In these instances, making sure your filter and coils are clean will often fix these issues. If this has been happening for a long time, the coils themselves could be damaged and may need to be replaced as a result.
Condensate Drain Clogged
Part of the air cooling process involves pulling moisture out of the air, and that moisture needs to go somewhere. When everything is working properly, this moisture will be directed harmlessly away from your home via the condensate drain. If this drain is clogged or damaged, however, this moisture may back up into your air conditioner itself, which will often shut off automatically as a method of protecting itself and your home from water damage.
Many condensate drains also have a backup drain, but if the clog is near enough to the drain pan in your air conditioner, or if the backup is also clogged, the moisture will have nowhere to go, and your air conditioner will continue to shut off until the drains have been cleared. A professional can inspect, clean, and repair your drain and drain pipes as necessary.
Contact an AC repair service near you to learn more.