It's no fun when your AC stops cooling right in the middle of a heatwave. The good news is that in some cases the problem requires a simple fix — no tools required. Before calling in an HVAC contractor, check the following to see if one of these issues is at the root of your non-performing air conditioner.
1. Check the Filter
Some air conditioners go into an automatic shut down mode if the air filter is clogged or not seated in the housing properly. Even if the AC continues to run with a clogged filter, it may not put out sufficient cold air to actually cool your home. Simply changing the air filter will solve the problem. If it's badly clogged, you may need to use a stick duster or the hose attachment on your vacuum to get all the debris out of the housing.
2. Flip the Breaker
A blow circuit breaker will cause your AC to shut down completely. Breaker issues are more common during heat waves since there is a higher demand for power, which increases the chances of a power surge. Before calling in a professional, check the breaker box. Turn the breaker switch that controls your AC all the way off, then flip it back on. If the breaker was the problem, the issue should now be resolved.
3. Test the Thermostat
A problem with the thermostat is another common reason for AC failure. If you have a battery-operated thermostat, make sure the battery doesn't require replacement. Next, check that the AC is set to on and that the temperature is set lower than the current temperature in the home. If the AC still won't come on, try turning the thermostat down even lower. If the AC comes on at the lower setting, you may need a new thermostat to permanently fix the issue.
4. Look for a Freeze-Up
An AC can freeze up, particularly when it is working hard on an exceptionally hot day. Check the outside portion of the unit to see if there is ice forming on the coils. If there is, then turn off the AC until it can fall. ACs typically freeze up when they are low on refrigerant or if the temperature is set too low. You can use the AC again once it thaws, but it's a good idea to have it inspected as soon as possible.
Contact an HVAC contractor if you continue to have problems with your AC.