Are you tired of your house never feeling cool enough? We understand! That’s why we’ve compiled a list of common air conditioner problems and solutions to fix them. But don’t worry...if it turns out there’s an air conditioner problem you can’t resolve on your own, you can always count on the HVAC experts at Crystal to help!
Common Air Conditioner Problems
Here are some of the issues we hear most frequently from our customers.

The Air Conditioner Stopped Working
When you don’t hear the AC running at all, you can try a couple of things.
- Thermostat batteries. If it’s been several years since you changed the batteries in the thermostat, try replacing them. Then make sure the thermostat switch is set to “cooling” mode and designate your desired temperature to see if the AC kicks back on.
- A tripped breaker. Locate your breaker box and see if the AC breaker has tripped, or turned to the neutral position. If it is, flip it to “on” and see if you hear the AC turn on. If it doesn’t, call us.
Room Temperature Air is Blowing Out of Vents
One of the most common AC issues we hear is that the air conditioner is on but it’s not blowing cold air. Possible causes for this could be:
- A dirty air filter. A clogged filter doesn’t allow your AC to work efficiently, so try swapping it out for a clean one.
- A broken or outdated thermostat. Thermostats are only made to last so long, so if yours is old, replace it.
- Leaking refrigerant. Your AC has to have the right amount of refrigerant to cool the air. When there is enough, the refrigerant line will sweat and feel cold to the touch. If there’s a leak, the coolant in the larger of two copper refrigerant lines will be low.
- Leaks in ductwork. Cool air may not be getting through because it’s escaping through gaps and cracks in your ducts before it reaches its destination. Having your ductwork checked is never a bad decision.

Some Rooms are Hotter Than Others
When your home’s temperature fluctuates from room to room, it’s not always due to air conditioner problems. It could be because of:
- Leaks in ductwork leading to certain rooms.
- Blocked vents. Make sure there’s no furniture or rugs covering the air vents.
- Poor insulation. It’s common for upstairs bedrooms, especially those above the garage, to be hot if there isn’t enough insulation in the attic or garage. You may want to speak to an insulation company about how to keep hot air from creeping in and cool air from leaking out.
- South-facing windows that absorb sunshine. Sunshine will always heat up a room, so try using blackout curtains or keeping blinds closed during the warmest hours.
Strange Noises Are Coming from the Air Conditioner
Odd sounds are never good when it comes to your AC. If you hear any of these, call Crystal right away.
- Screeching or squealing. This can happen when there’s a motor bearing problem or a faulty belt. It may just require lubricant but it could also mean a belt is about to break.
- Rattling or banging. This indicates an issue with the motor or blower assembly, both of which can cause your air conditioner to quit completely.
- Smacking, as if playing cards are hitting a bicycle spoke. This could mean something is caught in the blower blades. Turn off the system and check for debris.
- Clicking when the system turns on and off. This could mean there’s a relay problem that needs to be addressed.
Even Common AC Problems Should be Addressed by Professionals
If you notice that your air conditioner is acting funny, it’s best to address the issue before it becomes a bigger problem. Besides causing an uncomfortably warm home, a neglected air conditioner can lead to a breakdown of your entire HVAC system.
Crystal Heating and Cooling has been fixing air conditioner problems for St. Louis residents since 1965, and we always make our customers’ comfort our priority. Make an appointment with the most trusted heating and cooling company today so you can enjoy a cooler tomorrow!
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