You just turned on your central air conditioning for the first time this year and it doesn’t work. Or maybe it’s been running for a while and breaks down on a hot day. What next? Here are some common problems. See what you can fix yourself and when it’s time to call a professional.
Not cooling properly
All the things below can contribute to a hot house, but we’ll start with the basics. Check that the temperature on the thermostat isn’t set too high. Close windows and outside doors to keep the cool air from escaping. Clear any plants or debris that are blocking the condenser.
Condenser not running
The condenser is the metal box that sits outside, usually near the garage. Inside is a fan that transfers the heat in your home to the outside. If it stops working, there could be a power failure. Begin by flipping the circuit breaker (make sure the unit has cooled for at least five minutes first). Next, try resetting the high-pressure limit switch; the reset button is located in the compressor’s access panel.
If that doesn’t restore power then check for blown fuses. Dirty filters or coils can also cause a compressor to fail. If they look dirty then replace the filter or clean the coils. Still not working? It probably has wiring problems or a faulty thermostat. Call a professional.
Turns on and off frequently
For units that blow air, turn off, then quickly turn on again – something is wrong. It’s normal for the unit to shut off when it reaches the desired temperature, but too much is inefficient. It also wears out the compressor and fan. This can happen when the unit is too big for the size of the house, in which case you’ll just have to replace it. But more likely there’s a bad electrical connection. This is also a fire hazard and should be left to the professionals.
Refrigerant (commonly called Freon) is the chemical that cools the air. A system runs at its best when the refrigerant level matches the manufacturer’s specifications exactly, no more or less. If the refrigerant is low, then either the installation was done poorly or there’s a leak. Simply adding more liquid won’t fix the problem. You’ll want to call a trained technician. They’ll fix the leak, test it, and charge the unit with the correct amount of refrigerant.
Don’t wait until summer to test your central air conditioning unit. Turn it on during spring. That way you’ll have time to troubleshoot any problems before the weather heats up.