My central air has been working just fine through the summer. Today it stopped working. Is this a common problem that is easy to fix?
Yes, quite common. Your HVAC system is a machine that has moving parts and electrical circuits that are bound to fail at one point or another. In addition to the mechanical side of your system there is the refrigeration circuit as well. 80% of the time a unit stops working as it should is caused by an electrical or mechanical problem. And only 20% of the time will it have anything to do with your refrigeration circuit. The top 3 reasons an a/c unit stops cooling are:
1) Capacitors – when a capacitor fails either the compressor or fan motor won’t get enough starting torque to get it turning. A simple replacement will get your system up and running again.
2) A break in the control circuit – many different reasons on how or why this could happen. A blown fuse, a faulty thermostat, worn out contactor or even something chewing through some wiring. A skilled HVAC technician will be able to locate the issue and not only fix it but also fix the issue that caused it.
3) Refrigerant charge – although the least likely reason, it still happens. Only reason a system would have a charge problem would be due to leaks or improper servicing. A leak test, with proper equipment, can pin point the leak source and save you from having to keep calling someone out to “charge” your system.