Going without air conditioning through the hottest summer months is never an enjoyable experience. On the other hand, nobody wants to make a potentially expensive air conditioning service call if there's nothing wrong. Soaring temperatures can stress many air conditioning systems, so a slightly warmer home than you'd like doesn't always mean that your AC is on its last legs.
If you think you might have a problem, but you want to be sure before calling in a technician for repair, these three simple steps will help you determine if your system is misbehaving.
Listen for the Compressor
Most modern residential homes use split-system central air conditioners. These systems consist of an indoor air-handling and evaporator unit and an outdoor condenser unit. The condenser unit contains your compressor, and it's hard to miss, even if you don't know anything about HVAC equipment. If you can find the big gray box outside your house with a large fan on top, you've found your condenser unit.
Your thermostat should call for cooling when it reads a temperature higher than your current set point. Stand outside near your condenser unit and have a helper turn your thermostat several degrees lower than the interior temperature. You should see the fan start turning and hear the compressor turn on. If you can't hear the compressor, that's a good warning sign that you've got a problem.
Check for Power
Before condemning your AC system, it's always good to confirm that it has power. Central air conditioning systems require a separate circuit, so there should be a breaker that controls your air conditioner. If the breaker is off, flip it back on and see if that solves your problem. You should also check the quick disconnect near the condenser to confirm that it's plugged in and turned on.
Note that an air conditioner that routinely trips its breaker is having a problem, and you should avoid using the system under these conditions. If the breaker keeps tripping, leave it off and call in a professional for help.
Measure Your Air Temperature
If you want to be sure that there's a problem, you can use a small thermometer to measure the temperature at your return and supply vents. The temperature difference will vary between models but will usually be around 20 degrees or less. A very low difference, such as a few degrees or less, can indicate a maintenance issue or another repair problem.
However, it's important to remember that the difference in the temperature you measure won't be perfect, and there's no exact amount that you should expect. When in doubt, don't be afraid to call up a local HVAC technician and ask if the amount you measured is within an acceptable range for your air conditioner. If not, a repair may be in your future.
Reach out to an HVAC contractor near you to learn more.