Sunny days at the beach, cool tasty treats and dips in the pool are just a few ways to cool off in the summer, but the most satisfying way to cool off is to step out of the oppressive heat and into an air-conditioned home. However, it can be disappointing to find that the temperature inside isn't as cool as expected and worrisome that the solution could include an expensive repair bill. Before immediately calling a repair service, check to see if the apparent malfunction is something simple. If so, the problem can be easily and inexpensively determined and corrected by the homeowner.

First, make sure the thermostat is set at a desirable temperature. It may be that the interior temperature is already in the range of the thermostat's setting and the thermostat needs to be turned down a bit. If the thermostat is set to a cool setting but the temperature in the room is significantly warmer, see if the thermostat runs on a battery. Some thermostats require batteries while others run off the home's electrical system. If the battery dies in the thermostat the air conditioner will either cease to work or will work inefficiently. Replace the battery to find out if a dead battery is the cause of the air conditioner failure. Alexis Rohlin for homeguides.sfgate.com suggests, "Change your wall thermostat batteries once a year, or when the low battery indicator appears on the digital display."

Once the thermostat is determined to be in good working condition check to see if a vent is blocked. If there are weeks or months of the year when neither the heat nor the AC is in use the registers can inadvertently become blocked by furniture, large house plants, toys or other objects. Homeowners may sometimes even forget exactly where the registers are and, consequently, allow them to be blocked by dust and debris. The effects of these obstructions will eventually be realized when the temperature in the house fails to drop when the air conditioning is turned on. Elizabeth Flaherty writing for familyhandyman.com advises, "When HVAC troubleshooting, it is imperative to check vents, ducts, and grills for blockage as that can be the leading factor of irregular air flow." Also, check the outside unit to make sure the vents aren't blocked by large objects as well.

Another potential cause of a poorly performing air conditioning system is a dirty air filter. An air filter traps hair, dust and whatever airborne particles it comes into contact with as the unit draws in air to cool. If the filter isn't replaced in a timely manner, it will eventually get dirty enough to fail. A dirty or clogged filter also causes the air conditioner to work harder to pull air in. Therefore, more energy is being used and the unit's increased use of energy may be reflected in a higher electric bill. Another result of the unit's increased efforts is that it reduces the lifespan of the air conditioner. Emily Fazio writing for hgtv.com says, "The harder the system works, the faster it can be damaged or overheat." Replacing the air filter regularly will help keep the system running efficiently.

Central air conditioning is a welcome luxury during the heat of the summer. But when the house isn't as cool as it should be, a few minor homeowner maintenance repairs could possibly avoid a call to a repair service.