Understanding and Maintaining Your Central Air Conditioner

by Dave Donovan

Most people cannot live without their central air conditioners. It's what they look forward to most when they head home after a long, hot day of work in the middle of August. For the most part, central air conditioning systems are trouble free and require only a minimal amount of routine maintenance.

We have the luxury in this modern age of being able to control exactly when, and for how long, our A/C will run with the use of programmable thermostats. They allow our system to be as efficient as possible because they can turn the system off in the middle of the day when no one's home and then turn it on right before you do return home. Not only is it convenient but it saves on the electric bill as well.

Central air conditioners can seem complex to many people, but they work in a similar way as does the refrigerator in your kitchen. Some of the main components of a central air conditioning system include:

Outside components:

Electrical disconnect switch
Condenser coil
Fan and motor
Compressor

Inside components:

Furnace with blower
Condensate drain and pump
Condensate tray
Evaporator coil
Plenum and ductwork

Here's how your modern central air conditioner works.

Refrigerant circulates between the outside condenser coils and the inside evaporator coils. While the refrigerant is inside, it absorbs heat from the room, then travels to the compressor. The refrigerant is compressed by way of heat. The heated refrigerant leaves the compressor and enters the condenser where the refrigerant gets condensed as the heat is removed from it. Then the cold refrigerant gets sent back to the evaporator coils.

While this is happening, the blower forces air through the cooled coils into the rest of the house by way of the ductwork. As the heat leaves the air, it's forced to give up its moisture. The moisture is called condensate. The condensate gathers in a pan and is eventually removed by the pump, which sends it to a drain in your home.

Most central air conditioning systems share the same ductwork and blower as the furnace in your home. That means that they also share the same filter. You should check your filter at least three times a year because they can build up a lot of dirt in a quick amount of time. A clogged filter can cause your system to run poorly and increase your utility bills. Families with pets should change their filters even more often.

Here's a list of some other central air conditioner problems and their remedies:

Problem: The central air conditioning doesn't turn on.
Solutions: The central air should be on a dedicated circuit. Check the electrical panel to make sure the breaker didn't trip. If that isn't the problem:

Check the disconnect box near the compressor to see if it was turned off.
Check the furnace power switch.
Check the access panel near the compressor. On hot days the compressor may shut down, requiring you to press the reset button.

Problem: The central air runs but doesn't cool.
Solutions: Check the filter. It may be clogged and restricting air flow. Some other things to check include:

Check the condenser cover outside and clean up any debris on or around it.
Make sure the thermostat is set to cool and not heat.

Problem: The central air looks like it's leaking.
Solutions: Check your condensate pump and make sure there are no leaks in the drain hose. Some other things to check include:

Check the outlet that the condensate pump is plugged into for power.
Check your filter. Clogged filters can cause the formation of ice in the tube.

These are just a few of the potential problems you may experience at any time with your central air conditioner. Most importantly, always remember to check the filter on a routine basis. It can save you a lot of trouble down the road.