Michael Hartman, owner of Thomas E. Clark Plumbing, Heating and Air Conditioning in Silver Spring, Md., recommends keeping your air conditioning running while you’re at work. Turning it on and off puts a strain on your system. (iStockphoto)

The extreme temperatures that have been baking the Washington area these past few weeks are taking their toll not only on people but also on AC systems. Air conditioners are working overtime to keep our homes comfortable, and repair services are working overtime to keep them running.

“We are getting hundreds of calls in this heat wave, probably quadruple what we normally get. For my office staff, it’s like being on a hamster wheel,” said Michael Hartman, owner of Thomas E. Clark Plumbing, Heating and Air Conditioning (301-703-9079; thomaseclark.com) in Silver Spring, Md. “The main reason units are failing is due to lack of maintenance.”

Hartman said callers tend to sound more desperate during a heat wave than during a cold snap in the heating season. “In the winter, they say they’ll throw some extra blankets on for the night and we can come tomorrow,” he said. “But with no air conditioning, people are very, very desperate to get it fixed as soon as possible.”

There are many reasons your unit could stop working, including an electrical component failure or a refrigerant leak. Many problems can be dealt with on the first visit, he said.

We asked Hartman for ways consumers can help keep their systems running efficiently and head off breakdowns, and also for other ways to keep the house cool. Here’s his advice:

Get regular maintenance checks. You do maintenance on your car, so why not on your home? Regular service visits include cleaning your equipment, which helps it run more efficiently and can help decrease energy costs. Hartman suggests signing up for a yearly maintenance plan for cooling and heating checks.

Change filters frequently. Hartman changes his air filter once a month. He uses a midrange filter rated MERV 8. A clogged filter can cause a unit to work harder, which can lead to a system breakdown.

Run your fan 24/7. Running the fan on your unit all the time cleans the air and keeps it moving throughout the house. This can also keep rooms on all floors at a more even temperature. Hartman said that the very small amount of energy it uses is well worth it, in terms of comfort and efficiency.

Don’t turn the AC off when you go to work. If you turn it off in the morning and then turn it on when you get back in the evening, the system will be working extra hard to cool the house, and that puts a tremendous strain on it. Instead, turn your thermostat up three or four degrees when you leave and turn it back down when you return. Or, better yet, get a programmable thermostat and figure out how to use it.

Keep blinds and curtains closed during the day. Do all you can to keep the heat out of your house so you don’t have to cool it as much.