If your heating system fails on a cold winter day, you can put on more clothes. But if your air conditioning quits on a 100-degree day in August, you’ll probably have to suffer. Repair crews tend to be really busy during heat waves and may not get to you for days.

How much smarter it would be to head off potential problems before the really hot weather arrives.

Many Rogue Valley homes are cooled by air circulating systems like electric heat pumps and gas-powered air conditioners. But quite a few older, smaller homes still rely on the air conditioners you mount in a wall or window. So, planning for summer will vary depending on your equipment.

While it’s always a good idea to have your system checked by a professional at least once a year, here are some steps you can take on your own.

Make sure you are changing your furnace filter on a regular basis. “That is the single most important thing,” says Jeff Cool, an appropriately named service technician with National Heating and Air Conditioning of Talent.

How often should you replace filters? Usually once every month or two. “This will depend on the house and your lifestyle,” says Greg Hafner, president of Aire Serv Heating & Air Conditioning of Medford, since dust and cigarette smoke can be factors. “You’ll soon get a sense for how long a filter will last.”

Heat pumps and similar systems have an outside unit that pulls air in and out. Unfortunately, they can also pull in weeds and leaves, says Cool. You can alleviate that problem by hosing off the unit. First, cut off the power. Then shoot water directly into it, not at an angle. Explains Hafner, “If you shoot water at an angle, you run the risk of bending the metal grating on top of the unit.”

If you have an attic unit, make sure the pan is clean and that no debris is blocking the drains, Hafner adds. And check your thermostat to be sure it is level. If it isn’t, that can cause you to use more energy.

Are there ways to tell that something may be wrong with your system?

If you have a heat pump, keep a close eye on your electric bill, suggests Matt Varnum, an estimator with National Heating and Air Conditioning. If it’s suddenly higher than normal, there could be a malfunction.

What about the ducts? Should you get them cleaned out every few years? If you have good filters and change them regularly, you may not need duct cleaning, says Hafner. But if you notice a lot of dust or an odor, have them checked.

If your duct work is under the house, keep an eye out for possible damage from animals or water. As Varnum mentions, “Cats love under-floor ductwork if they can get to it.”

Is your system powered by gas and been in use for years? Get a carbon monoxide detector, just to be safe, Cool suggests.

If you simply have an air conditioning unit mounted in a wall or window, there are still things you can do to get ready for summer. “These units have filters behind the plastic grill that should be cleaned out periodically,” says Hafner. “If the exterior of the unit is dirty, you can hose it off — carefully.”

There are steps you can take yourself, although for peace of mind you may want to have a professional examine your system once in a while.

“If a unit is serviced regularly, it will run more efficiently and at less cost,” says Hafner. “Also, the technician can check to see if there are parts that are wearing out.”