Here's how to keep the house cool inside as the outside temperatures go up this summer, if you have an air conditioning system in your home.

Get your system checked out

Last year you thought, “We’ll worry about it next summer.” Well, that time is now. You don’t want to be without air conditioning on a particularly warm weekend.

Even if you have a well-running unit that is relatively new, you want to do the yearly maintenance on it.

“They are just like our cars,” says Shannon O’Roark, a sales representative with Air Conditioning Specialists. “Preventative maintenance keeps them running right.”

But unlike our cars, air conditioners actually start and stop more, says Joe Strazza, president of Precision Heat and Air.

A technician will first turn down the thermostat to make the unit run and then check the temperature coming out of the unit. It should be about 20 degrees cooler than the thermostat reads. He’ll check the blower speed and the blower amps, as well as the static in the unit. He’ll also check the drainline and the filter.

Outside, he’ll check the amp draw that is coming out of the outdoor unit. Each system has a maximum amp draw, and it should be well below that. He’ll also inspect the outdoor unit including the condenser, the compressor and the capacitor and clean it out to make sure the coils can breathe properly. He also should spray ant repellent around the contactor.

A good checkup should do more than just look at the unit, says Chris Strand, owner of Stan’s Heating and Air Conditioning. They should be cleaning it and tuning it up.

While this checkup doesn’t guarantee that nothing will go wrong, it can indicate potential problems for the summer.

“If I could predict and tell you this is the day that your system is going to fail, then I would be a person in high demand,” O’Roark says. And even if you do regular maintenance, other things can happen, including a power surge or a lightning strike, that can take out a system.

Not built to last

In some hotter regions, air conditioners can only last about eight to 12 years. In fact, the outside units are meant to work well at up to 96 degrees. With each additional degree, it adds a tremendous amount of strain, Strazza says.

Some units might last longer, but they become inefficient.

And don’t be surprised when you need to replace the air conditioner that you probably will have to replace the furnace or the heat pump. The systems need to match. When you do replace, it’s a great time to do an energy audit and make improvements such as weather stripping, improving duct work and adding insulation. Austin Energy offers rebates that make it affordable to do the audit and improvements at the same time you add new units.

Change the filter

There are several things you can do to make your air conditioner keep on cooling. First, change the filter regularly. If you have a 1-inch filter, it’s every month. A 2-inch filter is made to last three months and a 4-inch is made to last six months. Make sure you know how thick the filter needs to be for your system.

For 1-inch filters, you want one with a MERV rating of 7 or less. The higher the rating, the less air can get through; too high a rating doesn’t let enough air get through and just clogs the system.

Sometimes you need to change the filter more than the prescribed times. If you have hardwood floors, tile or vinyl, you don’t have carpet to trap the dust. Also, if you have pets, you’re adding dander and hair to the system. Especially in summer, check the filter every month, even if you have a three-month or six-month filter.

Flush the drain line

Air conditioners are removing up to 10 gallons of water a day as they remove humidity in the air. If that water has no place to go, it can back up in the inside unit and flood your house. About four times a year, you should flush the drain line. That’s the 3/4-inch PVC pipe sticking out in the indoor unit. Technicians used to recommend a bleach solution, but that actually can do more harm than good. Now, white vinegar or a vinegar-water solution is recommended, though everyone has a different combination, from a 1/4 of a cup to a cup either combined with water or poured in first and then flushed with a gallon of water immediately afterward. Either way, it will remove calcium deposits and prevent gunk from growing in the line.

Wash the outdoor unit

Just like changing the filter, you have to let the coils that are found on the sides of the outdoor unit breath. Turn off the breaker or pull the disconnector first. Then use a hose without a nozzle on the sides of the unit. You are washing the hail guard, also called the fins. It will look like vent slats or bars on the outside. Run the water from the top of the hail guard to the bottom. You’ll want to do this about four times a year, more in the summer and more if your unit sits near your dryer vent or you have a lot of bushes or trees, especially cottonwoods, nearby.

Keeping the condenser coils clean helps prevent the capacitor from exceeding its limit, getting too hot and swelling up like a balloon, Strazza says. You’ll stop getting cool air then. The capacitor is the most common repair he does and is usually a $100-$300 repair.

Keep the outdoor unit nature-free

You want to keep the shrubs and grass away from the unit as well as sprinkle or spray ant repellent around it.

It’s hot in here, right?

When it doesn’t feel like your system is working right — it’s running all the time and not cooling, it never reaches the desired temperature, you’re hearing a weird noise or it’s not running at all — it’s time to call a professional. First, do some investigating. There are two pipes that run from the house to the outdoor unit. The insulated one should be cool. The non-insulated one should be hot.

Also check the batteries in the thermostat and check that the breaker hasn’t been tripped. The batteries in the thermostat you can fix yourself. Don’t flip the breaker back on because you could do more harm than good. Call a professional.