Last summer, Maureen Mueller faced a classic Memorial Day hot spell, so she kicked on her air conditioner. It blew warm air. Welcome, summer!

After one of the harshest Chicago winters in recent years, prepare for a different degree: temperatures in the 90s and humidity levels to match. A reliable air-conditioning system makes your home an oasis of relief, and a broken one means misery—or, in extreme cases, death. (The Chicago heat wave of 1995 killed more than 700 people.)

Mueller, a Skokie resident, called several local companies. You want us to come out on a Saturday? A holiday weekend? Ha! But then she reached E. F. Bassing, a family-owned business that also specializes in heating, roofing, and sheet metal. Not a problem, they said. The owner came out himself. The repair estimate was more than what Mueller wanted to put into an aging unit, so she opted for a new one. Basser installed the equipment the following Tuesday, leaving Mueller cool and happy. “They got me going again and really seemed to care,” Mueller says. And her system? It’s been running fine ever since.

Fortunately, there are plenty of air-conditioning and heating service companies across the area that earn similar praise from their customers, according to an evaluation of 307 businesses by Chicago Consumers’ Checkbook. The nonprofit magazine (checkbook.org) collected more than 13,000 ratings of companies by surveying more than 100,000 Checkbook and Consumer Reports subscribers, checked on complaints on file with the Better Business Bureau and the Office of the Illinois Attorney General, and compared each company’s prices for a sample of specific repair and installation jobs. In all, 119 businesses received Checkbook’s top rating for quality. But here’s the better news: Turns out 28 of those companies also offered the lowest prices. Those businesses are listed on the chart on the next page.

To compare prices, researchers—without revealing their affiliation with Checkbook—provided specifications for routine jobs and found big differences. Prices to install a popular programmable thermostat, for example, ranged from $150 to $400, with an average cost of $263.

The chart also shows how prices at these 28 companies compare with the average prices for all the 307 evaluated. For example, at Comfort Care in Batavia, you could expect to pay $81 for jobs that on average cost $100 elsewhere.

For repair jobs, call and describe the symptoms. A company should be able to tell you over the phone what’s likely to be wrong and give you a price, assuming a correct diagnosis. If you can’t get a preliminary diagnosis and estimate over the phone, you’ll have to schedule a service call. If the first company that comes to your home gives you an estimate that is a few hundred dollars or less, it usually makes sense to have them go ahead with the work—it saves the time of having others come to your home, as well as paying the minimum service charge for the visits. But before paying, get a detailed invoice, including a description of the symptoms before the repair, a list of all labor charges and parts replaced, and a written warranty.

If the repair estimate is more than $500, shop around. Get several businesses to give you written proposals. You might save hundreds on a repair job, or even thousands on the installation of new equipment. If you need a new system, compare their proposed designs and the reasoning behind them. How well your system is designed affects comfort, noise, and vibration levels, as well as future maintenance, so ask for a performance guarantee: Get places to promise a certain standard, such as maintaining an inside temperature of 78 degrees or cooler if it’s 85 degrees outside. Then negotiate for at least a year’s warranty against defects in installer’s equipment or workmanship. Finally, ask if you can hold off on making the full payment until the job is finished or, better yet, after you’ve run the system for a while.

Of course, prevention is one of the easiest ways to avoid major catastrophes. Change your air filter. Dirty filters tax the system, and extremely filthy ones can cause air-conditioning condensing coils to fail. Check your filter each month. If you can’t easily see through it while holding it up to a light, replace it. You’ll probably need to replace the filter two or three times for each cooling season and heating season. Clear debris away from the outdoor unit. Keep the grilles of the unit free of grass clippings, leaves, and other debris, which can inhibit airflow.

Got a heavily used or old system? In those cases, scheduling an annual maintenance visit before temperatures rise can be a good idea, but beware of maintenance contracts for newly installed systems. There is little hard data that supports the value of annual visits. Some systems run fine for years without professional care. If you do decide you want a contract to cover unforeseen repairs, be sure to check what exactly is covered, and be careful not to pay more for the contract service than you would ordering repairs individually at regular labor rates. Checkbook found prices for one contract with the same coverage ranged from $100 to $175.

Remember that equipment typically breaks down during heat waves. Even if you have a maintenance contract, the company may not be able to keep pace during these peaks. And keep in mind that some very costly repair jobs—like replacing an air-conditioning compressor—are usually not covered by maintenance contracts. Should you start to melt while waiting for service repairs, drink water continuously and avoid popping salt tablets. Then long for winter’s cold fronts.

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28 TOP-RATED AC & HEATING SHOPS

Feeling toasty? Who to call for repairs and installations
 

Illustration: Mario Wagner