Consumer Reports' survey of more than 40,000 subscribers reveals some systems have been much better at keeping their cool than others.
Contractor Tim Mosher says it is important to take good care of a central air conditioning system.
"The preventative maintenance in the beginning of the season is better than having to have a serviceman come out during a heat wave," Mosher says.
And Consumer Reports says carefully choosing an air conditioning system can help you avoid service calls as well.
Its latest product-reliability survey shows some central air systems have been significantly more repair-prone, Amana, Goodman, and York.
"In the past six years, close to one in five of these systems needed repairs. That's a lot," said Dan Diclerico from Consumer Reports.
Consumer Reports' survey also shows how inconvenient repairs can be.
Ten percent of those polled said they needed repeated repairs in the first year. Eighteen percent reported their system broke down completely, 39 percent lost AC for at least a day.
"About 30 percent who had problems had to pay $150.00 or more for the repair," DiClerico said.
To prevent having to call a repairman, Consumer Reports says invest in a more reliable brand, including ones from American Standard, Rheem, or Trane.
And Consumer Reports suggests that plants and hedges should be at least two feet away from the air conditioning unit.
Also, clean filters and grills monthly, and be sure to seal and insulate every duct.
"Up to 30 to 40 percent of energy can escape through leaks when ducts aren't insulated," says DiClerico.
Another energy saver, use a programmable thermostat and set the temperature higher when you're out of the house.
Consumer Reports' survey turned up more interesting information. Homeowners who hired the installer themselves versus those who let a home builder do the hiring had significantly fewer repairs.
And once your system is installed, Consumer Reports says it's important to get it inspected by a professional at the beginning of every cooling season to avoid repair problems.