Big energy savings over earlier central air conditioners is one more reason to install a new unit or replace an old one that broke. But you may want to give Amana, Goodman, and York the cold shoulder. All three brands logged the most repairs in our latest reliability surveys of more than 40,000 readers who bought a central A/C system.

Goodman, along with Rheem and Lennox was also among the more repair-prone brands of central heat pumps, which exchange hot air for cool air in summer and do the opposite in winter. The added complexity of these systems and the fact that they’re used for more of the year may help explain why 20 percent of them needed repair compared with just 13 percent for central air conditioners.

The surveys, from the Consumer Reports National Research Center, also show that fixing any central A/C system can be a real headache. Some 39 percent of subscribers who repaired either type were left without cooling for at least a day. Ten percent reported repeated repairs during the first year after installation, and 18 percent said their system broke down completely. What’s more, the roughly 30 percent who had problems shelled out $150 or more for the repair.

The good news: Choosing one of the more reliable brands in our survey can boost the odds that you will be comfortable. Here are some other steps that will help you minimize repairs and trim your cooling bill.

Hire your own installer. Our research showed a strong correlation between repairs and installation. For central A/Cs, 19 percent of systems installed by new-home builders failed compared with 12 percent installed by homeowners. The gap was even wider for heat-pump units, where 28 percent of the builder-installed units failed compared with 18 percent for owner-installed systems.

Keep it clean. Be sure hedges and plants are at least 2 feet away from the outside unit. Clean grills and filters monthly. Clear debris and dirt from condenser coils and check for blockages in the drain pipe.

Seal and insulate ducts. Up to 30 to 40 percent of energy can escape through leaks or when ducts aren’t insulated.