Spring is in full bloom, and chances are you’ve already run your air conditioner regularly this year. In a few weeks, you’ll need to run it every day to keep your home cool and comfortable. If there’s a problem with your system, now is the time to have it diagnosed and repaired, before the first real heat wave hits. Otherwise, you might experience an unexpected breakdown in the middle of the hottest day of summer, forcing you to scramble before your home turns into an oven.