One of the best ways of knowing if your San Diego heating contractor is good is by asking around. People know people and a friend or relative will give you an insight into one of the contractors they might have encountered. A company with a bad reputation will always trigger a flurry of bad reviews to go around. The same goes for good contractors. If they are good, word will go around of how well organized they are or how well they provide their services. An alternative is to call the company direct and ask for a referral. Most of the companies if not all, will always give you a referral since if they do not, you might suspect something. You can even visit the referral if they do not live far-off and see what job was done for them.