It is never a nice sound to hear the heating and cooling device turn on, and then off, and then on, and then off again. If it keeps turning on and off again care about that, then that means the cooling machine is short cycling. The a/c can short cycle for multiple reasons. Thankfully, I have quite a bit of expertise when it comes to HVAC, so I could easily diagnose the concern myselfâ€¦ One of the reasons a cooling device might short cycle, is because the air conditioning machine is too big for the home. An a/c that is too big you would guess would be a nice thing, but easily the short cycling causes the HVAC device to have a much shorter lifespan because it cools the house easily too suddenly. I have had our central A/C for years, and the short cycling is recent, so I knew that wasn’t the problem. Another reason that your A/C device might short cycle is because it is clogged. I kind of wondered if this was our issue, since I had forgotten to change the air filter. My HEPA air filter by now was easily quite dirty, and so I went and pulled it out and put a current HVAC filter in. Sure enough that was the problem. It is dangerous to not change your HVAC filters often enough, because it causes the A/C to heat up and labor harder in an attempt to cool your home. I am cheerful I caught this now, before it became a bigger issue.