This time of the year, the weather in Houston feels very much like a rollercoaster rapidly plunging deep into the frigid chill and then quickly rising back to t-shirts and shorts. Houstonians are experts at the practice of dressing in layers. I leave the house in a t-shirt, long sleeved shirt, and a jacket. By mid-morning, I have shed my jacket, and after lunch, I leave my long sleeved shirt in the car. During the afternoon, the process is reversed such that I am back in my jacket by the time I take the dog for her evening walk.
But what does all this rapid temperature change mean for my heating and air conditioner? Will it cause damage? Why does it sometimes shut off when I am changing between the two?
I am relieved to know that there is no real risk that I will damage my system trying to stay comfortable. However, the rapid changing back and forth could cause your system to lock-up and shut down.
When you are cooling, the outdoor unit is on. When you change your set point temperature higher to shut it off and then immediately dial the set point temperature lower it would call for cooling again and cause the compressor to lock-up. Something similar happens when you do the opposite, the equipment will attempt to come back on but the compressor will probably lock-up because the pressure has not equalized in the system. When the compressor locks up, it can draw a high amp rate causing the system to blow a breaker.
If your system does shut off while making adjustments back and forth between the heat and air, first check your fuse or breaker. You may also need to check your unit’s outdoor disconnect as some have a separate breaker as a part of the unit. To avoid the situation all together, it is a good idea to get in the habit of switching your system to off for five minutes before changing from heat to air or vice versa.