Summer is the most stressful time of year for heat pump systems. You probably rely on yours for most of the day to keep your home cool and comfortable, which means you’re putting a lot of stress on the system. The more stress the heat pump is under, the more likely it will be to develop issues of various kinds. If you want to mitigate these issues, you should know ahead of time what symptoms to look for that indicate a problem. One of the best ways to tell that your heat pump needs repairs is to listen for odd noises.
The air handler is the part of the heat pump that actually circulates air throughout the home while the system is on. It’s a powerful motor that rotates a large fan to blow air through the ducts. The air handler motor generates a lot of friction, so it has oiled bearings inside it to help things run more smoothly. Eventually, these bearings will start to wear down and the friction on the air handler will increase. If you hear a loud grinding noise coming from your heat pump, it means that the bearings in the air handler motor probably need to be replaced. If they are not replaced in time, the motor will overheat and burn out.
If your heat pump is making bubbling noises, as though something were on a low boil, you probably have air bubbles in the refrigerant line. That often means that there’s a leak in the line somewhere, which isn’t good news for the system. A refrigerant leak will slowly cripple the heat pump, sapping its output capacity as the refrigerant level in the system drops. Eventually, the refrigerant level will drop so low that the heat pump will not be able to operate at all. If you hear this noise, especially if you see fluid dripping from the system at the same time, call for repairs right away.
Perhaps the worst sound to hear while the heat pump is operating is the sound of it cycling on and off every couple of minutes. That is short-cycling, and it can destroy your heat pump if you don’t act quickly to stop it. Short-cycling is most often caused by electrical issues in the system, which throw off its operating rhythm. This cuts down on the heat pump’s capacity to cool, since it can’t complete a full cycle. The long term ramifications are far worse, though.
Short cycling causes the various parts of the heat pump to wear down at an accelerated rate, making the system much more prone to repair issues. If the issue goes unchecked for long enough, it can actually cut the lifespan of the system short by several years. Make sure that you call for repairs as soon as you notice this, or you may find yourself replacing the entire system years sooner than you would otherwise have had to.