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A Hissing Sound from Your Air Conditioner: What It Might Mean

We are getting closer and closer to the time when you’ll need your air conditioning system working steadily to provide your family with pleasant indoor temperatures. As the cooling system starts its regular operation for the middle of the year, make sure that you pay close attention to unusual sounds coming from the cabinets. This is one of the ways that a refrigeration device like an AC warns that something is wrong with it that requires the attention of professionals.

One of the common warning sounds from an air conditioner is a hissing, like gas escaping. We’ll look into what this might mean.

Brief hissing sounds

Your air conditioner will sometimes make hissing sounds as part of its regular operation. The expansion valve, which lowers the pressure of the refrigerant gas as it moves from the condenser coil, creates brief a hissing that lasts only a few seconds. If you hear periodic hissing and don’t notice other signs of problems with the AC (a drop in cooling capacity, ice along the evaporator coil) it’s usually nothing to worry about.

Sustained hissing sounds

This, however, is something to worry about. There are a number of different causes for continuous hissing noises coming from an air conditioner. The most common is that holes have opened along the copper refrigerant line, allowing the high pressure refrigerant gas to leak out. Loss of refrigerant will not only lower the cooling power of the AC, it can cause damage elsewhere to the system as the pressure levels decline. The leak could also be in the compressor valve, which is designed to control the pressure levels of the refrigerant.

Worst of all is when the hissing sound is due to a malfunction in the compressor itself: the pressure levels inside it are rising too high. Permanent damage to the compressor is one of the most expensive repairs that an air conditioner may need, so get on the phone right away to have professionals look into the problem and prevent it from getting worse.

Need air conditioning repairs? Call Red Rock Mechanical LLC in Burlington, VT.

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