Your heat pump will never master the human tongue, but it still speaks in a language all its own. Whenever there's a problem with your heat pump, you'll likely hear about it through the noises it makes. Different problems can produce different types of sounds, so take note of the following if you decide to do your own troubleshooting.
Squealing noises often indicate a blower fan belt that's in dire need of replacement. Fan belts can develop a glazed surface due to ordinary wear or improper contact with the pulley surface, leading to constant squealing noises during operation. Stress cracks can also form as the rubber material dries out due to age.
If your heat pump lacks a drive belt for its blower fan, then the problem may lie with the blower itself. Failing blower motors can develop squealing sounds while running.
One important thing about heat pump refrigerant is that it doesn't get used up like ordinary fluids. Once it's in your heat pump, it'll stay there unless there's a leak somewhere in your system. Heat pumps and other HVAC systems are notorious for developing pinhole leaks that allow refrigerant to escape. Escaping refrigerant is often accompanied by a faint hissing sound that's sometimes difficult for the average person to detect.
If you do hear hissing noises somewhere within the heat pump, shut the unit down immediately and call for a professional to perform a comprehensive inspection of your HVAC equipment.
If your heat pump is running low on refrigerant, it may produce a low-pitched gurgling sound as it attempts to cycle through what's left of its refrigerant. It's never a good idea to run a heat pump on low refrigerant, since doing so could damage the compressor and other components within the unit. If you hear gurgling noises coming from your heat pump, turn it off and call your HVAC technician as soon as possible.
Grinding noises can mean any number of terrible things for your heat pump. A lack of proper lubrication or the use of low-quality lubricant can cause bearing damage in a blower fan motor, resulting in constant grinding and eventual failure. Moving parts contaminated with dirt, grime and metal shavings can also produce grinding noises. Direct metal-on-metal contact of certain components, such as a misaligned blower fan rubbing against a metal case, can also cause grinding.
if you hear a high-pitched shrieking noise coming from your heat pump, it's likely due to a failing compressor. A bad compressor cycling contaminated refrigerant can produce unpleasant shrieking noises during operation. Running your heat pump in this state could lead to further damage, so it's best to simply shut the unit down and wait for a professional to make repairs.