The HVAC sounds most homeowners like to hear are the gentle whoosh of warm air flowing into rooms from the furnace in winter and cool air conditioning coursing through the vents in summer. However, these systems incorporate a number of components that may generate HVAC sounds that indicate something other than reliable indoor comfort.
If you’re wondering about some of the HVAC sounds you might hear from your furnace or air conditioner, here are some possible explanations:
- Popping or dull clunks inside the ductwork as the furnace heating cycle begins and/or ends. It’s a common sound caused by the expansion and contraction of metallic ducts as they heat up when the furnace cycles on and then later as the ducts cool after the furnace cycles off. This is normal in most cases as long as it is limited to those times only.
- High-pitched whistling when the air conditioner is running. This can be the result of pressurized refrigerant leakage from an evaporator or a condenser coil, or from the refrigerant lines that connect these components. Turn off the air conditioner and contact your HVAC contractor for qualified service to locate and repair the leak.
- Continuous rattling or other loud banging sounds. It’s usually some defective component that incorporates moving parts. This could include the fan motor or associated components in the indoor air handler or the fan in the outdoor AC housing. Also, a defective AC compressor motor is another potential suspect.
- A humming or clicking sound. An electrical contactor in the central AC system provides an extra jolt of high-voltage electricity to start the AC compressor. As wear accumulates over years, the contactor may begin to fail and cause a loud hum or clicking sound when the AC cycles on. Eventually, the contactor will no longer function and the air conditioner compressor will not energize. An HVAC technician can replace this vital component.
If you’re hearing abnormal HVAC sounds in the house instead of the gentle flow of heated or cooled air, contact the professionals at Jackson & Sons.