Noises sometime happen in the outdoor compressor, indoor air handler, or the ductwork!
Air Handler Makes Loud Annoying Sounds: screeching, grinding, and buzzing.
Is your Air Conditioning air handler screeching or grinding sounds? Though many air handlers have direct-drive motors, some older systems might be belt-driven. Squealing noises from a belt-drive air handler typically happen when the belt that links the motor to the blower slips. Most of the times, the belt is poorly aligned or used and requires replacement.
If a direct-drive blower is squealing or making a grinding sound, shut down the system and– unless you’re an accomplished do-it-yourselfer– call an HVAC specialist– the motor’s bearings are probably exploded. If you can handle this type of work, you can buy and replace the motor.
Air Conditioner air handler is ringing noises. Do you detect a ringing noise when you turn on the thermostat? The only thing that comes on in your home when you switch on the thermostat is in the air handler and fan relay or heating system. Attempt turning the thermostat HEAT/COOL switch to OFF. Then switch the fan switch from VEHICLE to ON. The fan (just) should begin. If the air handler makes a buzzing sound, it probably has a bad fan relay or, more likely, blower fan.
Outside Air Conditioner Compressor Makes Noise.
Are your outside compressors often make ringing, humming, or grinding sounds?
If the outside Air Conditioner system makes a ringing noise, as though it wishes to turn on but cannot, the run capacitor might be defective. If that capacitor spoils, the motor will get too hot when it attempts to switch on, however, can’t get started. When the engine gets too hot, a thermal overload switch will shut it off. When it ringings, quickly push through the grille with a long screwdriver or stick to try to spin the fan clockwise (be careful!). If it starts turning and spinning, it will run for one cycle but then stop working again. This shows that the capacitor is bad and has to be changed.
Air Conditioner compressor hums. If the outside compressor vibrates when you modify the thermostat to COOL, the problem could be the low voltage transformer on that unit– something that would need to be checked by a pro.
Air Conditioner compressor was grinding sound. With time, the bearings in the motor can wear. The result is a grinding noise and, in most cases, the motor will get too hot and shut off. When this occurs, it’s maybe time to buy a new engine. HVAC System Pros
Noisy Ductwork
Numerous heating/cooling ducts are metal, so they conduct sound rather readily from the air-handling system to your spaces. To break the conduction of noise, you can have a heating contractor insert flexible insulation ductwork in between the heating/cooling system and the metal ductwork.
