Your HVAC system may start making rattling noises after a few years of running smoothly.
The noise can be attributed to a number of moving parts inside various components of the system. Once you observe a noise coming from the HVAC system, you should not start tinkering with the system unless you are aware of how it functions. It is always advisable to call an HVAC expert to look into the issue.
Three Main Components
There are three main components of an HVAC system – the outdoor compressor and condenser unit, the indoor air handling unit, and the duct work used for carrying air to various spaces. Any of these components can become loose or wear down and start generating noise.
The outdoor unit is comprised of the compressor and the condenser. The compressor contains a large motor which runs the unit and makes a loud sound. The motor also causes heavy vibrations in the unit which are dampened by the vibration mounts. After a certain period of running, the vibrations can loosen the mounts and other parts of the compressor unit and these loose components can start making noise. The vibrations are more frequent when the compressor starts up or stops. If you notice that the rattling noise is louder during start-up and stopping, check for loose hardware.
Air Handler Unit
The air handler unit may also start to make rattling sounds during operation. The air handler unit includes a motor and fan which circulates air over the heating or cooling coils of the system. The air handling unit may start rattling due to excessive vibrations generated in the compressor and condenser unit. The cause of the noise can be identified by listening closely to the air handling unit. If the noise is louder at the compressor unit than the air handling unit, the problem lies with the compressor unit. In newer systems the compressor cuts-in and out depending upon the load and the air unit continues to operate. You should listen for noise when the compressor has cut-off to locate the source of the noise.
Rattling noises are also common in window unit air conditioners where the compressor, condenser, and air handler are installed together in a common housing. The most common cause of noise in a window unit is worn down bearings and loss of lubrication. The compressor is generally a sealed unit and the component most likely to fail is the motor. It is advisable to have a noisy motor replaced as it can tend to become a continuous source of irritation. The other components that can contribute towards noise are the two fans – one at the front and another at the back of the window unit. The fan blades may become loose and start rubbing with the housing which may cause a lot of noise. The fans can be easily replaced for noise free operation.
St. Louis Air Conditioner Repair
Contact Air Excellence Heating and Cooling to identify and resolve any HVAC problems you are having. Call us today at (636) 980-0998!