Your home's HVAC system should be very quiet for the most part. You may hear the hum of the furnace or the outdoor compressor as it runs, but other than that, it should be fairly quiet. That is why it is normal to be concerned when you are hearing odd sounds when the HVAC system is in use. Follow these steps in order to get to the bottom of it.
Check The Air Filter
One of the first things you should do is check out the HVAC system's air filter. It is possible that the system is struggling to push air through a filter that is absolutely clogged. This can cause the HVAC system to sound almost as if it's wheezing because the air is struggling to get through the filter due to all the debris that is stuck in it. A dirty filter can also cause a rattling sound since the filter can start moving due to the air pressure forced against it.
Try swapping out the filter to see if it improves your problem. You may be surprised that such a simple swap can fix it and make the noise stop. If not, you've at least done an important step in maintaining your HVAC system and providing cleaner air to your home.
Check The Blower Motor
One part that is constantly moving is the blower motor since it is used for heating and cooling to push air through your home. If you hear squealing in your home, it's possible that it's due to the moving parts of the blower motor. It may need some lubrication to get the part rotating smoothly and to eliminate that squealing that you hear throughout the house.
Check The Igniter
Do you hear a loud bang every time the furnace turns on? This is a problem that can be due to a dirty igniter. What is happening inside the unit is that gas is being released to be ignited and initiate heat being released. Unfortunately, a dirty igniter can cause problems with this process. As the igniter struggles to get started, more gas will build up in the furnace. When the igniter finally works, there is so much gas inside the furnace that you hear a loud bang. This is a small explosion caused by all the built-up gas.
Consider having an HVAC technician come out to your home to repair or replace the igniter. This simple swap could be all you need to prevent that loud bang from happening again in the future.