Common Causes of Heater Sounds
If your heater is making an unusual sound, it may be due to one of these common problems:
- A dirty air filter that needs to be changed
- Loose air ducts that need to be secured
- Blower fans that are bent or loose
- A heat exchanger that has cracked
- Fan belts that wear out
- Leak in the gas or refrigerant line
Each one of these problems has a specific noise associated with it. If you can describe the noise you hear, we can pinpoint the problem and help you get it solved quickly.
Heater Banging
Loose ductwork can cause a banging sound. The thin material that ductwork is made of can expand and contract as temperatures change. The metal creates a banging sound when this happens. Securing your air ducts can prevent banging if that’s what the issue is.
Heater Whistling
Whistling is often an indicator that the airflow inside your system is impeded by something. There may be a blockage that is preventing air from traveling between the different parts of your heater. Other times, the whistling can indicate that the refrigerant line or gas line in your heater has a leak.
Heater Booming
A loud boom from your furnace can be startling. This loud noise could be caused by a delayed gas ignition. This occurs when gas in the furnace builds up instead of immediately igniting like it’s supposed to. When the gas finally does ignite after a delay, a mini-explosion happens, resulting in the loud boom. This can be harmful to your furnace and warrants immediate repairs.
Heater Knocking
If your heater is making a knocking noise, one of your fan blades could be bent. As the fan spins around, it knocks against nearby surfaces. It’s also possible that one of your fan belts broke and is slapping against other surfaces as the fan spins around.
Heater Rumbling
It’s normal to hear a gentle swish sound as air moves through your heating system. But if the heater turns off after a heating cycle and begins to rumble, that is a bad sign. There may still be oil or gas in the combustion chamber that is continuing to burn. As it burns, it makes a rumbling sound.