A furnace shouldn't be very loud when it is in operation. However, if your furnace is so loud that it is distracting, it might not only be annoying but the loud noise might also be a sign that there is something wrong with your furnace. The problem might be the result of a blower wheel, the heat exchanger, or the blower motor bearings.
1. Problems with the Blower Wheel
When a furnace has a broken blower wheel, you will hear metal scraping against metal and this can create a very loud sound. As a result, the furnace will need to be turned off so you can then have the broken blower wheel replaced. Fortunately, this is not a very expensive repair.
The blower wheel might also become out of balance. If this is the case, you might hear your furnace shaking. It might be because a piece of paper was sucked into a return air duct. If it is not corrected quickly, you might start to see other problems with your furnace. If something isn't sounding right, you will always want to contact a qualified furnace service technician.
2. Cracked Heat Exchangers
If you often hear a clicking noise, this could be the result of a crack in your heat exchanger. The routine heating and cooling that happens with your heat exchanger can cause cracks to eventually form. The clicking comes from the metal rubbing together as the heat causes the metal to expand a little bit.
A cracked heat exchanger needs to be corrected immediately. The crack in the heat exchanger can cause heat to be released into your home and can cause carbon monoxide poisoning.
3. Blower Motor Bearings
If you hear a high-pitched squeal, this might be the result of the bearings wearing out. The bearings are a component in your furnace that can last a very long time. However, if the blower wheel was unbalanced or if the furnace was overheating, this might cause the bearings to wear out prematurely.
The motor becomes hot when it tries to turn but is not able to because of a blockage that results from worn-out motor bearings. You may need to have the blower wheel, blower motor bearings, and the capacitor checked to make sure that your furnace lasts a long time. Regardless of the cause, an unusual sound should always be investigated so your furnace does not fail prematurely.
Contact a local heating service to learn more.