Blower Fan Motor Noise

There is more than one possible cause for a noisy air conditioner.

Blower fan motor noise.

The sounds happen less when blower is on higher settings and all the time on lower speeds. If your interior ac heat fan blower motor is making noise like a card in a bicycle spoke then you probably just need to clean. If you hear a loud rattling noise it could be a minor issue like loose stones or debris that s caught in the condensing unit. The blower motor is a small rotary motor that drives a fan sitting behind your vents pushing hot or cold air through them at varying speeds depending on your selection.

Installing an acoustic rubber pad under the furnace specially if it is sitting on concrete will damp the vibration you hear through the pipes although the blower fan and motor are the most obvious parts to check take a look at the complete unit. Pipe brackets burner parts cold air returns access panels into the burner chamber and blower chamber or even the plenum itself could be loose. During blower operation this debris causes the blower motor to be noisy. Remove the old fireplace air blower.

Even though it s in a housing it lives in the engine compartment so it s not unheard of for foreign objects to get sucked into and wrapped around or caught in the fan. Once it is safe to touch examine the motor and look for any obvious signs of wear or breakage. Sometimes during blower motor operation you might hear excessive noise. In that case buy a complete kit.

Blower motor mount squirrel cage plenum filter too small or the furnace itself vibrating. However if the motor doesn t run at all chances are it has a bad temp sensor or speed switch. Quiet a loud blower motor. Sometimes this noise is not due to a blower motor problem but occurs because debris is caught inside the blower assembly.

The sounds happen in cold or humid weather and especially when hitting bumps in the road or slamming on the brakes. We bought just the blower for the 14 year old heat glo gas fireplace shown here. Humming sound a humming sound is one of the most common blower motor noises reported by home owners. This debris often works its way down into the hvac system from the vent opening under your windshield wipers at the base of your windshield.

Your first step after noticing this sound should be to turn off your furnace s motor and let it cool down.