The Fan On The Furnace Is Very Loud

Furnace fan motors can and do breakdown. They make different noises so I will list those noises here and let you know what is happening with your furnace.

Fan Makes a Loud Rattling Noise All The Time

This normally indicates something is wrong with the blower wheel. It is off balance either from throwing a balancing weight or breaking welds and crimps. If the blower wheel contains a piece of paper, duct tape or debris buildup this can throw the wheel out of balance and this out of balance is what is causing the noise.

The Fan is Just Too Noisy

The fan making too much noise is caused by a number of things:

  • Very low end furnace with no sound dampening insulation in the blower compartment
  • The return air register is a stamped type (low end) and it is too small
  • The blower speed is set on the wrong speed
  • Concrete or ceramic tile under the furnace cabinet bouncing noise back into the home

All these things can be fixed in a number of ways. Give us a call and we’ll come to you and let you know exactly what it is going to take to give you some peace and quiet when your furnace turns on.

The Registers in Each Room are Whistling

This is from too much air going through too small a space. Are all the registers open? The blower speed could be set too high. The ducting could be too small for the amount of airflow.

There is a Rattle in One of the Registers

This is normally from a defective register or a dampener just inside the ducting. Most register rattle can be handled by taking the register off the wall and crimping the offending piece or, if it is from a dampener, fixing the dampener in a single position.

Screeching Noise From the Motor

  • The furnace blower wheel has broken free or is loose scraping the side of the blower assembly.
  • The bearings are worn out on the blower wheel.
  • The windings in the motor have failed.
  • If this motor was just installed check to see if both the high speed and the low speed are coming on at the same time. This can be from a burnt relay or a miss-wiring. If this is the case the motor will only last a matter of minutes before burning out.