In: Furnace1

Why is My Furnace Making Noise?

There many reasons why your furnace may be noisy, but finding the exact reason why it is making noise and how to fix it can be challenging. Some problems can be fixed by yourself but some problems need an expert to be fixed.

If you hear your furnace making noise it could be a problem with the fan that cools down the furnace. This is caused by the fan bearings being worn out. So to be fixed the bearings will need to be replaced.

If the loud noise happens only when the furnace starts to turn on then this problem is called “delayed ignition.” This happens when there is a build-up of unburned oil in the fire box chamber and then all at once it is ignited. This problem is dangerous so it is best to call a professional to fix the problem. RSP Heating and Cooling is a qualified HVAC professional in Southern Illinois.

Whistling Noise

A whistling noise means there is a problem with the duct. It could be caused by gaps in the duct. Get close to the duct and see where the whistling is coming from. You should be able to hear where it’s coming from. It will be a small hole near the connecting point of the duct and furnace near the blower.

If the noise just started happening then it might be a clogged filter that can make the fan suck air from everywhere. To see if this the problem, pull out the filter and see if the whistling stops.

If the filter is filthy, it might be best to keep the filter out until it is replaced. This will help with the noise and the condition of your furnace. Just don’t forget to get it replaced ASAP!

Rattling and Vibration

If your furnace is rattling or vibrating then we have some simple solutions for you. Here is what you can do to stop the rattling:

  1. Add screws to any loose ducts
  2. Duct tape loose ducts or other equipment
  3. Place rubber or cork pads under the furnace (Use a pry bar to lift the furnace so you can slide something under it)

Motor Noise

If it sounds like it is coming from the motor, it may be caused by some bouncing. This can be solved by placing styrofoam under the squirrel cage. If the bearings are out then give RSP Heating and Cooling a call at 618-942-2424.

Banging When the Furnace Turns On

If you turn on your furnace and you hear banging, there are two possibilities. It could be “oil-canning” or an “ignition roll-out.” Oil-canning is when the duct work is flexing when the pressure changes. Ignition roll-out is a small “explosion.” Keep reading to find out more.

Oil-Canning Ductwork

This is a problem you should be able to fix yourself. Listen to if the banging is coming from the duct. If this is the problem then there is probably a weak spot in the ducts and they need support. This can be fixed by screwing a thicker piece of metal across and onto the weak spot.

Ignition Roll-Out

This problem is a lot less common but can be a big problem. It’s caused by a tiny explosion when you start the furnace or a flame that is too big.

First, watch the furnace start up and see if the banging is coming from a gas-ignition problem. Look into the furnace while leaving the doors on to see what is happening. If you can’t do this then listen to where the noise is coming from. Look to see if the furnace doors are shaking. If it does then turn on the furnace again but this time with the door open. If you see a bigger flame or it’s shaking then contact a professional. This is a dangerous problem and should be handled by someone who is licensed to do so. Newer furnaces will shut down if this is the problem.

Banging or Squeaking When You Walk on the Floor

Banging or squeaking when you walk on the floor near the furnace can happen. The duct could be on too tight or the metal panning is not nailed in correctly. This can be easily fixed by doing one of the following:

  1. Reinforce the duct with an oil-canning duct
  2. Rehang the duct
  3. Replacing it with a Thermo-Pan, a better quality sheet metal. It is resistant to fire and reduces noises for the furnace

We have only touched on the surface of furnace noise problems. If you are unsure of where the noise is coming from or how to fix it then call a reliable professional. RSP Heating and Cooling can help fix your furnace in no time! Give us a call at 618-942-2424, send us a message, or find us on Facebook!



One thought on “Furnace making noise?”
  1. Dorothy schoen

    My furance is whining when it shuts off.

Leave a Reply

Your email address will not be published. Required fields are marked *