Your furnace is responsible for keeping your home warm through the chilly winter months. If you are hearing strange noises coming from the furnace, investigate immediately and find out whether it is a symptom of a deeper problem that could leave you shivering. Furnaces can make several noises to indicate problems, and the type of noise is often enough to give you a basic idea of what is wrong. Make repairs before the furnace stops working entirely to save you some discomfort.
A squealing sound coming from the furnace is hard to ignore. A squeal can indicate a problem with the blower belt. If the belt is worn or is improperly aligned with the fan, there will be noise. The noise will stop if the belt finally breaks, but so will the blower and the circulation of warm air. Remove the panels and check the belt for wear or misalignment and replace or adjust as necessary. This is generally a repair you can do without the help of a professional by following directions found in the furnace manual.
Motor Shaft or Bearings
If the squeal accompanies a grinding sound in the furnace the problem may not be the belt. Instead, it may indicate a problem with the blower fan’s motor or, more specifically, trouble with the bearings or the motor’s shaft. They may be worn out and the motor, may require replacement. If the motor has lubrication ports, it may require only the addition of oil to make the problem go away.
The furnace is covered with thin metal panels attached with small screws. If the screws loosen and make the panels loose, the result can be a rattling sound when the furnace is running. The rattling of these loose panels is easily remedied. Find the loose screws and tighten them to make sure there is no unnecessary movement in the metal housing around the furnace.
Pilot and Burners
A deep rumbling sound in a gas furnace can be unnerving but it may be a common problem. If you notice the sound mainly when the unit is not running, it indicates a poorly adjusted pilot light. If it is more noticeable when the unit is running, it is the result of dirty burners. Call a technician out to check the pilot adjustment and burners to get them functioning properly and safely.