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Noisy Furnace? Here are 3 Noises You Shouldn’t Ignore

You probably don’t often notice the gentle hum of your furnace as the blower turns on, or the minor pops that emanate from the air ducts. If you do, you can relax knowing these are normal sounds that let you know your furnace is working. If, however, your furnace becomes excessively noisy, contact your Denver HVAC professional right away. Loud or continuous noises should not be ignored, as they are a sure sign your furnace needs repair or maintenance. Quickly addressing the problem can avoid costlier repairs or replacement down the road.

3 noises that should never be ignored

1. Scraping Sound – The sound of metal against metal indicates a problem with the furnace’s blower wheel. Several issues could be causing this noise.

• A loose blower wheel is hitting the blower casing. If there isn’t too much damage to the blower wheel or the motor shaft, a professional can tighten the wheel so it is securely on the shaft.
• The blower wheel is broken and needs to be replaced.
• The motor mount broke and the whole assembly has dropped and is hitting the housing. (This is the most serious and expensive to repair.)

2. Loud banging or popping noises when the furnace turns on have two possible causes.

• Dirt on the furnace burners can delay the burners from igniting and cause gas to build up. This is serious because when the burner does ignite, it causes a small explosion (the sound you hear) that could crack the heat exchanger – a very costly repair. Regular maintenance can prevent the burners from becoming clogged with dirt, particularly if you have it done before you use the furnace each season.
• Expanding and contracting metal air ducts can also create that sound as the blowers turn on and off. This could be a sign that your air ducts are too small or flimsy, that vents are closed or that your air filter is clogged and needs to be replaced.

3. Squeaking or a loud whine can be caused by several issues that are typically not serious, but should be checked and corrected to avoid more serious problems down the road.

• The blower belt is loose, slipping or frayed and should be tightened or replaced.
• The shaft bearings need lubrication. Your technician will apply the proper lightweight oil to the port at each end of the shaft.
• The blower motor is malfunctioning and needs to be repaired or replaced.

Don’t wait for costly, inconvenient repairs! Contact IAQ today to schedule your regular furnace maintenance or to investigate a troubling noise!