The occasional ding, squeak, bump or pop emerging from your furnace or ductwork isn’t a big deal. But if your furnace is making regular or recurrent noises, and if those noises appear to be getting worse over time, it could be a real cause for concern.
There are three sounds in particular that you should watch out for, and if you’ve been hearing any of these you should have your HVAC system inspected for damage as rapidly as possible …
1. Loud Metal Scraping Sounds
If you hear scraping, screeching sounds of metal-on-metal it’s possible something has happened to the blower wheel, such as:
- The wheel has come loose from the motor shaft and is scraping against the inside of the blower casing. This is usually a repairable problem, unless you let it go on long enough to cause real damage to the wheel.
- The blower wheel is broken and will need to be replaced.
- The motor mount has snapped and the entire blower assembly has fallen into its housing. This is a costly repair and would be a worst-case scenario, for sure.
Blower wheel problems are nothing to fool around with. If you hear persistent metal scaping sounds, you should shut off the furnace immediately and call in a repair professional right away.
2. Loud banging noises when the furnace kicks on.
Banging noises have two possible sources, the second of which is far more serious than the first:
- The expansion and contraction of your ductwork as the heat circulates through it. If this happens a lot, your ductwork may undersized or constructed from substandard materials, or your air filter may be clogged and need replacing. The latter you can take care of yourself, the former might be an issue you’ll need to address in the future, if the banging noises keep getting louder.
- The burner in the furnace is caked with dirt and grease. Dirty burners ignite inefficiently, leading to gas buildup that causes banging noises when the furnace finally does fire up. If these mini-explosions continue it could eventually damage the heat exchanger, which could cause dangerous carbon monoxide leaks and ultimately condemn your heat exchanger (an expensive part to replace) to the scrap heap.
Loud banging noises shouldn’t be ignored, and if you hear them you should cross your fingers and hope it’s just the ductwork.
3. High-pitched squealing noises.
There are three likely explanations for a squealing, whining furnace:
- The blower belt is fraying, slipping or has come loose. If it is damaged it may have to be replaced, which is a relatively simple procedure for a trained HVAC technician.
- Shaft bearings may need oiling. For an expert technician, this is a cheap and easy repair.
- The blower motor has begun to malfunction and may need repairing or replacing.
Squealing issues might not be as urgent as some others, but they will get worse if you don’t take steps to address them quickly.
ABE: Your Furnace Inspection and Repair Experts
If you arrange for an annual fall inspection of your heating system, a certified HVAC technician should be able to detect developing problems before they get out of control.
At ABE Heating and Cooling we are strong advocates of preventive medicine, and if you request a maintenance and inspection visit from us you can rest assured we’ll cover everything from top to bottom, leaving no stone unturned in our efforts to sniff out potential trouble.