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Furnace Repair In Castle Rock

5 Noises Coming from Your Furnace and How to Fix Them

Various issues can make your furnace create loud noises. Scraping, banging, whistling, and popping can indicate a loose part, a cracked heat exchanger, or dirty gas burners. To prevent a gas leak from endangering your home and family, here are five loud furnace sounds you should know and how to fix them:

1. Scraping

If you hear a scraping noise from your furnace, it’s important to take note and investigate the source of the noise. It could signify that your furnace’s ball bearings are worn out or that the blower wheel has become loose. Either way, it’s best to turn off the heat and call a certified HVAC professional. Doing so can prevent further damage to your furnace and keep your home heated safely and efficiently.

2. Banging

If your furnace is making a loud booming or banging noise, it may be caused by a small gas explosion during an ignition delay. Gas can build up in the combustion chamber when the gas burners in the furnace do not ignite on time. If the gas burners are not igniting efficiently, this may indicate a clog or a gas pressure problem. Do not attempt to fix the gas burner without a licensed technician, as disassembling the heat exchanger or burners can cause a gas leak in your house.

3. Popping

The blower motor in your furnace turns on and begins circulating warm air throughout the ductwork in your home. If you hear a loud popping noise when the furnace is first turned on, it’s likely due to the expansion of the metal ductwork as the warm air comes into contact with it. Another possible source of the noise could be the gas burners in your furnace. Over time, sediment can build up on the burners; if this debris isn’t removed, a large amount of gas can collect and cause holes in the heat exchanger.

4. Rattling and Rumbling

If you notice that your furnace is vibrating, it is important to have a professional inspect it. Loose parts can cause vibration and, if left unchecked, can break other components in your furnace. A certified professional will have the tools and equipment necessary to fix the problem.

5. Shrieking

If your furnace starts making a high-pitched squealing noise, there is a problem with the motor. The most likely problem is a damaged belt. If you catch the problem early, it is easy to fix with the right tools and equipment. However, if you don’t catch it early, the problem can become much worse. Therefore, it is important to call a licensed contractor to repair the belt as soon as possible.


There are many different types of furnace noises, and each one can indicate a different problem. If your furnace is making any strange noises, it’s important to have a professional take a look at it to diagnose the problem and find the best solution. With some basic troubleshooting and knowledge of how your furnace works, you can often fix small problems yourself. However, it’s always best to call a professional for bigger issues.

CG Heating and Cooling is a licensed and insured HVAC company servicing Castle Rock, Parker, Highlands Ranch, and Westminster, Colorado. With over 20 years in business and NATE- and EPA-certified technicians, we have the experience to handle all your heating and cooling needs. Get in touch with us if you need furnace repair in Castle Rock! Call (720) 284-2849 now!