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Gas Furnace is Making Too Much Noise - Richard, my gas furnace makes a lot of noise when it is running and it is somewhat annoying and sometimes bothers me when I am sleeping. It is installed in a closet close to my bedroom. What can I do to fix this gas furnace that is making too much noise? I’m growing to hate my noisy gas furnace. Jenny
Jenny, sorry to hear about the noise your gas furnace is making. I know an overly noisy gas furnace can be irritating. All gas furnaces make some noise when operating and we can break it down into three different noises. Depending on which noise your furnace is making will depend on a fix to your furnace making too much noise.
Gas Furnace is Making Too Much Noise | Diagnosis and Repair
The first thing is the gas burners. A lot of inshot gas burners make a noise when they are burning the gas. Additionally, unless you have a standing pilot gas furnace which is an older type of gas furnace and not typical in the average home today, your furnace will have an induced draft or forced draft motor to properly vent the combustion gasses and give the combustion chamber combustion air.
Consequently, fuel needs air to burn. After the combustion process is complete you need to vent the dangerous gasses outside. The forced draft motor or induced draft motor helps this process. Lastly, those two things can cause noise all in themselves. However, there is another thing that can cause noise from a gas furnace. That is the blower motor inside the gas furnace that blows the hot air through the HVAC system ductwork.
Gas Furnace is Making Too Much Noise | Diagnosis and Repair
So to recap there are three different things that will cause your gas furnace to make noise:
- The sound the burners make when burning the gas
- The induced or forced draft motor (you have either of the two)
- And the blower inside the gas furnace that blows the air through the ductwork.
For the gas furnace making too much noise, I would first advise you to call an HVAC professional and have them give the furnace thorough maintenance service to make sure there is not a bad bearing or something in one of the motors making too much noise. Sometimes a little oil will stop the noise if the motor has a port for oil. There are some motors that do not require oil. However, if you have one that does a periodic maintenance service technician should take of it.
Caution | Gas Furnace is Making Too Much Noise
I would caution you not to block any vents or anything on the door that allows air to get to the gas furnace as the furnace needs fresh air to work properly. Again, do not block anything that would restrict the air from getting to the burners. Furthermore, any gas furnace needs combustion air.
Additionally, an allowance for this combustion air was made when the gas furnace was installed. If you block this off to reduce the noise then your gas furnace will not operate properly and it could be dangerous.
The HVAC professional may not be able to easily solve your problem aside from the maintenance service I mentioned above. The blower will make noise if the ductwork is undersized. This will be a costly fix if that is the problem. You will need to have new ductwork installed. The correct size of ductwork.
Burner Noise Gas Furnace is Making Too Much Noise
The burner noise and the induced or forced draft motor noise is hard to fix. It may require some additional ductwork installed to pull in combustion air from the outside. That way you can completely block off the vents on the closet door.
That can be expensive and needs to be done by an HVAC professional. It is very important to get the proper amount of combustion air. Finally, combustion air is needed by the furnace for it to operate properly and safely.
Conclusion
There may not be enough room to run this ductwork and in that case, you may be stuck with the noisy gas furnace. At least until it comes time for a new gas furnace and then you can look at having the new gas furnace moved to another location away from the bedrooms. Lastly, good luck, and I hope this helps the gas furnace making too much noise Jenny!
Gas Furnace is Making Too Much Noise | Diagnosis and Repair
We have a new furnace professionally installed but when it starts blowing the hot air into ducts it makes a BOOM !!! sound. Before that there are all sorts of knocking sounds. Now lately we hear a sound like large bird wings fluttering, and it seems to be coming from the chimney, we can hear it through a return air register in our dinning room. It sounds really weird, like a burst of air or when a fan blades flutter in wind. It wakes me up 2-3 times a night. Last night I heard it at midnight, then at 4 am, then when I was awake the sound came again at 10 am. I probably didn’t hear the ones in the early morning because I was dead tired and fast asleep. But they could be coming in the same intervals as the furnace coming on. So we are shutting down the furnace completely and will use space heaters for the night until we test all this. Any other ideas ?
The company that installed the system needs to be called and let them check it out for you. Most respectable contractors give you a warranty on workmanship and I am certain they would be happy to look at it for you. And hopefully, resolve the issue for you.
Make sure you have adequate return air in your system. 200 in.² per ton. I have a 5 ton HVAC system. It was designed in the late 80s and had only an 18 x 25 return. I changed that to a 20 x 30 filter back grill. This squieted it down, but still too loud. I added another 20 x 20 grill and now it is running good and according to specs. Your system needs to breathe, not enough air and it will run loud and burn out parts much faster.
Yes, absolutely, proper duct size is very important.