Returns are quiet; vents are making the noise. I think the furnace is also making the noise but I can't tell for certain when I'm right on top of it
However, what i found is that if I remove the filter and leave the front furnace door open (which exposes the wires, etc.) the noise is like 99% reduced. If you strain you can still make some resonance out, but just barely.
Maybe it's not a furnace issue but some type of ducting/air-flow issue? Not enough/too much air based on existing duct sizing?
My mid-efficiency furnace also gets weird harmonic noises occasionally that is equal throughout the house. It is 100% the metal louvres in my return air grills. Sometimes they start humming and need to be bent a little or pulled out if the kids have hit them with something.
That was my issue with a couple air return ducts closest to the furnace.
For years they sounded like a turbine engine and I thought it was "normal" until one day I made contact with the grill and the noise went away.
I've just place a magnet strip on the back side of the grill to stop the vibration and it fixed the issue.
Not sure if this helps anything but I replaced my 24 year old carrier furnace last month with a stage 2 goodman, the old furnace was crazy loud when trying to start, and I had to replace it because one of the heat exchange cracked. Anyways the new furnace is so quiet I can hardly hear anything. Not sure if this is because I was so use to the old one which was loud.
Not helpful but my plumber said try to avoid going high efficiency as much as you possibly can because they suck and break way more often. He also agreed with using mid to low filtration filters and definitely avoid high filtration
Z32 TT
1996 Integra - winter beater with studs - RIP (deer)
2002 WRX - to be sold
2010 sti - winter
Measure your return air size and read in the installation manual to see if it meets the spec for the size of the furnace. Also buy a bucket of duct sealer and go to town on all the joints.
On some furnaces, you have to redo the return airs to a dual inlet to a prefabbed return box that the new furnace sits on to get the airflow the machine wants at full tilt.
I've observed that some companies use silver silicone to seal ducts, then when one edge of it comes free it becomes a noise maker like a kazoo.
I may as well add that it's important to check the grading of the furnace, there are some models that can have premature heat exchanger failure if the furnace is tilted towards the back, since condensate won't drain totally from exchanger when the drain pan is at the front of the furnace.
Measure your return air size and read in the installation manual to see if it meets the spec for the size of the furnace. Also buy a bucket of duct sealer and go to town on all the joints.
On some furnaces, you have to redo the return airs to a dual inlet to a prefabbed return box that the new furnace sits on to get the airflow the machine wants at full tilt.
I've observed that some companies use silver silicone to seal ducts, then when one edge of it comes free it becomes a noise maker like a kazoo.
I may as well add that it's important to check the grading of the furnace, there are some models that can have premature heat exchanger failure if the furnace is tilted towards the back, since condensate won't drain totally from exchanger when the drain pan is at the front of the furnace.
can you elaborate on the prefabbed air return box? my furnaces are just on the ground using the return air system that was with the original furnaces (from like 1992). one comment i'd read previously is return air setups for old mid-efficiency furances could cause harmonic issues with new furnaces because of higher fan speeds.
I had the installer back again today (6th time in a month, but at least it's free under warranty for whatever good that does) .... as usual this guy just ho'd and hum'd and looked at the filter. I demonstrated how opening the furnace door made the high pitched noise disappear and he's like 'yea, you're just dumping out a lot of air now, doesn't mean anything'.
Probably going to go find another company and pay out of pocket, but would like some ideas so I can speak to them first to see if they sound like they'd be wasting my time or not.
The harder the bearing the noisier it tends to be. Softer sometimes means you have to replace it more often.
Same thing supposedly goes for high performance brakes, imperfect and lower quality durability means that it doesn't squeak. Used to be true for gasoline too, add lead imperfection - no more knocking.
On a completely unrelated side note:
The quest for quiet has had several roadbumps. There is no clear winner as some people can't hear high frequencies anyhow.
Could be the covids too, much like how it blocks taste, it seems to enhance tinnitus and ringing in the ears.
Last edited by ZenOps; 11-21-2022 at 06:09 AM.
0.5 gram microsd delivered by 12,000 pound combustion vehicle and driver.
What motors did you get and I assume that's all under warranty?
Whatever the Lennox furnaces came with from the factory - maybe the bearings were shot on the original ones out of the box, who knows, I'm just happy it solved my issue
not sure if anyone experienced this before when installing a brand new furnace, but after running smooth for 2 months, one morning it stopped working. As I go check it out, I noticed it tries to start but then stops. A couple of clicking sound and no ignition. The error code shows it is dL (idle) mode, so no alarm there. Finally had to call the installer back to check it out, he says the controller board was shorted and it blew the fuse on it. The first time he turned it back on shortly after replacing the fuse, it sparked and blew the fuse again. He looked at everything, an did not find any shorts or wires in the wrong places. Could explain what happen, but in the end, replacing the fuse one more time did the trick and it has been 2 weeks without any issues.
Just thought I share to see if this is just an unusual anomaly. or a common issue with new furnaces.
not sure if anyone experienced this before when installing a brand new furnace, but after running smooth for 2 months, one morning it stopped working. As I go check it out, I noticed it tries to start but then stops. A couple of clicking sound and no ignition. The error code shows it is dL (idle) mode, so no alarm there. Finally had to call the installer back to check it out, he says the controller board was shorted and it blew the fuse on it. The first time he turned it back on shortly after replacing the fuse, it sparked and blew the fuse again. He looked at everything, an did not find any shorts or wires in the wrong places. Could explain what happen, but in the end, replacing the fuse one more time did the trick and it has been 2 weeks without any issues.
Just thought I share to see if this is just an unusual anomaly. or a common issue with new furnaces.
I wouldn’t harbour any hope it’s going to stay running for any length of time.
All these furnaces seem horrible for reliability. I would suggest everyone have alternate means of heating your home in an emergency. I keep two of the 1500W electric heaters and figure those plus two gas fireplaces and a small section of heated flooring should get us through an emergency if we have one.
All these furnaces seem horrible for reliability. I would suggest everyone have alternate means of heating your home in an emergency. I keep two of the 1500W electric heaters and figure those plus two gas fireplaces and a small section of heated flooring should get us through an emergency if we have one.
That and the furnace repair biz you're about to buy...
If the furnace is only slightly annoying, it might be worth it to just sound deaden the room with something like Sonopanels. Roughly the same cost as an expensive gypsum board, but can't be painted over, which usually isn't a problem for basement utility rooms.
Also, you can wire up your furnace to accept a battery backup (to run the fan)
I'm sure it would be possible to manufacture a much less jenky solution. Useful if you think the power grid in your area will fail more often than the furnace itself.
0.5 gram microsd delivered by 12,000 pound combustion vehicle and driver.
BTW: I find my furnace also makes a high pitched squeal. But knowing the startup sequence, its definitely coming off the natgas valve. Seems more pronounced on cold days.
0.5 gram microsd delivered by 12,000 pound combustion vehicle and driver.