Humming in My Cold Air Returns

Hello everyone I am new with coal and have a koker lite furnace that I recently just got hooked up and started. I have just plumbed in my cold air returns from upstairs and used 12x3.25 square duct than dropped in 8 inch to my stove, I am noticing a humming sound all throughout my house and is worse when blower comes on. Any ideas to why this is happening?

Tlman,

Could you hear the humming before hooking up your cold air ducts??

Tim

Could not hear it as I just got the stove running last week, but as soon as u pull my pipe away from blower I can't hear it

Do you have your cold air ducts connected to the blower?

Sounds like the ducts are vibrating from the blower if the ducts are not secured to blower and you can hear it resonating through ducts.

I have a K-lite but never heard any humming from my unit.

Tim

Just a suggestion here, maybe replace a section of that 8 inch cold air duct with some insulated flex duct. That should prevent vibration transfer to the house.

I use insulated flex duct on my heat runs and it's nearly dead silent.

Pipes are securely connected to the blower

I can still hear a humming even when the blower is not running

Can you add a rubber coupling?

https://www.amazon.com/Fernco-Flexible-Coupling-1056-88-Plas ... 2+coupling

140* max. I honestly don't know anything bout forced air, and if that is within spec?

Unplug it & see what happens.

I unplug stove and it goes away..

With the power off it stops, then what you may have been hearing is the "hum" of a step-down transformer, or a relay ? 60 cycles/sec is about the frequency of what we think of as humming.

If there is a piece of the electrical controls mounted on sheet metal that is causing that vibration in there, it may just need a vibration dampening pad under it, like one cut out of a roll of automotive exhaust gasket material. Easy way to check is open it up and push gently on the controls and see if the humming stops, or at least changes pitch.

And if it's not that,.... then it might be like the old punch line, "It's humming 'cause it doesn't know the words to the song !"

Paul

Cup your hand and put it over your ear...hear that noise?...now take that big empty plastic tote that your Christmas decorations were in and put that over your ear...nothin" right....your duct work went from 8 inch round to 12 X 3.25 so the sounds of your basement are resonating through the duct work. I would make the all the duct work the same size or bigger. The flexible duct that was previously mentioned should work also.

Could it be the capacitor on the blower?

michaelanthony wrote:Cup your hand and put it over your ear...hear that noise?...now take that big empty plastic tote that your Christmas decorations were in and put that over your ear...nothin" right....your duct work went from 8 inch round to 12 X 3.25 so the sounds of your basement are resonating through the duct work. I would make the all the duct work the same size or bigger. The flexible duct that was previously mentioned should work also.

Mike,
But, so does turning off the power to the unit. That right there shows that the hum it's not caused by anything to do with duct work - that's just a symptom, not the disease- it has to be something electrical that is always getting power when other electrical parts of the heating system are off, until all power is shut down.

Paul

Tlman012 wrote:Could it be the capacitor on the blower?

That should only have power to it when the blower comes on.

Paul