# Loud humming noise from electric forced air furnace



## MissBehavin (Dec 27, 2008)

I have a 4 yrs old Nordyne electric forced air furnace in my manufactured home. Just recently it started making this loud humming noise after it's been on for 5 or ten minutes. Fan is working great and the unit puts out lots of heat, I am worried about using it in case the humming noise is a sign of something major.


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## yuri (Nov 29, 2008)

I would get it checked properly. It should be checked once a year for loose wiring etc. It may be that one of the elements/holder is coming loose after it heats up and then vibrates. Annoying but not dangerous. Had that happen to a Armstrong unit. Get it checked to be safe.


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## Yoyizit (Jul 11, 2008)

MissBehavin said:


> loud humming noise after it's been on for 5 or ten minutes.


Loose motor mount?


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## MissBehavin (Dec 27, 2008)

Just had my neighbor over to check out this furnace, All wires are good and tight. Fan is nice and clean and elements are connected as should be. Fan is nice and quiet without heat on. Ran it for a good ten minutes and it shut off when it reached 20 degrees celcius. This unit is only 4 yrs old and is serviced before every winter. Wondering if the problem is the transformer. Everything still looks like new in there.


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## Yoyizit (Jul 11, 2008)

MissBehavin said:


> Wondering if the problem is the transformer.


I'd use a garden hose to isolate the noise source. You need someone on the distant end to signal you when the hose end is on top of the noise.

How loud?
http://en.wikipedia.org/wiki/Sone

I suppose as the xformer heats up it could hum louder if the material around the coil windings softens up.
To identify a 60 Hz hum put your ear to a wall xformer. Flourescents hum at twice that freq.


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## yuri (Nov 29, 2008)

The problem is heat related. The furnace expands when heated and something is "loosening". Could be in the ductwork. If it works properly I would not worry too much about it. Don't be poking around in there when the unit is "live" as the 240 volts can kill you. I hear BC is not so beautiful when all socked in with snow, especially Vancouver airport at Xmas. Just joking. Have relatives in Abbotsford. Come to Wpg for some "real" winter.


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## MissBehavin (Dec 27, 2008)

Thanks for the help guys, Furnace appears to be working ok this morning no humming noises. As for winter in the Peg, No thank you I will stay here on the Southern Gulf Islands.


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## yuri (Nov 29, 2008)

Its a dry cold with mostly blue skies. Went on a kayak trip to see the Orcas years ago in the Johnstone Strait. Nice area, and Tofino is beautiful.


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## MissBehavin (Dec 27, 2008)

*Transformer was noisy*

Well guys it appears it was the transformer making the noise. Sprayed it with Beauti Tone clear lacquer from Home Hardware and now all is nice and quiet. Thank you very much for your advice and a Very Happy New Year to all.


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## Yoyizit (Jul 11, 2008)

This kind of behavior will never save the world's economy!
:laughing:


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