Loud buzzing sound from furnace

Dec 14th, 2015 9:00 pm

#1

arctics [OP]: Member; Nov 4, 2007; 427 posts; 35 upvotes

Dec 14th, 2015 9:00 pm

I've got an odd buzzing sound coming from our furnace. The sound is constant, not just when the fan is on, it only goes away if I flip the power switch.

The furnace is a 3 year old Keep Rite.

Anyone have any idea what might be causing this?

Share:

Dec 14th, 2015 9:50 pm

#2

socioguru: Member; Dec 1, 2010; 281 posts; 195 upvotes; Windsor

Dec 14th, 2015 9:50 pm

Ensure the cover(s) isn't loose. Could be draft inducer motor or fan.
Best call a HVAC to inspect; you wouldn't want to cause further damage.

+1

Dec 15th, 2015 9:47 am

#3

arctics [OP]: Member; Nov 4, 2007; 427 posts; 35 upvotes

Dec 15th, 2015 9:47 am

I'll check that, but doesn't sound like a vibration noise. Best way to describe it is to call it electrical noise.

I called my AC installer and they suggested it may be a transformer causing this.

Dec 15th, 2015 10:03 am

#4

schade: Deal Addict; Dec 17, 2007; 2619 posts; 1594 upvotes; Alliston, ON

Dec 15th, 2015 10:03 am

It could be the 24v transformer or one of the internal power supplies

+1

Dec 16th, 2015 1:04 pm

#5

JamesA1: Deal Fanatic; Mar 20, 2009; 8862 posts; 2687 upvotes; Vancouver

Dec 16th, 2015 1:04 pm

^ This. Many furnaces use 24vdc power for their controls, and they have a 110vac/24vdc transformer mounted next to the furnace to provide power. Like any transformer it can buzz at the 60Hz powerline frequency if anything is loose.

Dec 16th, 2015 4:15 pm

#6

arctics [OP]: Member; Nov 4, 2007; 427 posts; 35 upvotes

Dec 16th, 2015 4:15 pm

Ok so sounds like this may just be something loose rather than a bad transformer? Also, could this be caused by a power fluctuation in the house?

Dec 16th, 2015 5:01 pm

#7

JamesA1: Deal Fanatic; Mar 20, 2009; 8862 posts; 2687 upvotes; Vancouver

Dec 16th, 2015 5:01 pm

Nah, transformer buzz is common. It's the strong magnetic field oscillating back and forth at 60Hz. If anything is loose, including internal wire coils, it'll make noise. It makes more noise whenever it draws more current, because the magnetic field strength increases with the current.

Dec 16th, 2015 5:50 pm

#8

pootza: Deal Addict; Dec 19, 2009; 4713 posts; 2639 upvotes

Dec 16th, 2015 5:50 pm

JamesA1 wrote: ↑^ This. Many furnaces use 24vdc power for their controls, and they have a 110vac/24vdc transformer mounted next to the furnace to provide power. Like any transformer it can buzz at the 60Hz powerline frequency if anything is loose.

The transformer reduces it down to 24 volts AC ... not 24 volts DC

Dec 16th, 2015 9:10 pm

#9

arctics [OP]: Member; Nov 4, 2007; 427 posts; 35 upvotes

Dec 16th, 2015 9:10 pm

Ok is the transformer something I can replace on my own or should I get an hvac guy in?

Dec 17th, 2015 12:28 am

#10

pootza: Deal Addict; Dec 19, 2009; 4713 posts; 2639 upvotes

Dec 17th, 2015 12:28 am

Transformers are usually fairly easy to replace if you have a little sense with electricity. It may not even be necessary to change it as the buzzing doesn't mean it's actually failing as most normally buzz. Might not even be the transformer as it could be one of the relays instead.
Could possible use an insulated screwdriver and place it against the casing of the transformer or relay to see it the buzzing stops or if you feel a good vibration while it's operating to isolate which part it may be but lots of them buzz naturally.

Dec 17th, 2015 12:06 pm

#11

arctics [OP]: Member; Nov 4, 2007; 427 posts; 35 upvotes

Dec 17th, 2015 12:06 pm

The buzz is fairly loud and can be heard throughout the house from the vents.

My AC installer is quoting $160 plus parts if not covered by warranty. $80 to process the warranty plus $80 to replace the parts.

Is this reasonable, or should I look elsewhere?

Dec 17th, 2015 12:08 pm

#12

MacGyver: Deal Addict; Mar 8, 2002; 4232 posts; 876 upvotes; Ottawa

Dec 17th, 2015 12:08 pm

Are you sure the buzz isn't coming from the gas valve solenoid?

Dec 17th, 2015 1:12 pm

#13

arctics [OP]: Member; Nov 4, 2007; 427 posts; 35 upvotes

Dec 17th, 2015 1:12 pm

Ok, I was able to open up the furnace and pull out the transformer. The buzz is definitely coming from it. Problem is I can't find the exact same model transformer. Can it be substituted with something else?

By the looks of it, they range in price from $20 - $50. So why would I spend $80 to go through warranty if I can just substitute with something else?

Dec 17th, 2015 5:22 pm

#14

pootza: Deal Addict; Dec 19, 2009; 4713 posts; 2639 upvotes

Dec 17th, 2015 5:22 pm

arctics wrote: ↑Ok, I was able to open up the furnace and pull out the transformer. The buzz is definitely coming from it. Problem is I can't find the exact same model transformer. Can it be substituted with something else?

By the looks of it, they range in price from $20 - $50. So why would I spend $80 to go through warranty if I can just substitute with something else?

Yes other makes can be substituted, depends on the VA of the transformer. Give us the make and model number (a pic is usually nice) and someone will help you with a substitute.

Dec 17th, 2015 8:18 pm

#15

amace: Deal Addict; Aug 4, 2010; 2371 posts; 395 upvotes; Thunder Bay

Dec 17th, 2015 8:18 pm

arctics wrote: ↑Ok, I was able to open up the furnace and pull out the transformer. The buzz is definitely coming from it. Problem is I can't find the exact same model transformer. Can it be substituted with something else?

By the looks of it, they range in price from $20 - $50. So why would I spend $80 to go through warranty if I can just substitute with something else?

Peace of mind that it's working right? For $30 extra, why not have a trained pro ensure that a) that actually is a problem, and b) ensure the proper replacement part is in place. If you install it wrong, or put in a wrong part, you've potentially caused hundreds in other repairs.

Dec 17th, 2015 9:28 pm

#16

arctics [OP]: Member; Nov 4, 2007; 427 posts; 35 upvotes

Dec 17th, 2015 9:28 pm

[IMG]http://i188.photobucket.com/albums/z134 ... 0256_1.jpg[/IMG]

It would be $160 vs $50. But I get your point, doing it myself, I risk causing more damage. But by the looks of it, it seems like a very straight forward replacement. 4 color coded wires to plug in.

Dec 17th, 2015 9:44 pm

#17

schade: Deal Addict; Dec 17, 2007; 2619 posts; 1594 upvotes; Alliston, ON

Dec 17th, 2015 9:44 pm

all you need is a 24VAC 40VA transformer. Its a simple swap, just make sure you shut the power to your furnace off

24vac Transformer

+1

Dec 17th, 2015 9:54 pm

#18

Frankie3s: Deal Fanatic; Jul 4, 2004; 8990 posts; 1946 upvotes

Dec 17th, 2015 9:54 pm

Time to go to Amre supply, http://www.amresupply.com/

Help an animal charity or sanctuary out today. Become a volunteer, advocate, foster a pet, or donate. They need you as much as you need them!

Dec 18th, 2015 12:18 am

#19

fastmiele: Deal Addict; Mar 23, 2006; 1110 posts; 416 upvotes

Dec 18th, 2015 12:18 am

I am a bit confused, $80 to process warranty ?

My personal opinion is call for a maintenance cleaning/tune up and get them to include the transformer replacement at a reduced cost.
Hopefully you can watch what they do and learn some techniques which you can comfortably do on your own in the future.

Dec 18th, 2015 2:02 pm

#20

arctics [OP]: Member; Nov 4, 2007; 427 posts; 35 upvotes

Dec 18th, 2015 2:02 pm

$80 processing fee he said was to cover the time to call in the warranty claim, plus pick up the parts and send back the old parts.

I like that idea, arrange it as part of a maintenance cleaning. My thought is just that the part seems so simple to replace, so why not take care of it on my own.