Ducts are making a LOT of noise lately!

WildIrish · Fri Jan 23, 2009 2:51 am

I think I might have posted this question in the wrong forum, so I'll post a link to it unless/until a moderator can move it to the right place:

viewtopic.php?p=27284#27284

Is this problem related to the ducts not being fastened to the floor properly, or what? This isn't the normal noises, but a huge BOOM every so often that wakes everybody up.

(If somebody moves my post, can they please reply to this one, to let me know where it's been moved to? Thanks!)

tritontr · Fri Jan 23, 2009 8:15 am

Do you heat with gas, electric strips, or heat pump? Is your heat/ac unit a package unit(the whole system is located outside) or a split system where you have the air handler(furnace) located inside and a condenser outside?

Greg · Fri Jan 23, 2009 5:54 pm

Irish, is the noise when the furnace first starts up or after the fan kicks in to blow the air down the ducts?

If it is on startup, I would get the furnace checked. If it is a duct problem it could be something has come loose, but the BOOM concerns me. Greg

WildIrish · Mon Jan 26, 2009 3:37 am

tritontr wrote:Do you heat with gas, electric strips, or heat pump? Is your heat/ac unit a package unit(the whole system is located outside) or a split system where you have the air handler(furnace) located inside and a condenser outside?

It's a gas furnace (Coleman). The air conditioner is outside, the furnace is inside a door just off the kitchen.

Greg wrote:Irish, is the noise when the furnace first starts up or after the fan kicks in to blow the air down the ducts?

It's whenever the metal expands or contracts...when the heat has been running, when the heat has been off. I can mimic the exact same sound by removing the register, reaching into the duct, and pushing on the thin metal walls. Also, if we walk over a duct (not a register, but in the middle of the floor), it can generate a softer version of the same sound.

Greg wrote:If it is on startup, I would get the furnace checked. If it is a duct problem it could be something has come loose, but the BOOM concerns me. Greg

It's not an explosion-type boom, that's just the best word I could think of to describe it. It's just a really loud and startling sound, that seems to be the worst in the vent/duct right near my mother's chair. (Due to back problems, she sleeps in that chair....)

Even if we moved the chair, the sound is still so loud that it'd wake her up, anyway.

Greg · Mon Jan 26, 2009 5:47 pm

There is no reason that the furnace should make enough noise to wake a person up.

Do me a favor and post the question in the Coleman heating section and get Robert's thoughts. I would attempt to move it myself, but I have a feeling it would end up in never-never land. Greg

Robert · Mon Jan 26, 2009 10:46 pm

Hi,

I moved this to the Coleman HVAC forum. Please follow it there.

Thanks,
Robert

Robert · Mon Jan 26, 2009 11:02 pm

Hi,

IF the duct trunkline was not installed properly or has become damaged or loose, it can make some fairly good racket when it expands and pops back into position.

If it was a furnace problem, noise should be heard from furnace area, not the duct so much.

However, because I'm not there, if at all not sure, better to have an hvac tech listen to it in person.

Thanks,
Robert

Robert · Mon Jan 26, 2009 11:06 pm

Hi,

IF the duct trunkline was not installed properly or has become damaged or loose, it can make some fairly good racket when it expands and pops back into position.

If it was a furnace problem, noise should be heard from furnace area, not the duct so much.

However, because I'm not there, if at all not sure, better to have an hvac tech listen to it in person.

Thanks,
Robert

WildIrish · Tue Jan 27, 2009 6:29 am

^ Robert, I think you've hit the nail on the head, because it's something that's just started happening, so maybe it's come loose or something.

We're going to have a tech out here to check out the furnace anyway, so we'll just have him check out that duct, too.

Thanks for your help, everyone!

Robert · Tue Jan 27, 2009 12:43 pm

You're very welcome, happy to help. Remove all the registers and starting at one end, lay bright light in the duct pointing toward next register.

Go to next register and hold mirror down looking back at the light.

Keep going one by one to inspect duct trunkline.

IF you have a digital camera, take pics all along, send to your email or a folder, enlarge and really have a close up view of duct.

Thanks,
Robert