thump sund in heating duct
 

there is a banging noise in heating duct shortly after furnace comes on it
only happens once. Is this due to the expansion of the sheet metal?

Either that, or Bruce Willis is filming another Die Hard movie.

t&k wrote:
there is a banging noise in heating duct shortly after furnace comes
on it only happens once. Is this due to the expansion of the sheet
metal?

When the fan goes on the pressure in the ducts change and some of them
may flex in or out. You may notice that larger panels are often creased to
provide a little more strength to prevent this problem. If you hunt down
the specific part that is flexing you may be able to shim or stiffen it to
eliminate the sound.

--
Joseph Meehan

26 + 6 = 1 It's Irish Math

an alien chasing sigorney?

"t&k" wrote in message
...
there is a banging noise in heating duct shortly after furnace comes on it
only happens once. Is this due to the expansion of the sheet metal?

there is a banging noise in heating duct shortly after furnace comes on it
only happens once. Is this due to the expansion of the sheet metal?


Yes, it's called the "oil can" effect. Just a nuisance, nothing more...

Ed

Sounds like a demon. Better call TAPS.
Joe


t&k wrote:
there is a banging noise in heating duct shortly after furnace comes on it
only happens once. Is this due to the expansion of the sheet metal?

I watched that show last night.... finally was forced to turn the
channel when I saw em flashing that $10 temp probe around and being
astounded when it went from 60 to 50 to 45 to 60..... Well, um.... DUH.


The every 15 minute adverts for roto rooter don't do much for me either.

On 30 Dec 2004 04:33:18 GMT, (AUSTIN1880) wrote:

there is a banging noise in heating duct shortly after furnace comes on it
only happens once. Is this due to the expansion of the sheet metal?


Yes, it's called the "oil can" effect. Just a nuisance, nothing more...

Ed

Actually, its called, "The ductwork probably isnt sized properly".
Most likely, the furnace is too big or the ductwork is too small.
Either way, it means a shorter life span for your heat exchanger and
associated temperature controls in your furnace like the high limit.
Then of course we can get into the air conditioning but thats a whole
nother story.
Bubba