Gas and Oil Home Heating Furnaces - Noise in heating ducts

Doityourself.com community forum was created to provide answers to all questions related to home improvement and home repair. Doityourself community can help you find information about how-to topics on small fixes to large remodeling projects. With comprehensive how-to content and expertly moderated community forums DoItYourself.com makes it easy to tackle even the most complex home improvement projects.



PDA

View Full Version : Noise in heating ducts

04-19-01, 10:29 AM
Does anyone know what I can do to eliminate noise in ducts due to thermal expansion?
I've located the spot it's coming from, where the chimney pipe passes through the roof.

fjrachel
04-19-01, 04:35 PM
I'm assuming you have a metal B vent type exhaust flue. Chimney's are made of brick.
Is the noise coming from the flue or the duct?
04-25-01, 09:25 AM
The noise actually seems to come from the cone-shaped "flange" that provides a seal around the flue where it passes through the roof.
It sounds like water dripping onto this, but it happens whenever the heat comes on. My first thought was that water was dripping onto it outside from snow melting, but there's been no snow for a while and the noise persists.

fjrachel
04-25-01, 07:06 PM
I don't know the correct name, but I call it a witch's cap. You may try getting up on the roof and checking your flue cap on the top of the flue, it may have gotten damaged and is not letting the flue gases escape quickly enough. Or check under the rain collar and remove any drill screws from the top of the witch's cap to the flue(make sure flue is supported below) and fill any gaps with a rubberized fire rated silicon.