"JoeSpareBedroom" wrote in message
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wrote in message
oups.com...
Just noticed that when our furnace comes on, there is a distinct
"engine roar" sound. Upon investigation, if you put your ear up to the
wall where the vent line goes up to the roof (from the furnace), it is
definitely this wall that the new noise is coming from. Furnace and
home is 3 yrs old, nothing different this winter except we had a
central A/C put in over the summer. Just changed the filter and noise
is still there. What could causing this roaring sound?


Some sort of obstruction, maybe? Creature? Bird's nest? Is the vent capped
to prevent this sort of thing?
Ditto that. Air attempting to rush through a narrowed opening (venturi?)
makes noise. Think, air rushing in through a crack around a door - maybe
you're too young to remember the days before weather-tight homes.