Hope this isn't too dumb of a question. We have a forced air system and
whenever it's on and hot air is blowing, a fan inside a container that's
mounted on the side of a duct begins to spin. The problem is it's making a
very loud kind of rattling noise as if something is loose. It's never
sounded like that in the 7 years we've lived here until now. It stops
spinning when the forced air stops, so it's not a problem of getting to shut
on or off, just that I'm not sure why it's so loud now.

I feel silly as I'm not even sure exactly what this unit's function is
(assuming it's for cooling?), but it seems to only go on when the thermostat
is set a little high. It's also connected to a switch (set to on) that's
mounted on the side of the furnace. This is a different switch from the main
power for the furnace system. I don't know much about these systems, but I'm
assuming this is different from the 'blower' in the furnace chamber.

Can someone please explain this to me? What could be wrong with the unit?

Thanks

keni wrote:
Hope this isn't too dumb of a question. We have a forced air system
and whenever it's on and hot air is blowing, a fan inside a container
that's mounted on the side of a duct begins to spin. The problem is
it's making a very loud kind of rattling noise as if something is
loose. It's never sounded like that in the 7 years we've lived here
until now. It stops spinning when the forced air stops, so it's not a
problem of getting to shut on or off, just that I'm not sure why it's
so loud now.
I feel silly as I'm not even sure exactly what this unit's function is
(assuming it's for cooling?), but it seems to only go on when the
thermostat is set a little high. It's also connected to a switch (set
to on) that's mounted on the side of the furnace. This is a different
switch from the main power for the furnace system. I don't know much
about these systems, but I'm assuming this is different from the
'blower' in the furnace chamber.
Can someone please explain this to me? What could be wrong with the
unit?
Thanks

I can think of three things it may be.

* Most current furnaces use a power vent to exhaust the combustion
gases outside. If it is getting louder, it may need service soon. Have
this one checked at once as it may leave you without heat if it goes out.

* It may be part of a humidifier. It may need service especially if it
has not been serviced during the last 7 years.

* Some one may have added a booster fan to help get more air to a cold
room. If it is getting louder then it needs to be serviced or removed.

--
Joseph Meehan

26 + 6 = 1 It's Irish Math

On Thu, 13 Jan 2005 09:52:56 GMT, "keni"
wrote:

Hope this isn't too dumb of a question. We have a forced air system and
whenever it's on and hot air is blowing, a fan inside a container that's
mounted on the side of a duct begins to spin. The problem is it's making a
very loud kind of rattling noise as if something is loose. It's never
sounded like that in the 7 years we've lived here until now. It stops
spinning when the forced air stops, so it's not a problem of getting to shut
on or off, just that I'm not sure why it's so loud now.

I feel silly as I'm not even sure exactly what this unit's function is
(assuming it's for cooling?), but it seems to only go on when the thermostat
is set a little high. It's also connected to a switch (set to on) that's
mounted on the side of the furnace. This is a different switch from the main
power for the furnace system. I don't know much about these systems, but I'm
assuming this is different from the 'blower' in the furnace chamber.

Can someone please explain this to me? What could be wrong with the unit?

Thanks

Seven years and you've never had a professional look at your system?
Terrible, just terrible.
Do you have your car serviced every 7 years too?
Bubba

keni wrote:
Hope this isn't too dumb of a question. We have a forced air system
and
whenever it's on and hot air is blowing, a fan inside a container
that's
mounted on the side of a duct begins to spin. The problem is it's
making a
very loud kind of rattling noise as if something is loose. It's never

sounded like that in the 7 years we've lived here until now. It stops

spinning when the forced air stops, so it's not a problem of getting
to shut
on or off, just that I'm not sure why it's so loud now.

I feel silly as I'm not even sure exactly what this unit's function
is
(assuming it's for cooling?), but it seems to only go on when the
thermostat
is set a little high. It's also connected to a switch (set to on)
that's
mounted on the side of the furnace. This is a different switch from
the main
power for the furnace system. I don't know much about these systems,
but I'm
assuming this is different from the 'blower' in the furnace chamber.

Can someone please explain this to me? What could be wrong with the
unit?

Thanks

It's sounds like it's the inducer fan, it's helps to blow the exhaust
out the vent into the chimney. Like any motor, over time the bearings
get worn and needs replacing. The inducer fan only comes on when the
t-stat calls for heat.

It's the humidifier. I can see it from here.
"Mikepier" wrote in message
oups.com...

keni wrote:
Hope this isn't too dumb of a question. We have a forced air system
and
whenever it's on and hot air is blowing, a fan inside a container
that's
mounted on the side of a duct begins to spin. The problem is it's
making a
very loud kind of rattling noise as if something is loose. It's never

sounded like that in the 7 years we've lived here until now. It stops

spinning when the forced air stops, so it's not a problem of getting
to shut
on or off, just that I'm not sure why it's so loud now.

I feel silly as I'm not even sure exactly what this unit's function
is
(assuming it's for cooling?), but it seems to only go on when the
thermostat
is set a little high. It's also connected to a switch (set to on)
that's
mounted on the side of the furnace. This is a different switch from
the main
power for the furnace system. I don't know much about these systems,
but I'm
assuming this is different from the 'blower' in the furnace chamber.

Can someone please explain this to me? What could be wrong with the
unit?

Thanks

It's sounds like it's the inducer fan, it's helps to blow the exhaust
out the vent into the chimney. Like any motor, over time the bearings
get worn and needs replacing. The inducer fan only comes on when the
t-stat calls for heat.

"Bubba" wrote in message
...
On Thu, 13 Jan 2005 09:52:56 GMT, "keni"
wrote:

Hope this isn't too dumb of a question. We have a forced air system and
whenever it's on and hot air is blowing, a fan inside a container that's
mounted on the side of a duct begins to spin. The problem is it's making a
very loud kind of rattling noise as if something is loose. It's never
sounded like that in the 7 years we've lived here until now. It stops
spinning when the forced air stops, so it's not a problem of getting to shut
on or off, just that I'm not sure why it's so loud now.

I feel silly as I'm not even sure exactly what this unit's function is
(assuming it's for cooling?), but it seems to only go on when the thermostat
is set a little high. It's also connected to a switch (set to on) that's
mounted on the side of the furnace. This is a different switch from the main
power for the furnace system. I don't know much about these systems, but I'm
assuming this is different from the 'blower' in the furnace chamber.

Can someone please explain this to me? What could be wrong with the unit?

Thanks

Seven years and you've never had a professional look at your system?
Terrible, just terrible.
Do you have your car serviced every 7 years too?
Bubba

This is Turtle.

As My Good Friend Jim Carry would say I have my furnace and car serviced every
20 years wiether it needs it or not.

TURTLE