DIYbanter - View Single Post - furnace blowing all the heat up the chimney

Tony Hwang

wrote:
I'm tired of people telling me that there's nothing wrong with my
furnace. There is something wrong with my furnace.

It's a 10-year-old Amana 45,000 BTU, 80% efficient unit in a 1300
square foot ranch style house. This is my 4th winter in this house,
and I'm sick of being limited to one habitable room all winter.

The air coming out of the vents is cool, around 70 degreees according
to my thermometer. The exhaust to the chimney is smokin' hot. The
plenum does not get perceptibly warm.

I change the filter regularly. The old filter comes out visibly just
as clean as the new filter I put in. There is plenty of airflow
through the unit, as I can feel the cold draft hit my feet from across
the room when the furnace kicks in.

The flames are steady and clean blue.

I have to close off all the bedrooms and heat only the living room and
kitchen during the coldest months, otherwise the furnace would run
24/7 and the temperature would never get above 62.

The pros say there's nothing wrong.
Hi,
To me the furnace is a bit undersized to begin with.
First thing first,
If blower motor has a speed tap, it should run slower than when in
cooling mode.(warm air is light vs. cold air) Does cooling mode work OK
in summer? Had a look at evaporator coil? Is it clean?