On 18 Sep 2006 06:53:38 -0700, "drewink" wrote:


Robert Gammon wrote:
drewink wrote:
I have a builder grade Comfort Maker single stage furnace that has a
bad heat exchanger. It is 5 1/2 years old and still under warranty.
The part is free, but install is $1500. They gave me the option of
replacing, or installing a new Trane 2 stage furnace for $3500. They
said that I could save $500-$700 per year with the 2 stage. I have dual
zone heating with the second Comfort Maker furnace in the attic. It is
working fine. Is it worth having the better furnace installed, or is
the guy blowing smoke? I have used this HVAC company for many years,
but I know nothing about HVAC except change filters and service twice
per year. The total heating area is approximately 3300 square feet. Any
help would be appreciated.

Drewink


Where do you live?? How much do you use this furnace?? (same question
posed a different way)

What is the efficiency rating of the furnace with a bad heat exchanger
and what is the efficiency of the new unit?

Until we know the answers to these questions, we can't possibly answer
your question.

You MUST do something as a bad heat exchanger is DEADLY.

Efficiency ratings of the old furnace and the new one and how much you
use the furnace will tell you how long the payback is on a new furnace.

5.5 years is an unusually short lifetime on a heat exchanger. Did he
say what was the likely cause???? Suspicious minds want to suggest that
either the the builder grade furnace is really low grade or defective
from the factory (possible, but doubtful), or the HVAC guy is not
telling the whole story. Some HVAC service people have been know to
stick screwdrivers thru the heat exchanger just to promote a sale. Well
actually, a good heat exchanger will stand up to a moderate blow from a
flat head screwdriver. A heat exchanger that is dangerously weak with
rust will fail in these conditions.

Did he SHOW you the hole, or did you see it first and call him????

I live in Maryland so the usage for heat is up to 8 months per year. He
did not show me the hole. He said it was rusted. I did have a leak from
a clogged drain last year. He found it during the fall inspection. The
efficiancy on the old unit is 80% (Comfort Maker FBF Series). The
proposed Trane is also an 80% but 2 stage vs. 1. Summers are hot so AC
runs constantly for 3 months.

5 1/2 years sounds like "way too little" for Maryland.

$1500 labor-only sounds like "way too much" from the folks that
installed the old unit.

I'd either learn to check the HE myself or get a recommend
from a neighbor/friend and have a different contractor take
a peek at it.

To check yourself, you'd need a hinged mirror kinda like
the dentist uses, and screwdriver/wrenches to remove
some furnace components fastened with sheet-metal screws.
Folks in this forum can help with instructions.

Regards,
Puddin'

Pease pudding hot,
Pease pudding cold,
Pease pudding in the pot
Nine days old.