DIYbanter - View Single Post - bulges and "hot spots" inside 20 year old furnace...do I really need new one?

dpb

wrote:
I had my 20 year old Carrier forced air furnace tuned up today. The
technician snaked a camera up the inside of the furnace. He did NOT
find any cracks, but he found "bulging spots" which he also referred to
as "hot spots", inside the furnace. He claimed the heat exchanger had
these bulges and claimed that this is a sign that it is getting close to
developing cracks, and showed me the bulges.

But I wonder if what he showed me really was the heat exchanger....can a
camera can really be snaked up inside a heat exchanger?...or was what he
showed me something else. I always assumed that a heat exchanger is a
tremendously dense piece of metal and that you would not be able to
"view inside it with a camera" only "view it from below with a
camera". This same cavity could also be seen without a camera by
looking into the furnace with flashlight (he had removed one of the
panels above where the burners are) What he showed me was was a
vertical cavity which had a couple of bulges on the sides of the cavity
which were bulging toward the outside. Is that really the heat exchanger
he showed me? What does the heat exchanger on a 20 Yr. old Carrier
furnace look like and exactly where is it located?

There is also some rust present on the inside of the furnace.

The burners look like they produce a nice blue flame.

The technician is recommending a new furnace based on the age and based
on the bulges and rust. Do I really need to be seriously thinking about
getting a new furnace at this time because of the rust and bulges, or is
it possible this furnace could last several more years? I believe they
recommended a new furnace 3 years ago when I moved in although I don't
recall anyone showing me the bulges before, but I'm suspecting they
could have been present 3 years ago too.

BTW, the company I've been using prefers to install Goodman systems,
although they would also be willing to give me a price on another brand
that I have in mind which is Carrier. They say that they will warranty
both the parts and labor for 10 years on the Goodman, but the warranty
on the Carrier would depend on what their warranty is. Is a Goodman
likely to last as long as a Carrier?

It is possible. The key item is did he do a CO test? The risk in a
cracked condenser is flue gas in the warm air stream which is a serious
potentially fatal problem. While not as sensitive as a real instrument,
a CO monitor could spot a serious problem.

Goodman is one of the lower initial cost units but seems recently (last
couple of years from anecdotal evidence) to have upped their warranty
periods. What the actual failure rates are for their gas furnace units
I don't know but the last CR ratings for A/C units had them at the
complete bottom and separated from the rest of the pack by a significant
margin. I'd do a little investigative digging before jumping in,
particularly if there is an A/C unit involved as well as the furnace.

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