Carrier/Bryant HX problems

rich pickering

This comes up all the time at HVAC-Talk. There are at least 4 Carrier reps and a number of other brand reps.
Here is the general consensus.


If the hx is cracking on most furnaces, the hx is stressed from overheating or lack of airflow. No sense repairing/replacing until you find out why.

Goodman had a problem at the factory with the machine that made the crimp rings, but that was a long time ago.

The old 90% carriers had a problem with the lining in the secondarys delaminating.

Sooting is usually a gas/air, venting problem.

FWIW, I don't recall any bulletins regarding problems with sooting.

S Ebels

Failed HX's

We don't sell Carrier or Bryant but do service a lot of them in our area. We've seen an unusual amount of them with failed and or sooted up heat exchangers. Most of the time the secondaries are packed with soot but we have also seen primary sections that are cracked. None of the furnaces that we have replaced (with different brands) showed any sign of overfiring. Several of them even had the low gas pressure limit switch installed that C&B started to send out with their LP kits several years ago.

Not being a dealer for Carrier, I don't get any service bulletins or the like. Does anyone know if they have acknowledged a problem with these units? If so, is there anything that can be done to an existing installation to help prevent it from happening.

I went on a service call (no heat) at about 10:30 last night and found this particular 40K input Bryant to be making over 5000 ppm CO in the flue gas. Probably more because when I yanked the Testo out of the exhaust it was still climbing. Those kind of numbers scare the living **** out of me!

Joe Grosso

Carrier

steve, I don't work on gas, but know those who do. There is definately problems with the heat exchangers on units newer than 10 years old.Even ones installed perfectly as far as temp rise, etc. etc.
I hear Guys talk about a PAV (?)model that is pretty bad.
They like using the expression "Carrier to the curb"

S Ebels

Hmmmm

Interesting to hear that. I guess I was wondering because we've run into way too many for it to be just freaky breakdown type stuff. It doesn't seem to be confined to one model. Seen it on MCA, MXA and even MVP's (variable speed two stage)

Are there any Carrier dealers out there that have an answer from the factory?

John Mills_5

PAV etc

We have tons of them installed in our area, mostly RNC hideous duct systems. Very rare to find a bad heat exchanger. These are all natural gas. The old 60% clamshell types, now they liked to rust quickly but the serpentine made for the 80s & 90s have been good. On the older 90s, wasn't unusual to find secondaries plugged with corrosion & caulk. Haven't found any issues with the current generation, MXA etc.

Gary Reecher

There was a problem with Carrier not leak testing the replacement secondary heat exchangers on the first generation 90+ furnaces. Found quite a few new replacements that would leak water out the rivet joints.

Gary Reecher

There was a problem with Carrier not leak testing the replacement secondary heat exchangers on the first generation 90+ furnaces. Found quite a few new replacements that would leak water out the rivet joints.