| Either you are incredibly fortunate, or we just happened to get a lemon.
I had one installed in 94. The first failure was the tuning valve (seal leaked). I noticed the water dripping onto the floor of the burner compartment and dribbling down onto the blower. At that time the unit was covered by a maintenance plan with a spinoff of the gas supplier. They had been quite helpful with the previous furnace, but they didn't seem to want to deal with this one. The tech first tried to claim that dripping water is normal for high-efficiency furnaces. Then he said he would replace that part. A few days later he called me to ask if I knew a contact number for Bryant(!). I gave him the 800 number, but I never heard from him again. Needless to say we didn't renew the maintenance plan. Fortunately I was able to order a new tuning valve (it's really just an adjustable cap) online. I still have the old one and I may try to rebuild the seal at some point.
The next failure was the internal drain tubes. They rotted out and started leaking more water onto the floor of the burner compartment. I couldn't find any specific replacement part for them so I used some transparent high-temp tubing similar to what I've seen in other brands of condensing furnaces. The original tubes were a black plastic/rubber that was more flexible but seemed to be attacked by the condensate and reduced to goo.
The next problem was a failed hot-surface ignition module. This was replaced by a service technician; however, I was a little curious about why it had failed so I watched the furnace carefully for a few days. This brings me to:
The next problem was in the control module. I observed that the furnace was cycling constantly when the thermostat called for heat. The burner would fire ok, but it would shut off even before the fan-on delay time. Then the fan would come on and run until the fan-off delay. Then (if the thermostat was still calling for heat) the burner would fire again and the sequence would repeat. Obviously this put a lot of stress on the hot surface module. The control module was not indicating any error codes and I eliminated the obvious causes (pressure switch, high-limit, flame sensor). To make a long story short, the problem was some failed solder joints on the control module's PC board. The load resistors for the thermostat loop are mounted a little off the board and soldered to grommets, but apparently not isolated well enough. The constant temperature cycling had broken the bond and allowed the connection to open when the resistors became warm during a call for heat. I soldered the joints a bit more completely and they have been ok for a few years. Note that Bryant eventually admitted to this problem and supposedly had some sort of free exchange program, but it was unclear to me (and to my service technician) how one might take advantage of the program.
The next problem was the blower motor. It started making horrible noises and caused the whole furnace to vibrate. The technician had a lot of trouble replacing the motor because the shaft had corroded to the fan cage assembly. (He used up all of my Dremel cutoff disks removing enough of the shaft to accommodate his clamp-on pulling tool. :) I suspect that the difficulty and the failure itself were caused at least in part by the previous leaks.
Lately the inducer motor has been making a terrible noise and vibration on startup. Once (if) it gets going it seems to be ok for a while. I suspect it will have to be replaced soon, though...
Dan Lanciani ddl@danlan*com