I have this Bryant Furnace Model 398BAZ036060 (90i) plus
This furnace has had its fair share of problems but this one I fear is going to put me in the poor house.
Here is the problem
This furnace will only run in emergency heat mode and it runs well and has for months this way
In normal mode the Blower will give out a deep hum and the fan wheel just sort of sits there "shaking" but will not rotate.
If I give it a slight nudge it will ramp up to speed normally (the bushings/bearings are in good condition)
I am aware that this is either a DC or Variable speed electronically driven motor and has a huge control box mounted to the motor end of the blower housing.

When this problem started I had just had the secondary heat exchanger replaced and the tech was powering up this furnace for the first time. I originally thought some object had got into the fan wheel and throwing it out of balance.

Regardless, this problem did not manifest again until a few weeks later when it became a constant effort for this blower to start when called (except in Emergency Mode)
I had pulled the blower assembly out and took a good look inside the controller box.
SEE PHOTO ON THE RIGHT
There is a circuit board and two fuses inside and your usual big capacitors and some heavily heat sinked devices. The fuses were fine, and a careful visual inspection did not reveal any damage. The Caps looked OK and "ohmed out" OK I didn't have a capacitance meter
One uncomfortable finding in all of this is and I question if it was due to inept work or sabotage by the tech. One of the female push on terminals from the Motor harness to the control board was barely if at all pushed on, it was just sort of touching the male counterpart. BOTTOM WHITE WIRE IN PHOTO (LEFT)
I think I need a new motor control and or motor and controller/fan assembly, either that just run it in emergency heat mode? :eek:

Almost all qualified service persons will use the factory service meter,harness and tools to diagnosis a problem with the variable speed drives. All other type tests are useless. You are talking about two separate very expensive parts so I would be having them tested properly before just replacing them. The circuit board also has control over that variable speed motor.

Sorry but that is all the information I have unless you have the proper tools. Without them the trouble shooting guide is of no use at all.

The emergency mode is only intended for short-term use on this unit, typically to overcome (short-term) a problem with the secondary heat exchanger. The module in the photo looks as if something has burned and left a brownish residue on the inside of the casing. Unfortunately, the early version you have will require a new motor as well, since that type is completely obsolete. Was the secondary h/x replaced in-warranty?

Thank you both for your reply
Time to buy a Trane
This Bryant is a good unit when it runs, I like how quiet it WAS
After all I have been through I will not ask for another service call, it will be featured in an upcoming series of you tube videos showing failed secondary heat exchanger components, inducer motor rotor magnets unglued, rust streaks over the main controller board.
I was informed by Carrier that a warranty replacement paid the servicing dealer four hours labor and the exchanger was free, fair enough...

I was sold during my warranty replacement of the secondary heat exchanger a $200.00 flame sensor that was working just fine 1 day before, Uh Ohhhhh Kayyy :confused:
Then I find:
1) High tension lead insulation cut
2) This White wire not installed correctly (Can you say Transient voltage spikes?)
3) No clamp on the upper condensate tube resulting in a leak
4) replacement self adhesive inducer housing gasket unused in the garbage and housing leaking because of it! :mad:

I am quite sure the failure of this blower controller was due to that white wire being loose (it is the AC input to the Fan Control) Or it was the acidic condensate leaking all over the main board
Would you be angry?

May dishonest service techs rot in a stinking service call for eternity, and all the good ones be blessed in never having a bad one ;)

Tech quote upon leaving:
"You know these old units fail with more and more parts needing replacement"

So much for a service economy... I was "serviced" all right
Sorry in advance for my rant

"to acquire wisdom, one must observe" well spoken my friend
:rolleyes:

"Money is one tool... People need bigger toolboxes"

I need a new furnace despite the new heat exchanger

How many have spent thousands to repair a Carrier Corporation, Bryant, Night & Day, and Payne High efficiency series furnace? So sad

I hate to say this but all the other manufactures have there share of problems also. I really hate it when a tech does not do a job correctly. This kind of a screw-up would have caused a firing in my old shop. I would not let sloppy people work for me and ruin my business reputation.

How many years old is your furnace? Might be able to slip in a regular 3 speed motor cheaper. I believe you have the smarts to do that.

If I were you I would also take this up with Carrier since there authorized service company did the work. If someone tried to pull that on me there would be repercussions.

It pains me to hear a story like yours; one bad company or tech gives us all a bad name. I agree with hvac1000 that you should take this up with Carrier corporation. What have you got to lose, besides some of your time?

I hate to say this but all the other manufactures have there share of problems also. I really hate it when a tech does not do a job correctly. This kind of a screw-up would have caused a firing in my old shop. I would not let sloppy people work for me and ruin my business reputation.

How many years old is your furnace? Might be able to slip in a regular 3 speed motor cheaper. I believe you have the smarts to do that.

If I were you I would also take this up with Carrier since there authorized service company did the work. If someone tried to pull that on me there would be repercussions.


It is a 07/ 1989 Model
What would be the difference between running in emergency mode if I had a 3 speed motor, and what would control that?
Surely there must be junked models of this furnace with salvaged and serviceable parts?
Or is that a "no no" in this industry?
Have you ever seen a failed PRIMARY heat exchanger in this series?
Not that Carrier ever contacted me to warn of a problem in the past with this furnace, I doubt they would do much going forward.
I know far more than most consumers and no doubt more than some service techs about this model. I will limp through the rest of this heating season and replace it come spring.
The class action lawsuit was blocked in my home state regarding this furnace