Can an occasionally squealing draft inducer motor be repaired instead of replaced?

Question

My 13-year-old Bryant furnace has occasionally made a squealing sound during the past two winters, with the problem gradually getting worse.

I had a repairman look at it, and he said it is the draft inducer motor going bad. He said the motor assembly needs to be replaced, since it can't be repaired, and quoted me $850 for parts and labor. He said the labor would be $200, and he would do some maintenance and replace another part as well.

I read that Bryant inducer motors can be repaired rather than replaced. Is that true? Do these draft inducer motor assemblies really cost several hundred dollars?

The furnace model number is 311JAV024070ADJA. Here are a picture showing the label and (I think) the draft inducer. He said the motor is a standard one easily available, and I found the part number: HC21ZE121.

Answer 1

Intermittent squealing is common for "permanently lubricated" sleeve bearings that are reaching the end of life (whoops, not so permanent after all.)

Such bearings are typically a sintered (porous) bronze impregnated with oil. As they age, some oil is lost, and since no way to replenish oil is provided, the surface can dry out and squeal. As the bearing heats up the remaining oil eventually makes its way to the surface and the squealing stops again.

Short of disassembling the motor, pressing out the old bearings, pressing in new bearings, reaming them to size, and reassembling they are not particularly serviceable. Often the motor they are in is assembled in a way that makes disassembly without destruction impractical.

Answer 2

The project is finished. The answer to my question is that yes, you can repair an inducer motor (at least my motor) instead of replace it. But due to my own carelessness I didn't. Here is what I did right, and what I did wrong.

Following advice here I decided to replace the inducer motor myself, so I called the repairman to cancel and he asked me to pay his normal $150 service call fee for the initial diagnosis, so I will. Better than paying $850 for the replacement.

I bought a new inducer motor from Amazon using Prime for $88 and it came the next day. It took me a while to find a gasket for a reasonable price, but I finally found one for $12 (part and shipping) that came in two days.

I had already taken out the old motor and thought about taking it apart to see what bearings it had but for some reason did not. More on that later.

Due to various stupid mistakes it took me about 30 minutes to remove the motor, and then three days later, about 30 minutes to replace it. It was a little hard to keep the gasket in place, and it may have slipped out of place. Apart from that the replacement went well.

The new motor is completely silent. I turned the furnace on for a test and almost turned it off again, thinking that the motor wasn't running. Then the flame came on and I looked more closely and saw that the inducer motor was running, but silently.

Then I remembered to take apart the old motor to see how the bearings had failed, and I'm sorry I did. The motor housing came apart easy enough and I found that the motor had ball bearings, not sleeve bearings. The size is the common 608 and you can buy 10 of them from Amazon for $5 (free delivery).

So unless I'm missing something, I could have replaced the bearings for $5 and had a perfectly serviceable motor if only I had looked at the old motor before installing the new one (which I could have returned for free).

Motors don't (normally) wear out, just bearings. The bearing on the furnace side is the one that is noisy. I pulled off the rubber seal and it has no grease at all inside. I greased it, but it still makes noise (a ticking, slightly grinding sound, not a squeal). It's shot, and I'm sure it degraded because of the heat. The outer side bearing looks nice and greasy and sounds perfectly fine.

I ordered the bearings and they arrive tomorrow. I'll have to figure out how to pull the faulty bearing and press the new one back on. I had the tools for that before, but I can't find them now.

I could kick myself. Not just for the wasted money, but for replacing a motor that could easily be repaired with a 50-cent bearing. I'll repair the old motor, but I'm pretty sure I'll never use it again. Too bad the repairman lied about these motors being unrepairable.

Live and learn.