new circulator squeals when it shuts down

GatesMan

I replaced my 30 year old B&G Series 100 circulator more than a month ago. The whole unit - motor, bearing assembly, coupler, impeller. When running, it is quiet and smooth and seems to be working just fine. But every time it shuts down, it emits a brief squeal, just for a fraction of second. This can be heard throughout my 3 story house, as the noise is transmitted up by way of the heating pipes. It actually sounds louder away from the unit. When I'm in the basement right next to it, it's not very loud at all.

I tried to locate the source of the noise using a modified stethoscope. The impeller and bearing assembly sounded the same - relatively loud. It was much quieter at the motor.

During the time it's been doing this, there were times I thought it was getting better, or that it had even stopped. But it always comes back. It does not seem to be getting worse, however.

I've asked many people about this, including B&G, but no one seems to have run into this before. I'm hoping someone on this forum has.

Charlie from wmass

Did you oil it?

They are not oiled from the factory you need to once they are install.

GatesMan

I did lubricate it

Yes, thanks, I should have mentioned that. It came with a tube of oil and instructions about how much to put in the bearing assembly and at both ends of the motor.