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halmann
Help with hot water circulation motor

We have hot water baseboard heat. Over the past few months, a vibration developed and transfers noise through the pipes and therefore through the whole house. It only happens when the water is circulating and seems to be coming from the electric motor. I feel it when placing my hand directly on it.

My question is......do electric motors somehow develop an imbalance that causes a vibration and is replacing the motor the appropriate fix? Or, could it be something else?

We otherwise have no problems with the heat output, it's just an annoying noise and may signify a developing problem.

I found a replacement motor on the internet and the replacement procedure doesn't look complicated. Should I also replace the coupling and/or anything else?

Thanks

johnjh2o
Re: Help with hot water circulation motor

Sounds like you have a circulator with a spring coupling. There is a good chance the spring coupling is the cause of your problem. Replacing the coupling may be all that's needed.

jim hankinson
Re: Help with hot water circulation motor

If this is a 3 piece circ, (bearing assembly, coupling and motor) it's also possible that the motor mounts are getting spongy and the motor and bearing assembly shafts no longer line up. Either replace the motor mounts or replace the standard coupling with a spiral coupling.

von_steuben
Re: Help with hot water circulation motor
halmann wrote:

We have hot water baseboard heat. Over the past few months, a vibration developed and transfers noise through the pipes and therefore through the whole house.
My question is......do electric motors somehow develop an imbalance that causes a vibration and is replacing the motor the appropriate fix? Or, could it be something else
Thanks

If you have an older heating system it probably has one of the larger circulator motors (as hankinson describes) that has little spring-loaded oil filler caps on the top front or back of the motor that you can open to squirt in an ounce or so of motor oil (regular 30W automotive motor oil is ok)---you have to keep the bearings manually lubricated---have you been oiling the motor at least once a heating season??---it sounds like the bearings have not been oiled & are now seizing up----try oiling the bearings to see if it clears up the noise---place a small plastic bucket on the floor directly under the pump to catch any excess oil----if the oil doesn't work, try slightly lifting the back end of the motor while it is running---if that eases the noise follow hankinson's suggestions---bearings or motor mounts can be replaced without replacing the entire motor---call your local heating service technician, or consult the Yellow Pages under "Heating Contractors".

halmann
Re: Help with hot water circulation motor

OP here,

Yes, it's an old furnace - circa 1960's. It's been serviced well through the years and I do oil the motor - in fact, probably over oil it - have rags on the floor to catch the drips.

The furnace was serviced professionally this past fall - the technician didn't notice anything amiss but did remark on my oiling prowess.

I tried lifting the rear of the motor (von_stuben suggestion), the noise changed but the vibration improved only slightly.

I think I will order the parts each of you suggested - coupling, mounts, even the motor. New motors are quite expensive but I located a used one. I plan to put up with the vibration hopefully through the heating season. At least, since I'm doing it myself, I won't freeze if I run into a complication.

Thanks for the helpful comments

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