Third coupler failure

Stonacious

Hey guys, I asked a circulation pump question here last year and got great answers back, as bad as I hate it I'd like to ask another. Is there something particular to the bright red circulation pump couplers going bad? Is there something that causes it or can a pump be bad? I woke up yesterday to a loud growling noise coming up from the mechanical room and I recognized it because every year for the last three years the couple on the circ pump has failed. And it's always at the 13-14 month after replacement. My guy told me today that they'd replace the coupler but might want to change pumps in the off-season, perhaps a bent shaft or a lob, some kind of imperfection? Have you ever encountered repetitive coupler failures? If so what's the fix? I didn't do anything to it, the whole furnace was just tuned up for the season Nov 24th. What's your experience with these?

Thanks all

Intplm.

It could be a misalignment of the shafts.

Is this a Bell and Gossett circulator?

They make a couple of different shaft couplers. One made of cast iron (first picture) and another made of steel (Seconf Picture). The steel ones should hold up better then the more brittle cast iron couplers.If this is a B&G circulator check to see which type you have.

EBEBRATT-Ed

They usually last a long while. Usually the springs break.

Jamie Hall

A repetitive failure like that is almost always something else… in this case, I would venture that there is a misalignment in there — could be either angular or lateral or both.

yellowdog

The rubber bearings at the end of the motor are probably shot causing misalignment. Happens a lot on the Tacos, not sure on a Bell and Gosset.

delcrossv

https://forum.heatinghelp.com/discussion/comment/1826450#Comment_1826450

Happens on B&G too. Usually caused by over oiling.

retiredguy

Over oiling causes the rubber washer/mounts to soften and allows the motor to sag which will cause coupler failure. Change the rubber mounts and that will probably fix your problem. Get the installation sheet for a new pump and motor and follow it to the letter to learn how much oil they need.

SuperTech

I would just replace the 3 piece circulator with a modern wet rotor circulator and then you never have to worry about oiling, alignment or replacement couplings.

mattmia2

https://forum.heatinghelp.com/discussion/comment/1826457#Comment_1826457

Unless it is a system with a lot of ferrous crud in it. You can buy a lot of wet rotor circulators for what a B&G 100 series costs.

hot_rod

bearing seizing up? Motors get oiled , sometimes the bearing gets missed

EdTheHeaterMan

The Red Circulator pump that has couplings failure is due to motor mount fatigue. this is the part number for the motor mounts for the B&G 100 series: 118223. Replace the two rubber motor mounts and the coupling will last longer. https://www.supplyhouse.com/Bell-Gossett-118223-Motor-Mount-Pack-of-2-Series-100-HV-2-Obs

After you replace the motor mounts, be careful when adding oil to the motor bearings. about 4 drops every season is enough. More than that and the oil will overflow from the bearing and drip on the the rubber mounts. That oil is what is making the motor mounts go bad.

Be sure that you have the 100 series motor. if you have the larger motor, the part number may be different.