Series 100 Bell & Gossett Circulator Leak

MrCofDG

My boiler system has two Series 100 B&G circulators. Both running fine this heating season. Couple days ago I noticed one circ (1st floor's) was leaking (drop every 5 seconds) from the bottom of the seam between the bearing assembly and the pump body. Got a new body gasket; drained system, pulled out circ from pump body, replaced the body gasket, put circ back in. Refilled system. No dripping; good. Turned on t-stat. I hear that "pipe-shuddering" sound that I know - from 2019 experience with the other circ - is associated with a bad bearing assembly/stuck impeller. I was stunned - could its bearing assembly really have gone bad ?? I mean that 1st floor circ was working this morning..... Any ideas appreciated!

delcrossv

Water probably got into your bearing. Did you remove the cover and inspect the bearing when you had it out? Been keeping up with the oiling? Also sometimes the wicking gets dislodged if the assembly is inverted when you're working on it.

MrCofDG

Yes, did the oiling at start of season. Did not remove cover/inspect bearing. Are you suggesting the bearing was (due to water getting into the bearing) on the verge of failing just before I pulled the circ out of the pump body ?

MrCofDG

One other data point - the circ was new in 2010.

EdTheHeaterMan

Some of those B&G 100 circulators are overkill for the application. The wet rotor Taco 007 pump curve intersects the B&G 100 curve at about the midpoint of each pumps range. Perhaps a replacement pump is in order since the Taco pump is usually less that a B&G bearing assembly.

Look at this pump curve chart from Taco with the B&G 100 added to it.



Pretty close. The whole discussion can be found here https://forum.heatinghelp.com/discussion/160802/replace-b-g-100-or-use-taco-007-monoflo

MrCofDG

My concern with wet rotor circs is that they need (i've heard) to have water that is free from metallic/ferrous particles; and i have fairly old cast iron radiators.......

EdTheHeaterMan

I have seen Taco 007 pumps on those old cast iron systems work just fine for years. They are inexpensive compared to the 3 piece pumps and have less maintenance. Or you could just purchase a new pump seal only and rebuild the one you have.




https://www.supplyhouse.com/Bell-Gossett-118681LF-Seal-Kit-No-7-Lead-Free-Buna?gclid=Cj0KCQiA-qGNBhD3ARIsAO_o7ynIJqRiEaw8nBcwSUIu8Io3MYVIAslgcNJ5n9wdpJB3O5qAbMMNp5oaAoipEALw_wcB

delcrossv

MrCofDG said:

Yes, did the oiling at start of season. Did not remove cover/inspect bearing. Are you suggesting the bearing was (due to water getting into the bearing) on the verge of failing just before I pulled the circ out of the pump body ?

It happened at my folks' house on one of their 100's. First the dripping then the squeal. There was water in the bearing box. Another one leaked for a couple of weeks and was fine with just a new seal.

I've had a low opinion of Taco pumps, but my MIL has one as DHW circulator and it's worked fine with crud filled, century old galvanized pipes for years.😎

MrCofDG

Gents, turns out there was water in the bearing box. Either happened before I saw the leak, or maybe, my deinstall/reinstall possibly induced it. More to come; having a pro do the work now.

HVACNUT

Lose the 3 piece. 

MrCofDG

And the Series 100 is gone. Went with a Grundfos circulator. Thanks for the inputs.