Help with Bell and Gossett 100 series circulating pump

circ_pump_help

Hi all, I am new to this message board, so please point me in the right direction if I am breaking any forum rules.

I have a gas boiler with the water circulated via a Bell and Gossett 100 series pump. Last year, right at the end of the season, the coupler went out. I didn't get around to replacing it until recently, and I also replaced the motor mounts while I was at it.

Upon hooking everything up, the pump is making a fairly loud ticking sound. I am having a hard time determining where it's coming from, but my guess would be that it is coming from the motor assembly rather than the bearing assembly. I can try to share a video of the sound the pump makes if that is helpful.
1. Does anyone know where the problem likely lies?
2. I have been reading that there are more modern replacements for this pump such as this Taco 007. Am I better off just replacing the whole pump rather than trying to fix and maintain the B&G 100?

Thanks in advance for any help.

Big Ed_4

Yes, the mounts of the motor go soft from over oiling and the off alignment of the shafts will chatter and break couplings . If the bearings wear and the shaft has play ,the motor needs to be replaced ...

Not knowing your system , but say it is a mono flow . A Grunfos may be a better match ..

hot_rod

We gat type of system? Hot water baseboard?

Robert_25

circ_pump_help said:

Hi all, I am new to this message board,

2. I have been reading that there are more modern replacements for this pump such as this Taco 007. Am I better off just replacing the whole pump rather than trying to fix and maintain the B&G 100? Thanks in advance for any help.

welcome.  If it were me, I would replace the circulator with a modern equivalent.  A Taco 007 is often used, but may not be the best choice for your system.

if you can tell us a bit more about the rest of the system we can point you to an appropriate replacement circulator.

hot_rod

I would go with one of the ECM type Every brands has them. You can dial them in to your systems needs

HVACNUT

Is it the correct coupling? No piece of old spring stuck somewhere making noise?
If it is bearing or motor related, then a wet rotor circulator is the way to go IMO.

EricPeterson

@circ_pump_help - I installed a series 100 in 1986 when we moved into our house and I rejiggered the near-boiler piping for the converted gravity system to pump away, etcetera.

I (finally) replaced the boiler in 2010 and kept the series 100, but it failed (like yours) with a broken coupler in 2013 on Christmas morning. With the help of my son-in-law, I replaced it with the NRF-22 that came with the boiler, and it has worked great since. The flange spacing for the two was the same which basically meant a drop-in replacement. Isolation valves for the win.

I later repaired the series 100 with a new coupler, but never tested it - it's been sitting in a box since then. So I might have had the same noise, I don't know.

I am happy with the NRF-22, it's quiet, reasonably priced, and requires no maintenance.

Eric Peterson

circ_pump_help

Thanks for all of responses, I had a busy weekend and was not able to respond till now. I have attached
some pictures, and below I respond to some questions.


I wish I could upload a video so you could hear the sound it's making. I am leaning toward ordering the B&G NRF-22 as suggested by Eric Peterson.

In order of resonses:

Big Ed_4 said:

If the bearings wear and the shaft has play ,the motor needs to be replaced ...

I believe this is what's going on.




if you can tell us a bit more about the rest of the system we can point you to an appropriate replacement circulator.

Its a baseboard register hydronic system in a fairly small, single level house, with 9 baseboard registers in 5 rooms run off of one thermostat.

HVACNUT said:

Is it the correct coupling? No piece of old spring stuck somewhere making noise?
If it is bearing or motor related, then a wet rotor circulator is the way to go IMO.

I'm pretty sure it's the correct coupling. The more I listen to it, the more I think it may be a bearing problem on the motor itself.

EricPeterson said:

I am happy with the NRF-22, it's quiet, reasonably priced, and requires no maintenance.

I am leaning toward ordering one of these today.

Intplm.

@circ_pump_help Have you lubricated the bearing assembly?

hot_rod

A NRF 25 is a better match, if you compare the curves, a 3 speed version

EricPeterson

hot_rod said:

A NRF 25 is a better match, if you compare the curves, a 3 speed version

Good point @hot_rod. I didn't mean to recommend the NRF-22.

I went through the process a while back of trying to pick the right pump by calculating GPM and head for my system. I determined EDR from here, from this Wall post determined my GPM of 24 and a 3.5 head.
Applying that to the pump charts this lands between the NRF-22 and the NRF-33.
Since I had the NRF-22 I went ahead and used it, and as I said it has worked fine.

But as it turns out, the NRF-25 (speed 3) looks like an even better match for my system. Maybe for yours too,

Eric Peterson

circ_pump_help

Intplm. said:

@circ_pump_help Have you lubricated the bearing assembly?

I have lubricated it. I may have over-lubricated it in the past, which I understand can cause problems.

circ_pump_help

Ok, thanks for all the help.
I have about 70 linear feet of baseboard radiators in the house. According to the link posted by Eric, this translates to 240 EDR, though I am not sure if I should adjust for the fact that my radiator pipes are not cast iron but rather copper pipes with aluminum fins.

Based on this, my system is off the charts on the small size in terms of GPM required. I think I'll go with the NRF-25 so that I have a little more flexibility with the variable speeds, and can match the output of the series 100 if I need to for some reason.

Thanks everyone, I really appreciate you taking time to help a stranger.

tim smith

Are you sure you put correct coupler on, their are heavy duty ones that will make noise on these smaller pumps. The correct coupler for that pump is Bell & Gosset 118705. Just fyi.

circ_pump_help

tim smith said:

Are you sure you put correct coupler on, their are heavy duty ones that will make noise on these smaller pumps. The correct coupler for that pump is Bell & Gosset 118705. Just fyi.

That's the one I got. Thanks for thinking of that though.

JUGHNE

Is it possible that you could remove the coupling or unbolt the motor from the coupling and run the motor by itself?

You might be able to sit the motor on a bucket, holding it in place to keep it from rolling away.

This might isolate the noise.

EdTheHeaterMan

replace the pump. it costs less to operate than the 1/12 HP B&G Motor. Lots of other problems solved that way too.