B&G 100 series pump leak after new replacement parts

rfhjr

I replaced the seal kit, motor mounts, and put a new gasket on a 100 series B&G pump used on a propane boiler because it was leaking. It still has a slow drip sometimes at other times there is no drip but it is an improvement from before the parts were replaced. I checked the bolts and they are as tight as they can be as I did not want to crack anything. The only part I did not replace, since I did not have one, was the bearing assembly which had some circular etching on the shaft which I sanded out as much as I could. The drip is originating from where the assembly bolts to the pump body. Just was curious if the etching on the bearing assembly could be causing the drip or should I just take the mount off clean the surfaces and use another new gasket.

ScottSecor

On series 100 circulators the leaks almost always occur at the bearing assembly. The internal seals often get worn from the solids in the boiler water (rust, minerals, etc). Over time the face of the seals allow liquid to "slip" between the two surfaces and water will leak out of the shaft. Most of the time the water leaks on the motor end of the bearing assembly. However, sometimes the water leaks out of the center of the bearing assembly where the wick and large oil fill cap are located.

Most likely you need a rather expensive bearing assembly. Make sure you replace the thin gasket that goes in between the veloute and the bearing assembly.

Another choice it do replace the series 100 circulator with a wet rotor unit. Might be cheaper in the long run and they don't require maintenance.

ScottSecor

I apologize. I missed the fact that you already replaced the seal kit. I'm guessing the shaft is pitted and allowing water to pass by.

You could try to replacing the entire bearing assembly or replacing the entire pump as suggested earlier.

For smaller circulators like the 100 series, we stopped replacing seals long ago as the time it takes to make the repairs is hard to justify.

mattmia2

If the system has a lot of debris in it and especially ferromagnetic debris, the 100 series will tolerate that better than wet rotor pumps so that might be a reason to repair it. another option in that case would be a magnetic dirt separator and a wet rotor circulator