Grundfos 10-16

Kerrystarnes

The pump is making wla whirring noise. Is there any maint. I need to do or is it starting to fail? Also does the newer 10-16a model fit in same pump housing and a good replacement?

hot_rod

A super simple circulator to service.

Turn off water and drain pressure at a faucet. A supersized channel lock pliers works best.

Loosen the large brass ring to remove the motor.

The small impeller may have crud in it, just lift it off the stem, it rides on a stationary ceramic, or stainless shaft that doesn't spin.

Use a Kleenex to clean out the chamber and outside of the 1/2 ball shaped impeller

It is a magnetic drive type of circulator, that impeller just rides on that shaft.