My Grundfos UPS15-58FC has become a bit noisy when operational. Its a part of my heating system and it starts to hum from time to time and this causes the pipe its on to vibrate. I would like to try and bleed the air out of it. Correct me if I’m wrong but this seems to be the way to go with circulating pumps. Is it possible to bleed the air out of it? It seems to have plastic covering where the pump bleed screw would normally be and it says “With Check Valve”…I’m a bit lost - I was expecting a pump bleed screw and I’m not sure I see how a check valve prevents air from building up from the inlet. Can somebody please shed some light? I’m afraid of trying to pry out the plastic cover - it seems to be on very tight - in case that breaks the thing.
I found a manual bleed valve at the top of my water loop and I slowly turned the small nob on the side until a bit of water came out (circled at the top right), then screwed it back in. I also ran some hot water through the pump by opening the red valve (circled at the bottom left) which rests under the Grundfos (arrow points to the Grundfos). Will report back in a few days, or if anyone else has more suggestions, please feel free!