My Grundfos pump was making a "train chugging" sound so I had someone come replace it. After about a week, it started making the sound again. I called the plumber and he told me to bleed the system to get the air out. I tried that but it still makes the sound. It's not all the time, just once in a while but it's loud and you can hear it throughout the house. I have it come on at 6am and this morning was bad.
I don't think he knows what is causing it as he won't contact me after I asked him to come back and look. Before I call someone else, does anyone know what is causing this or how maybe I can fix it myself?
This forum won't let me post links so I'll respond to my post with the video.