Aquaextreme 50Z
 

Just got one of these, and it sounds as if its refusing to bleed... What do they sound like when they're bled properly? very low hum?

Cut the hose lengths shorter and used hoseclamps, (thought air might have been coming in from the suction side) but it did little to help. Im going to run a straight pump - pump loop with a T line now to see if it'll make a difference.

I'll inspect the impeller shortly... Anyone had experience with these? whats the difference between these and the mcp600? I believe the mcp600 had a newly machined front end?

I'm not sure if my Mag3 is properly bled either. It sounds like I have a tiny bit of air in it too. I understand the motor is rather loud but it definitely sounds like I have air in it and I'll be damned if I can get it out. Good luck.

Did a retighten of the housing, reseated the hosing and clamped them harder than i did before (not a fan of clamping them hard, being plastic and all) and after a while it seemed to get a lot quieter. If i apply some restriction to the loop it quietens down; i guess theres some impeller movement with little loading, so hopefully with blocks etc installed it should be nice and quiet.

The pump might be cavitating due to lack of back-pressure. It should quiet down definitely with a block in the system.

My mag3 also makes a little noise with no restriction.