Grundfos Alpha

ChasMan

When you remove the head of a Grundfoss Alpha, you can pull the Impeller out and behind the impeller is a round stainless steel rotor can. When I shake it, There is fluid in it. Is it normal for that to have water in it? It seems somewhat unusual that the water is in there but it won't drip out? Never took a pump apart before. This one was giving me fits yesterday so I disasembled it.

Paul Pollets

Why?

What was the pump doing that inspired you to take it apart?

ChasMan

Two Reasons

I could not get it to start. I had this issue earlier and managed to get it to start by purging water through it and it seemed to be fine but this time, it just wouldn't move water. I have two of them and this one was acting strange. It would show 13W 0 GPM on fixed speed three. No water was flowing.

The other reason I removed it was that it seems to me, after installing these two pumps I started to have air issues. I'm not sure if they are related so I was just switching my changes back one at a time to see if my air issues will get resolved.

pipe4zen

Alpha

I recently had a no heat callback , and found one my Alpha pumps has a 0gpm on fixed speed also. I eneded removing the head and found sticky impeller, I WD40'd the shaft and worked it free.



Typically I only use fixed speed or pressure diff. modes, I find the autoadapt feature to quirky as far as flow goes.



I don't see how the pump itself could allow air into a system.

ChasMan

Flakey

Well, I couldn't see it either. I haven't checked in a couple of days but I don't think the air issues were solved by swapping it out. I have one more pump and a spiro top to swap out to put the system back the way it was. I'm starting to suspect that spirotop for some reason. The impeller didn't appear to be sticky. It's sitting in it's box with an RMA number on it now.  

Jean-David Beyer

Transparant top for Spirovent and Taco 49-xxx series air eliminators?

I doubt they make these with transparent tops, but it would help in deciding if the vent valve in the top was working or not. It might even tell you how fast it was accumulating-removing air from the system. I wonder if there are any transparent plastics that are strong enough to resist water and propylene glycol at temperatures up to 250F, and are easily cast and machined, and cheap enough compared to brass. ... and resist someone over tightening the fittings.

ChasMan

Hand Blown

I would buy one. Hand blown glass boiler vents.

I just finished capping it off.