My grundfos alpha2 15-55f circulator not pumping

y3ukhon

Hi. I got this unit 3 year ago. Winter is coming so I turned on the heat recently. I found the middle one not working. There is no water pumping from what I can hear. The display ends up in "- -" sign, similar to what some people discussed on YouTube. ( https://www.youtube.com/shorts/biuCKxLga2A?app=desktop )

Tried their solution but upon uncovering the cover, I don't see anything allows me to remove the middle silver thing lol

I am not a plumber so I don't want to make more mess/yank and break my circulator.

Anyone has experience with this particular version?

Larry (from OSHA)

I replaced mine earlier this year after about 10 years of operation. Mine did the exact same thing as yours and no way to get it to run. This is what I got and it is the new and improved model. Hope this helps you.

https://www.supplyhouse.com/Grundfos-92603115-ALPHA-15-58F-Smart-ECM-High-Efficiency-Circulator-Pump-with-Optimized-Setpoint-Control

y3ukhon

https://forum.heatinghelp.com/discussion/comment/1814778#Comment_1814778

Hi thanks

Are you aware of how to open up the middle?

My dad is thinking to replace this unit with one of the regular circulator from homedepot lol. Not that I am against more affordable version but want to see if i can still fix this one. Considering only 3 years…

EdTheHeaterMan

I might try this first. It can't hurt and it may solve the problem.

HomerJSmith

The rotor is heavily magnetized. If ferrous materials gets into the rotor area, it can lock up the rotor and keep it from turning. You can remove the rotor-impeller and check the rotor for magnetic, ferrous, debris. If found, use duct tape and remove it and re-assemble the pump. The impeller should rotate freely.

hot_rod

The allen headed cap screws take a 4 mm allen, a 5/32 T handle works also.

Next remove the rotor can from inside the motor, does the impeller turn?

If not the rotor can be removed from the can with a couple thin blades. Carefully. There is a flat rubber gasket in there.

If the inside is covered with black articles, you have magnetite plugging those pumps.

Screenshot 2024-10-17 at 1.59.45 PM.png

Screenshot 2024-10-17 at 2.00.05 PM.png

Screenshot 2024-10-17 at 2.00.14 PM.png

y3ukhon

https://forum.heatinghelp.com/discussion/comment/1814798#Comment_1814798

Thanks, will try this again. I didn't shut off the bototm, probably why it was spilling hot water the moment I tried to unscrew the top lol

y3ukhon

https://forum.heatinghelp.com/discussion/comment/1814817#Comment_1814817

wow so looks like the version i am on has removed the ability to do this from the front and would require me to take the whole motor out after unscrewing? wow…

hot_rod

correct , some versions have that large screw slot plug that gives you access to the shaft. Others are plugged.
It may have been a liability issue as you can get a blast of steam out of that plug if the pump has been powered while locked up.

Basically you boil the water in the rotor can

It better to pull the motor to see if it is stuck and maybe discover the cause

Handle with care, the shaft on those Grundfos are ceramic, they break easily if dropped