Grundfos UPS 3 pump - blocked message

[Huw Evans]

I have moved into a house which uses a Grundfos UPS 3 pump to circulate the water in a wet underfloor heating system. Last autumn the pump would not start - the blocked message showed - so I replaced it. This year, the same thing has happened with the new pump. I have freed the impeller using a screwdriver as advised in the instructions but the red and orange error signal still appears. Any suggestions ?

 

[ShaunCorbs]

Screwdriver in the centre and give it a wack inwards

 

[Huw Evans]

Screwdriver in the centre and give it a wack inwards

Thanks very much. I also took the pump apart and, although I could not see what was sticking, it worked when I put it back together. Happy days - for the time being !

 

[ShaunCorbs]

It’s a common problem they don’t like not working for months best to turn it on and run it once a month