While you wait for answers, we may have found some information which could help you.
Success
Message
Unexplained noises?
Heating?
Turn dial which way to increase speed?
Grundfos 1550 ch pump installation?
Grundfos Pump Plan wiring Centre part 96437234?
Problem after changing ch pump on a grundfos pump plan?
baxi 105 HE boiler problem?
grundfos selectric 15-50?
how can I fix my old glow worm central heating boiler model 65-80?
grundfos MK 2 15/50 x 18 playing me for a fool?
Grundfos UPS 15 45 x18 central heating pump?
pump diagram?