I have a Potterton Profile boiler, with a Grundfos Super Selectric pump. If the Central Heating has not been used for some time (through the summer months for example), the pump fails to start/work when the Central Heating is turned on.
I normally get around the problem by firing up the central heating/pump (for a couple of minutes) every two or three weeks during the summer, which has stopped the problem from re-occuring. However, this year I forgot to do this and the pump is not performing once again.
I get the impression the pump "locks up" through a lack of use, so would be grateful if anyone can advise how to get the pump working once again?

Slide Rule, September 2008

I have a grundfos pump on an apollo heat exchanger residential heating system. The pump sometimes freezes because the system is not used for many months at a time. Probably because it is a tiny pump only 1/25 HP. There is no easy access hole to manually turn the pump as suggested in a previous answer but it is a relatively easy task to remove the pump by turning off the water and removing 4 bolts. then you can manually turn the pump with your fingers. Replace the pump, turn on the water.

Home mechanic, December 2008

Tom,

Much appreciate your reply and advise/suggestion. Pleased to report this worked and central heating now back in action. Thanks very much again.

Slide Rule, September 2008

i have a peglers pump which may be slightly different to yours but i have the same issue after a long summer lay off to rectify the issue i have to remove the screw plate in the centre of the pump then into the hole you can insert a screwdriver and when its seated you turn the screwdriver and this manually revolves the impeller give it a couple of turns and this will unfreeze the pump and it should work as normal

tom 2, September 2008