Boiler Potterton Profile 60el?

sounds like you have an airlock maybe in the pump and it's activated the overheat stat. so your having to wait for the boiler to cool before it will resart.
try bleeding the pump there is a nut in the centre remove that and the air should free, just hold a rag under pump to catch slight bit of water that comes out.

hi-spec plumbing
July 2007