Hi, recently had a salamander ct85 xtra pump fitted to boost my hot water pressure, the problem i have is sometimes no hot water comes out of any tap, if i leave it several minute it will start and pump well, it as though it gets a air lock in the pump but my plumber cant fix the problem.
i have added a little sketch hopefully someone can shed some light on whats happening.
thanks in advance.

i have added a little sketch hopefully someone can shed some light on whats happening.
thanks in advance.
