"mcslinger" wrote in message
om...
I have a Myson Apollo boiler and a conventional heating and Ho****er
system.

I have recently replaced the pump (myson 53) with a new one
(circulation pumps 53)after it failed but now have the following
problem.

When the system is running a small amount of water is coming out of
the overflow from the small black plastic tank in the loft. I was told
the pump may be set too low so I increased it to the second setting
but this only increased the flow of water so I put it back.

Increasing the pump rate would likely make the problem worse.

One explanation might be a blockage in the system, cause by sludge, or radiator
valves (including lockshields) and zone valves not opening enough.

Rasing the maximum height of the overflow pipe might well be a way of solving
the problem, so that the vertical distance between the highest point of the
overflow pipe and the level of the water in the tank is increased.

Michael Chare