the boiler was power flushed as it used to be cut off. Even after flushing the problem remains the same.
A by-pass has recently been installed without any improvement. Please advice to sort out this cutting problem.

Yash Seth, March 2009

if the overheat keeps tripping, then the pump overrun thermostat may be faulty. bring the system up to temperature, turn it off on the timer and see how long the pump runs on for. if it stops straight away it may be faulty at faulty pump overrun thermostat or the boiler may not be wiring in correctly

Paul the gasman, March 2009