When I finally get the pilot light to stay on, nothing happens when I put the electric back on and turn thermostat to Low/High with water & CH to constant.
If I fiddle around with 'ignitor' box underneath on the left hand side, the pilot light goes out.

Jeremy, December 2008

Chances are the solenoid on the gasvalve has gone.Check across the gasvalve and see if 240 volts are there.If it is then the solenoid operator has gone.The myson has a thermocouple with an interupter fitted so it could be the t/couple,especially if as you are saying its hard to keep relit.

Tony S, December 2008