Worcester 240 Boiler

[Space-monkey]

I have just moved into a property with a Worcester 240 boiler which seems to have a few problems. Firstly, when taking a shower the temperature does not stay stable. It goes from hot to cold. The pressure gauge shows below 1. When running hot water the central heating comes on even though it is switched off at the boiler. Also, the overheat thermostat keeps tripping. Any idea's how to fix these problems cheaply?!

[Nick.Detroit]

It's 99% likely to be the ''diverter valve'' .. i had exactly the problems you describe and that's what they changed ...