Water overheating

[Grandpa]

Hello, Advice please. I have a Worcester Heatslave 20/25 which has suddenly decided to produce domestic water at near boiling point. I've turned down the water temperature control but it doesn't seem to have made any difference. The boiler was serviced two weeks ago and the control panel replaced because the display had failed.

Any idea what the problem could be and can I fix it?
Regards
Grandpa

 

[kimbo]

Sunds like the DHW thermostat needs replacing

 

[Grandpa]

Sunds like the DHW thermostat needs replacing

Thanks kimbo. DHW stands for ..... Direct Hot Water? Can I change it myself as a resonably competent DIYer or should I really get an engineer?

 

[kimbo]

Yes should be fairly easy, I would check the temperature with a thermometer but it would be sufficient to turn the dial up and down and you should hear it click, if it doesnt it is usually faulty.Pull of the knob undo the two screws and disconnect the wires with spade ends in reverse order. Fit new and dont forget to insert phial fully in.Try heating world of spares for the part.

 

[Grandpa]

Brilliant. Many thanks Kimbo.