Hi There, I have recently replaced my shower system with a thermostatic valve. I have a gas bolier in the kitchen about 10 years old. When I turn the shower on it's eithe rtoo hot or too cold. The boiler will only fire up when I turn the hot water tap on full. As soon as I turn the tap to balance the temperature with a little cold water, the boiler switches off and the water is cold again. The plumber has told me that, to shower I will need to have the central heating switched on while I shower and switched off when finished. Is this correct? Is there no way we can fix this issue. Grateful if you can shine a ligh ton this..

Kevo, April 2009

Hi STE,

It's a SIME Super 90 Mk II.
I am not sure if he's checked the divertor valve or flow switches. I will check with him.

It's a pain in the butt switching the central heating on before showering eveyday.

Hope I dont need to change the boiler? :(

Cheers

Kevo, April 2009

what boiler do you have? has the engineer checked the operation of the diverter valve and flow switches

STE, April 2009

Hi STE,

Thank you for your reponse.
The main cold water pressure is pretty strong. And i do have a combi boiler.

Cheers

Kevo, April 2009

whats your main cold water pressure like if its low you will share the supply to boiler with the shower causinf the boiler to overheat and cut out on the water side, i'm guessing its a combi you have

STE, April 2009