No hot water on Worcester Bosch 240 but heating ok

[john shobbrook]

Hello all, i have a problem with my combination boiler in that the hot water does not work although the radiators work perfectly. The hot water will however work if the Heaters have been on for a few hours but if the system is cold then i get no hot water at all. Also, when the heating has been on then the hot water i do get is not just the hot water from the heating system (at least i don't think it is), as it gets hotter and hotter the longer i leave the water tap running just as the it used to do.

Just to give you a bit of history on my system.
A few months ago i added another heater to the system but i did have a problem with the pressure relief valve leaking (just a few drops, but enough to drop the pressure on the system to below 1 overnight) when i first filled up the system (but the heating and hot water both worked great). I decided to try to fix this by replacing the pressure relief valve so before i read the installation instructions, i drained the complete system. I then read the instructions and realised that i did not have to do this so i refilled the system again and to my amazement, the leak had completely stopped which was great.
Anyway that is the history of my system which is about 4 years old.

Many thanks for any help given
John

 

[chrishutt]

Failed diaphragm in diverter valve? Looks like fairly straightforward repair, cheap spare part (if only diaphragm replaced).

 

[john shobbrook]

Thanks for the quick answer.
Does that job involve a lot of dismantling of parts in the system and is it a job that your average x-electrician who used to install and plumb in showers could handle?

Thanks
John

 

[ollski]

240 is a piece of cake, turn the stopcock off, drain the hot water tap and the diverter is staring at you behind the control panel, just undo the 8 screws and swap the diaphragm over.

 

[chrishutt]

The manual for the boiler will explain the procedure. Although I don't know these boilers as well as some, it looks straightforward to me and you shouldn't have any problems.