HEATING ON .. HOT WATER YES, HEATING OFF .. NO HOT WATER

[wbmkk]

I have a Baxi 105 boiler

A plumber has serviced this recently and I assumed all was ok

However, if the CH is not turned on, there is no hot water at all

If the CH is on, there is

Now that would be OK (as a temporary measure) if it was mid December, but not really great in April.

What's going on ?

Many thanks for any advice

 

[twgas]

diaphagm most likely,

 

[totalshell]

diaphragm

 

[ollski]

//www.diynot.com/forums/viewtopic.php?t=133431