Sounds like the pump is not working.
Check that the pump is getting 240 volts as it could be programmer or roomstat faulty.
Hot water could be on gravity system and not need pump to work.
Hi I have a customer who has managed to lose the chrome knob off her bath, it has been totally tiled in so changing the whole thing would be difficult. The bath is a phoenix as you can see but the filler could be any make. Does any one recognise the backplate so that I can get a match for this...
Check the pump speed it may be set too low, it may be worth fitting a balancing valve on the return from the cylinder, however if the heating works on heating only it should work just as well when the hot water demand is satisfied and the mid position valve returns to heating only.
If you have removed the allen screw the handle should lift straight off no need to be in a certain position.This will expose the top of the cartridge.
The cartridge usually has a retaining nut which you undo to enable you to remove the cartridge.Make sure you have isolated the hot and cold to...