My linea 24 Central Heating is working fine.

Hot Water is only giving luke warm, temp. is at 34 degrees. but when
flow at tap is closed the temp shoots up to 90 deg. on boiler display.

I have noticed that the 22mm pipe that connects to "Diverter Valve
Manifold" (main brass housing at bottom left) is very hot indeed, But
the Domestic Heat Exchanger (DHE) body is luke warm. Same as the Hot
water outflow pipe. As soon as the tap is closed, the temp shoots up to
90 and the DHE begins to get hot to same temp as main feed pipe.


I have checked:
The water pressure at mains
Motorised Valve

I have replaced:
domestic heat exchanger
thermister on main heat exchanger.
thermostat switch on main heat exchanger.
thermister near dhw heat exchanger.
non return valve on bottom right of dhw heat exchanger.
Also replaced the valve bobbin in diverter valve (bottom left, located
behind motorised valve).
Also replaced the water pressure switch, But have not touched the
adjustable plastic screw heads on this switch.


Many thanks for your help.