tinted hot water.....Valliant combi-boier problem

[synthiaks]

i've recently had a problem with my combi-boiler (Valliant) in that it is constantly heating water/working the central heating.....even with the selector switch set to water only. the water pressure rises from the usual 1.5 bar up to around 2.5 sometimes, the thermostat doesn't effect it either.


also, there is a rust-coloured tint to the hot water! the tint varies in strength and sometimes dissappears, i've also had it show in the cold water but i assume this was cross contamination via the hot.


any ideas what could be causung all or any of this?????

 

[Nixt]

You have an internal leak in the dhw heat exchanger which needs replacing. To confirm watch if pressure rise occurs worse late at night with boiler off.

 

[Agile]

Or turn off the cold feed to the boiler and see that the pressure does NOT increase!

Tony