While you wait for answers, we may have found some information which could help you.
Success
Message
Cannot turn radiators off,?
Boiler over pressure on the hot-water side?
boiler starts then soon stops?
We have no hot water?
How can I fix my vailant boiler which is reading f.22 water shortage?
water dripping out of overflow pipe from boiler when CH on?
Vaillant turboMAX 824E?
HW issues w. Vaillant boiler?
dropping pressure on Vallaint 242E?
Diverter Valve Replacement?
Vaillant Turbomax 824 overheats very quickly in heating mode?
vaillant boiler trips house electrics when hot tap on?