Fix Fault Turbomax

vailliant turbomax plus 824e combi boiler, intermittent fault on domestic hot water supply, fails to come on when called for sometimes, have changed all three NTC,s flow, return and warm start it was ... more

Vaillant Turbomax pro. The central heating will not come on but the hot water is working ok

I keep losing the domestic hot water when the central heating is on. I can only get it back by turning off the c/heating for a few minutes, it then returns I can then put the c/heating on and everythi ... more

Do I turn the filling valve to increase the pressure, clockwise or anticlockwise? The filling valve key is absolutely tight - unable to turn at all. Any suggestion please. Thank you.