i have a vaillant ecomax combi boiler,every now and then it shows me the fault code f.25.in the book this says its something to do with the water switch.how do i fix it.sometimes i may be using shower and the shower will go cold,i look at boiler and it says F.25.sometimes when the fault code shows F.25 the pressure may be normal (2-3) sometimes when it shows F.25 the pressure is zero.can you help please.

a murphy, May 2008

Gareths tip worked, but had to open both valves, it rose very quickly so stay watching it! This website (and Gareth) just saved me £250 call out from Vaillant. Thanks to all

Alisdair Cruchley, September 2009

At the bottom/underneath your boiler you will see 2 black switches. 1 to the right and the other slightly to the left! As you can see your pressure dial is at zero! You need to increase the pressure by turning the switch to the left, this will increase the pressure and bring back your hot water. insure that you do not pass the green and go int the red on your pressure dial. Check after about 20 mins to see if the pressure dial has gone up past the green, if so bleed your radiators untill back to green. Hope this works.

Gareth Fuller, January 2009