I have a vaillant vcw gb 242 eh boiler that was already in my flat when i bought it, i have no idea how old it is but it worked fine. then a couple of months ago it started trying to ignite over and over again for both hot water and central heating, then cut out as it couldnt ignite. Got a corgi repair man out and he took the boiler apart, sat in the room on his mobile phone for ages, put it back together and said he cleaned an electrode as the boiler was cutting off when it got too hot as the flame sensor electrode was dirty and the boiler was not igniting when it got too hot. Charged me and left, I have not got a user manual so not sure what it is for but there is a knob on the bottom of it with a thermometer picture on it that can't be turned, this has been turned right down and the water temperature is now lower. The heating works fine but the water is only luke warm, tried ringing him back but he reckons its nothing to do with what he did as he didnt change anything to do with temperature. I don't know much about boilers but as i have been ripped off in the past was hoping someone could give me an idea of what might cause it and if it could at all be linked to the temperature knob thing being turned down? i just thought if it was over heating and the temperature was turned down it might not over heat anymore and this might be why the CH works now.

I know this post sounds woolly and i have no intention of burning down my house or blowing myself up by doing it myself! just don't want to be messed around or ripped off.

Also, if anyone knows where i could get a user guide that would be good.
All advice appreciated.

Clueless about boilers, November 2006

Arghhh! sorry but I am at my wits end with the blasted thing now, turned up the water as suggested above (dont you just love WD40) then last month the water went luke warm again, couldnt turn the water temp up any more so got an engineer out, the gas pressure was low so he charged me £50 to adjust the gas pressure. Then he went, seemed ok but about 12 hours later the ignition started clicking but the gas wouldnt light. It was going off then relighting quiclkly. the water was going hot and cold. Central heating was fine. he came back and adjusted it again, then the water was fine but the central heating kept going off and triping the safety switch on the front of the boiler. came back and changed the thermistor and adjusted it again, worked for two days now its started the old problem of trying to ignite over and over and then tripping the switch on the front. It is ok on low heat central heating and the waters is ok for a while if the heating hasnt been on but otherwise just switches itself off. I had paid another £90 for the final 2 visits but its not fixed. i have found a few posts on other forums citing the same problem with this boiler but everyone says they will only post an answer if emailed a corgi number. I dont want to fix it myself, just a vague idea of what might be worng as i am fed up of paying out call out charges for the problem not to be fixed. Please can anyone point me in the right direction of a possible cause of this type of fault?

The most annoying thing is I am planning to get a new boiler soon anyway and had savednearly enough money, now its all going to go on getting the darn thing fixed.

Clueless about boilers., February 2007

had same problem today.Boiler lights for about 5 sec, then goes out Ive ordered a new flame electrode, will let you know what happens. think you can download instructions from vaillant web site

simon, November 2006

THE KNOB ON THE BOTTOM IS FOR THE WATER TEMPERATURE ONLY SO WONT AFFECT THE HEATING, THEY ALWAYS STICK, YOU COULD UNSCREW THE KNOB( 1 SCREW) THEN SPRAY ON SOME WD40 AND TRY WITH A PAIR OF PLIERS/GRIPS. I WILL WARN YOU THAT SOMETIMES THIS CAN CAUSE A SLIGHT DRIP FROM THE SPINDLE BUT NOT ALWAYS. IF YOU ARE IN ANY DOUBT, BRITISH GAS WILL RECTIFY ANY FAULT FOR A ONE OFF FEE OF ABOUT £150. TRY IT YOURSELF, IF NOT, PHONE THE EXPERTS

BG MIKE, November 2006