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 last november 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, 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, the hot water had been turned right down and the water temperature was lower. The heating worked fine but the water was only luke warm,.

turned up the water and it was ok for a bit 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 wrong 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?

At my wits end!, February 2007

My vaillant 242 works perfecly but flu fan does no shut down ? James

James Balchin, October 2016

On this Vaillant it will be the flame detection electrode. Over time the electrode warps from the heat. Replacement comes as one unit held on the burner by 2 screws. job for a gas safe installer though as i'd also check the burner pressure after fitting.

BG, February 2010

Did anyone find out what the problem was here? Thanks

Vaillant 282, December 2009

can be a few things. the thermistor should have cured it. but these boilers are about 15 years old and the average life of a boiler is 10yrs so its prob time to replace it.

ric o'shea, April 2008

almost certain that prob is with differential pressure switch on gas valve.it has small pipes going to and from it and these can block up or the diaphram can perish(less likely). Only corgi eng should deal with this problem .most engineers dont understand how these older boilers work though, so find one that knows whatswhat before employing them

mr gas, February 2007

hello m8, the vaillant 242 EH is still a good boiler, there is still a good few years left in this boiler, but if you dont understand how they work (about 50% of engineers) then you are scuppered, sounds poosibly could be your diaphragm pump, this is atiny air pump, that gives air pressure to the gas valve, to raise it to high flame, do yoursef a favour tho, if you want to keep your boiler, call british gas go on thier homecare plan you boiler will be fixed by wednesday.

Mark, February 2007

Vaillant said they are unlikely to be able to fix a boiler of that age and suggested I get a new one!

witzend, February 2007

Have you spoken to valllant themselves the local guy was on 0217888282 some years ago and was really great he arrived in two hours on Xmas eve best of luck

Roy Dacre, February 2007