Hi i have got a Vaillant VCW GB 242EH boiler about 10 year old it's been brilliant but recently just today for no reason the CH has stopped working, when i had the hot water running(it was very hot as normal)but CH switched off i noticed the CH flow pipe was also hot but radiators cold. I turned off the hot water let the fan stop running so it was quiet then turned the CH on, the th'stat down to a low temp then up until it clicked which is the point the CH usualy switches on, but nothing, when i turn the hot water on the pin off the water section moves up ok & turns the servo valve cam to the micro switch, the pump & the fan switches on, the diverter valve moves to the right & the boiler fires up, so i presume the pin,cam & switch etc is all working, i read on a previous post that if the CH flow pipe gets hot with just DHW working that the diverter valve could be at fault but on another post it said the Vaillant boilers didn't use these as much so i could do with a few pointers, my info is basic as i know nothing about any boiler's except what i can see by watching it & the info off this forum, my backround is in a car parts dept. PS not sure about water or gas pressures i wouldn't know where to start however it has just stopped working & has been for the last 10 years so i can't see water/gas pressure to be a fault when the DHW is running the flames are a good height/colour & the water out the cold tap is at a good pressure so i would like to think they are ok. I take it i would be looking at one or more of the following, Diverter valve, water section or servo valve, oh also this system use to lose pressure so i was often topping it up off the cooling loop so any additives that was in the system all them years ago will probably be diluted to the point of it just being water without additive in the system, could this have any bearing on things many thank's sorry for the long post just wanted to get as much in as possible, regard's Stephen.
No CH but DHW is hot
- Thread starter Ste38
- Start date
Sponsored Links
If that boiler is 10 years old that makes me about 17.
Think about getting a new one!
Think about getting a new one!Sorry i worded that wrong i'm not sure how old the boiler is i should of said its at least 10 year old as there is a label inside saying it had some additive put in it in 2001 & not to drain so i kind of guessed the age off that , however i can't afford a new one at the moment & a lot of posts on this forum seem to rate this as still quite a reliable boiler & this is the 1st (&hopefully last fault i have with it)
, however i can't afford a new one at the moment & a lot of posts on this forum seem to rate this as still quite a reliable boiler & this is the 1st (&hopefully last fault i have with it) 
Sponsored Links
At least
All i can see on the diverter valve is the top & bottom (red) micro switches with a plastic cover over them, it is at the lower right as you look at the boiler, the switches are pressed by 2 pins on a plate which moves to the right as the DHW is switched on, the DHW pin being the lower spring loaded one i think, it kind sits below the HEX Exp valve, i just was after a few pointers to see if it's something i can sort myself any help appreciated, the boiler could be 15 years old it was in the house when i moved in
Most boilers of that model that I see have serious leaking issues!
Just one needed an adjustment of the microswitches to get it working!
But the drunk Sri Lankan landlord just wanted it working and did not want the leaks fixed. I felt sorry for the poor tenant!
Tony
Just one needed an adjustment of the microswitches to get it working!
But the drunk Sri Lankan landlord just wanted it working and did not want the leaks fixed. I felt sorry for the poor tenant!
Tony
Hi which micro switch is it the top red one?? ive pressed that in but it doesnt make a difference the boiler just doesn't fire up when trying to use the CH. I cant see any leaks it had a one a while ago which has since stopped it seemed to be coming out of the auto air bleeder at the top & dripping down onto the pipe on the top of the pump but i notice the bleed screw in the auto air bleeder was a slightly tight & according to the label it should be slackened off a couple of turns which i did, since then the boiler holds good pressure & no visible leaks PS not sure if it's any relevance but it's still got the old style red/orange plastic heat exchanger in??
when trying to use the CH. I cant see any leaks it had a one a while ago which has since stopped it seemed to be coming out of the auto air bleeder at the top & dripping down onto the pipe on the top of the pump but i notice the bleed screw in the auto air bleeder was a slightly tight & according to the label it should be slackened off a couple of turns which i did, since then the boiler holds good pressure & no visible leaks PS not sure if it's any relevance but it's still got the old style red/orange plastic heat exchanger in??The only relevance is that it just demonstrates the age! They were a serious leak risk. So much that they produced a metal conversion replacement.
Never seen a red one though! Always black and discoloured by the water leaking!
It was a long while ago and I was distracted by the nice tenant lady. So I dont remember which switches were involved. I remember the lady more though.
Whenever I am called about one of that model I usually recommend boiler replacement.
Tony
Never seen a red one though! Always black and discoloured by the water leaking!
It was a long while ago and I was distracted by the nice tenant lady. So I dont remember which switches were involved. I remember the lady more though.
Whenever I am called about one of that model I usually recommend boiler replacement.
Tony
What country did she comes from? .
.DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
Sponsored Links
