Vaillant VCW 221 H no CH. DHW fine

[Agile]

Of course we don't encourage any DIYers to open the combustion area for any reason at all if they are not gas safe registered.

That is because the combustion parameters need to be checked afterwards to ensure safety.

Tony

 

[Bunnyman]

Are u drunk again tony ffs?
We can only guide u mate, i have mended thousands over 35 years, your servo will leak, spend £150 an save your pain and gain a few years,

 

[stevie p]

Bunny, I see you live in the same county as me - are you still in business ? Are you near Wellingboro' ?

 

[stevie p]

Update.
Sorted the squashed tubes by gently pinching them back into shape with mole grips.
Pig of a job to remove 3 of the 5 bolts to the water valve, even with heat applied, but got them out eventually.
The diaphragm had a hole about 2mm diameter near edge and a 12 mm tear also near edge, and was very worn out after 26 years service !
Fitted new diaphragm and new bolts and put it all back together and it leaked via the stuffing box but it worked - boiler fired up and DHW and heating worked fine.
Took the water valve off again and fitted a new stuffing box and that stopped the leaks completely.
However now the servo cam doesn't return to the off position when DHW is turned off !!
The push rod in the servo mounting plate is lubricated and free moving and the water valve internal spring that helps the pin withdraw has plenty of tension in it. Even pushing the cam down with finger wont make it return. Having to switch power to boiler off now to stop pump running.
Any ideas folks ?

 

[AGAS]

well you should of listened to what the bunneyman has said but their isn't telling some people , as you can see from his avatar he works for vaillant .

 

[stevie p]

I did take on board what Bunnyman advised but if I can save £ 125 by trying a new diaphragm first I will do. It's only 5 screws to take a look inside . Is that okay with you ?

 

[AGAS]

NO
honestly if someone works on an appliances from same make 24/7 i would think they would know what there talking about , i don't know if you can get the spring separate you maybe lucky ( if thats the problem ) i have had a look for you to find what you need ,(considering how long you've been working on it) I've been looking for last 15 mins but no luck . hopefully the bunnyman maybe able to give advice later .

 

[Bunnyman]

I take it now you have no heating ? Yes you need a new water section , the flow reg is now jammed.

 

[Steelmasons]

Gotta love these cheap skates....ALWAYS costs them more in the end..

 

[Terry7556]

If there was a way to save you the cost of the water section , the bunnym an would have suggested it to you. That is the sort of fellow he is, giving up his free time and knowledge to help others out.
You on the other hand decided that you did not need to accept that advice

 

[stevie p]

I enjoy taking things apart and trying to see how they work , solve the problem and save money. WTF is wrong with that ?

Terry, if you read above again you'll see I asked if he lived locally - why do you think I asked that ?
I opened up a water valve, replaced a punctured diaphragm and a leaking stuffing box all for £12 - defo worth a try in my book - I was also curious to see what was inside - sorry for that

 

[AGAS]

I enjoy taking things apart and trying to see how they work , solve the problem and save money. WTF is wrong with that ?

only problem with that is you can wreck parts while fiddling so you only cause more work and money for yourself .

 

[stevie p]

AGAS, the external spring on the cam and the spring inside the water valve are both fine thanks.
It's the water pressure on the diaphragm because the flow reg' inside the water valve is sticking/ jammed , as bunny suggested if I understand him correctly , that's preventing the cam from returning. That spring loaded component was not very smooth when I first opened it up but I thought I'd freed it up by lubricating it , and seemed to be functioning well before I reassembled the water valve.

The Vaillant manual advises - "Remove 5 screws securing the 2 halves of the water section. Check diaphragm and replace if necessary. Clean water filter. Check stuffing box and replace if necessary. Reassemble in reverse order."

 

[AGAS]

ill have a look for you , i haven't got much info on this boiler from my notes

 

[AGAS]

whats the g.c number of the boiler , it should be on the data label on boiler somewhere