Vaillant VCW 221 H no CH. DHW fine

[Agile]

I have a spare diverter valve somewhere in our stock of parts but have never needed it either.

The real expert on these boilers used to be Chris Hutt from bristol but we rarely see him after a brief and disasterous spell as Publicity officer for ARGI.

The very few that I get called to are simple faults and so far I have never had to deal with an interesting one!

Tony

 

[spacethegas]

diverters & ntcs do not go wrong with these boilers, full stop.

i cant think of any other parts on any other boiler that i could rely upon as much.

 

[tonybhoy]

diverters & ntcs do not go wrong with these boilers, full stop.

i cant think of any other parts on any other boiler that i could rely upon as much.

Honeywell grey button gas valve

Was at a boiler (Potterton Kingfisher 2 OF) I installed 14 years ago last Friday doing a service. This was the first time the boiler had been looked at since I fitted it and it was bleeding spotless,unbelievable.

Gas valve was a SIT and so was the TC which looked brand new. Astonishing.

Potterton couldn't spell the word boiler these days

 

[spacethegas]

changed hundreds of grey buttons.

never had the need to change either of the of the above ever.

 

[tonybhoy]

changed hundreds of grey buttons.

never had the need to change either of the either of the above ever.

Pretty impressive I have to say however the grey button valve must have been fitted in about 90% of UK boilers at one time or the other in it's various variants so it's fair to say that it was a pretty reliable valve,probably not as reliable as the old red and white button Honeywell valves though that was a different era.

Anyway sorry to digress

 

[spacethegas]

i agree.

but i am talking pretty much infallible.

nothing else i can think of can compare.

i recall going on the vaillant course when the second generation turbomax came out & they said the new diverter was bullet proof.

bo**ocx.

 

[namsag]

Changed a few ntc on them but not many, a few flame supervision boards on the E`s never had a fan go on one either
Loads of servo valves
About worst job on them is when the gland nut has been leaking for ages and it rots the grub screw in place and at worse knacke#s the entire bearing plate so the rod will not move through it at all.
Never not been able to split a water section though.
On the 221 the t/couple needs to be tight at both ends not just at gas valve end

 

[walerah]

i would check if the expansion vessel is sufficiently charged re the pressure rising.

...

thanks for the reassurance guys, I'll get to drilling out the screws this weekend and descaling.

the problem I'm now having is that the pressure rises intermittently, I have it at 1 bar but it seems to suddenly rise to 3+ breaching the PRV and dropping to 2 bar, I drain it back down to 1bar but it rises again.

regarding 'charging' the CH expansion vessel? what pressure I'm I looking for on it?

thanks

 

[Deleted member 105431]

ntc's, diverter valves and pcb's on the vcw are almost bullet proof. The servo and water valve are subject to wear and tear as are the aav. One of the most reliable and best boilers ever sold in the uk and was many years ahead of the competition.

 

[spacethegas]

//www.diynot.com/forums/viewtopic.php?p=251090#251090

don't worry if a little water comes out of the schrader valve as it is located at the bottom of the expansion vessel & may just be due to condensation.

 

[stevie p]

Hi everyone, we still have one of these boilers which is now 26 years old.
I'm attempting to solve a DHW problem myself, similar to which has been discussed in this old thread.
For the past few weeks we've had to very gently assist the cam on the servo to make contact with the microswitch. Sometimes it works fine for a day or two then sticks again.
I've stripped down the Servo today, which was scaled up and had a fair bit of sludge.
Problem I had was re-assembling the Servo as there seemed to be two positions in which the ceramic component could be placed - one enabling a small amount of travel and the other a much greater amount.
Also struggled to remove the two lower front Control Lines and I've squashed them a little after using pliers .
Put it all back together and no joy. Now when assisting the cam the pin does not rise from the Water valve at all !
Would the reduced inner diameter of the Control Lines be the cause or have I reassembled the servo the wrong way ?
Any advice would be very much appreciated

Steve

 

[DP]

Steve, why have you woken an eight year old post instead of starting a new one?

 

[stevie p]

Hi DP, I'm new here and perhaps I've gone about things the wrong way but the content of this old thread seemed relevant to my query

 

[Bunnyman]

Steve u have busted a part that never fails I'm afraid, get a new servo 012646, you maybe able to save the pipes, the problem lays with the water valve underneath. After 26 years the diaphragm is probably knackered hence you having to help the cam against the spring, best get a water section 011156 would do it, don't bother stripping valve as it will probably be seized solid

 

[stevie p]

Hi Bunny thanks for your reply. Apart from squashing two of the control pipes I don't think I've busted anything. The inner contents of the Servo are minimal , just a fan shaped ceramic weight which I think I've reassembled correctly .
I've already bought a replacement diaphragm for the water section but , same as a previous poster from 8 years ago , was unable to shift a couple of bolts /screws. Got to have another crack at it though first before shelling out - will take it to local motor rewind company I use for my work machines - they'll be used to removing stubborn screws.

Last November fitted a second hand main heat exchanger and was interested to see how blocked the old one would be so I cut it in half and there was no sludge or blockages at all