Alpha CB24 with a leaking DHW Flow valve

[RustyNick]

Hello All,
I have a seven year old Alpha CB24 with a leaking DHW Flow valve.
It is mains water that is seeping through the vertical joint in the Flow valve, joint to side plate (All systems working fine, pressure good, leak stops when mains water isolated).
Tray under boiler captured about a pint over-night! Lime scale deposits indicate that joint has been weeping for a while, but has now got bad.
My dilemma is what to buy in the way of a seal kit before starting. Kits readily available on internet (and only about £15), but look to come with different types/sizes of ‘O’ rings etc, depending on what kit you buy (even though they all come under the 3.013389 number?)
Or, having read posts on fitting kits, and possibly having to remove Flow valve (And DHW Heat exchanger etc…) to get access to side plate, would it be safer bet (but more costly) to put whole new assembly on, while all the bits are off?
Also if removing DHW exchanger for access, what seals/washers will need to be replace to ensure water-tight replacement?
If anyone can recommend a kit for this job, that would be great (even better if I could find it locally to Oxford, I’ve missed last post before Xmas today with some places).
Or, if I’m barking up the wrong tree, please let me know, thanks.

 

[BingoBongo]

Can you take apic of where it is leaking as this would make it easier to advise on what washers you need.Im pretty sure the washer pack comes with the o rings for the hw hex but could be wrong.Paul barker is the man to ask

 

[RustyNick]

Hi, Thanks for the quick reply.
The attached picture shows the area of leak (red arrows down vertical joint).

Alpha Flow Valve leak

• RustyNick
• 17 Dec 2010
• 1

Front view and side view

I have carried out a quick bodge for the time being, seems to have stemmed the flow, not looking quite like Niagra! (opened up front two phillips screws-pushed bosswhite into hairline opening-screwed back up).

This has by no means properly addressed the issue, so am open eared for the correct direction to take (and parts to get), thanks.

 

[BingoBongo]

Had one leaking out the screws at the same bit.I changed the full valve.

 

[RustyNick]

Hello All, I now have a new Valve Assy ready to fit (Leak holding at present).
Fiber washers came with Assy, and lower fitted 'O' ring.

I still need new 'O' ring for rear of DHW HEX, for when re-fitting, and grease.

Can anybody advise me on type of grease, size of 'O' ring for HEX (or where to buy from), and any other washers/seals that will be needed for job of replacing the Flow valve Assy, thanks.