Replacing heat exchanger - Vaillant

[ChrisLLLL]

Hi
Any advice on replacing the heat exchanger on a Vaillant VCW 25/1 T3W H please?

Basically, there is a hole burnt in the thin metal skin between the pipes. Boiler works fine apart from this.

British Gas helpfully told me today to pay £3000 for a replacement boiler !!! I know this part can be replaced... but don't know the details / pitfalls. I already installed a heating system (that worked) so I think I can cope with this job....

Does anyone know what the metal is? Can it be welded by a skilled welder(not me).

Many thanks in anticipation... love the site.

 

[ChrisR]

The clue is in the question. T stands for Titanium. Yes really, that's what it is. Not the easiest job in the world but it is doable - to replace, that is, not repair. I took a T3 apart for salvage recently and have all the bits in the garden shed! You have to dismantle a lot of bits which should be corgi-only territory

It's an old boiler but engineered to last.

 

[ChrisLLLL]

Thanks for the info .... I will go for the replacement option....

Want to sell a heat exchanger from your garage bits ?

Or, if you can recommend a good source for a new one, it would be much appreciated.

Also, I have noticed drips from the Right Hand (red) expansion tank at > 1.5 BAR pressure.... is there a valve at the top that may be leaking, or does that whole tank need replacing (which I know is difficult).

Cheers

 

[ChrisR]

Can't remember if the valve's at the top or the bottom. But it should only leak AIR not water! Also can't remember if I kept the P vessel. You can put another one somewhere else on the system if yours is knackd, as long as you can stop the water leak.

I've just been told there were two different ones - not sure I believe that though! Ask Vaillant about that. HRPC list everything, pretty much, at http://www.partscenter.co.uk/hrpc/nav.html and look at MJT Controls where they seem to be 233+ vat. (061605) I can beat that easily for a new one. I'll look at mine for a part number.
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