Vaillant 400 series - combustible wall permitted?

[mogget]

Hi, a question for the RGI's. There are some corrosion issues with my Vaillant 418 which are safe for now, but will kill the boiler case eventually. This is caused by the boiler being fitted to a single skin exterior wall. Condensation is building up at the top rear case causing corrosion.

I plan to get a new Vaillant 418 fitted, and keep my existing one as a source of spares. I will not be fitting it myself.

The manual makes no reference to it, So I will ask, is it permitted for a Vaillant 418 to be fitted on a combustible wall? (Ie, a sheet of 18mm ply with Celotex / Kingspan insulation behind)? Just planning what the job might be next summer.

Thanks.

 

[mogget]

I think I may have answered my own question by searching the online PDF manual, but I would still like some perspective on the situation as to what considerations may be required.

 

[mogget]

I will ask my installer.

 

[Phill Peck]

Yes it can be installed like that?

Are you sure that's the cause of the condensation?

Is this something you've worked out for yourself or have you had an engineer to look at it?

 

[mogget]

(At the risk of getting a telling off)

It is something I have worked out for myself.

I shall be discussing it with an RGI and between us we will hopefully work out what the correct way of tackling the problem is.

 

[Phill Peck]

I'm not gonna tell u off but please take my advice

If the rust is appearing at the back behind the heat exchanger, get an engineer out ASAP.
There is a common fault with this range of boilers that could be your issue and would also result in POC's leaking
And could end up looking like this View media item 61853

 

[mogget]

If the rust is appearing at the back behind the heat exchanger, get an engineer out ASAP.
There is a common fault with this range of boilers that could be your issue and would also result in POC's leaking
And could end up looking like this View media item 61853

I will heed your advice, and yes that is what is happening. It's not as bad as that yet though.

I know where my competence runs out, and will call an RGI. I will isolate the boiler immediately (would prefer to keep warm, being cold is better than leaking POCs) and await your response.

Thankyou for the heads up,

Mogget

 

[mogget]

The pipe is now capped and the boiler scrap.

THANKYOU, Gasservice1985 for your very sound advice.

Mogget.

 

[Phill Peck]

The pipe is now capped and the boiler scrap.

THANKYOU, Gasservice1985 for your very sound advice.

Mogget.

Your scrapping the boiler?

It can be a fairly expensive repair but if there's not much damage to the casing worth repairing IMO

 

[mogget]

The casing behind the heat exchanger is so corroded it is nearly into holes. All the galvanising has gone, and it is as rusty as an old Talbot Horizon (I think I am beginning to show my age). I found a few other faullts in there as well. So I am taking the decision to have a new boiler fitted (straight swap) and keep the scrap one as a source of spare parts.

 

[Phill Peck]

Have you had an engineer out then?

I take it it looked similar to my picture then

 

[mogget]

Without wishing to say too much, the pipe has been capped and a tightness test performed. Given my lack of funds currently I feel this to be the safest solution, and my hunch about what you meant earlier was confirmed.

It wasn't quite as bad as the one in your pic, but the 418 was ageing and I have been thinking for certain other reasons, to get a new boiler fitted by an RGI. Like one who can notify it to building regs.

I think I have learnt an important lesson today (Mogget eats some humble pie).

Back to electric heating for now. Fortunately my living room is well insulated and I have an immersion heater.

 

[ScottishGasMan]

You cut it off yourself didn't you ?

 

[mogget]

Won't be doing any more. I've learnt my lesson.