Vaillant ecoMAX800/2 Condensing combi boiler

pengu · 18 Jun 2007

Hi,

I'm hoping you guy's can give a little advice. I've just moved into a house which has been stood empty for about 5mths. It has a Vaillant ecoMAX 800/2 combi boiler which was fitted in 2001, which has been fired up occasionally by the previous owner who now live in the IofM (uncontactable).
The problem is that there is no hot water and whilst the dials are showing 1/2 temp for both the water and rads, when the hot tap is opened the rads get hot, but the water is still cold.
I have learnt that the pressure should be running at between 1.0-1.5bar but it shows only a 0.8bar reading. I'm told that this is a simple task of filling the boiler...but how and will it solve the problem.??
Is there a valve which switches over the hot tap and the radiator...and could it be sticking....?
The system has a built in problem and diagnostic tester and it shows (5.14) that all the system is operating well...!!

gas4you · 18 Jun 2007

You can increase the system pressure by the built in filling link. Little taps under front right hand side as you look at boiler, about 3-4" back.

Its sounds like the dv is stuck in ch mode. When the hot tap is running you are getting S.14 which is burner ignited in hot water mode. You need to check d.35 when hot tap is running, it should read 1 (hot water dv position) if it does then it is a physical sticking of dv.

pengu · 18 Jun 2007

Dave..thanks for that,
I'm presuming the tap to increase the pressure is not the Pressure relief valve (coloured red). To be honest I'll check under the boiler tonight, for anything that vaugely looks similar to your description.
As for the DV, I guess that will need to be a replacement part and not a case of just getting it serviced...??

Cheers Ian

gas4you · 18 Jun 2007

No not the prv. The filling link taps are very small, about 1/2" black taps, on the end of about a 4mm tube.

It does sound as though you may need a new dv, but as I said you need to check wha the boiler thinks it is doing first

pengu · 18 Jun 2007

Cheers dave,

I'll check tonight and see if I can suss it.....I'm guessing the dv stands for diverting valve...or similar. Managed to download the Instructions for servicing manual, but it still shows no taps...anyway hopefully we can all get hot water tonight, those cold baths do nothing for me.

scatmanjohn · 18 Jun 2007

If you have got an ecomax the combustion door seal will need replacing.

I "think" vaillant are doing it free of charge so give them a call.

Make that your first job before anything else.

gas4you · 18 Jun 2007

scatmanjohn said:
If you have got an ecomax the combustion door seal will need replacing.

I "think" vaillant are doing it free of charge so give them a call.

Make that your first job before anything else.

Just the new ecotec plus range, made between feb 05 & mar 06. Vaillant will get in touch with customer direct, as long as installer was legit and registered it

scatmanjohn · 18 Jun 2007

gas4you said:
scatmanjohn said:

If you have got an ecomax the combustion door seal will need replacing.

I "think" vaillant are doing it free of charge so give them a call.

Make that your first job before anything else.

Click to expand...

Just the new ecotec plus range, made between feb 05 & mar 06. Vaillant will get in touch with customer direct, as long as installer was legit and registered it

Its not just the ecotec but the ecomax and ecomax pro.

gas4you · 18 Jun 2007

scatmanjohn said:
gas4you said:

scatmanjohn said:

If you have got an ecomax the combustion door seal will need replacing.

I "think" vaillant are doing it free of charge so give them a call.

Make that your first job before anything else.

Click to expand...

Just the new ecotec plus range, made between feb 05 & mar 06. Vaillant will get in touch with customer direct, as long as installer was legit and registered it

Click to expand...

Its not just the ecotec but the ecomax and ecomax pro.

http://www.vaillant.co.uk/Home/Products/Important_product_notice/ this link explains what boilers are affected. Its not just the seals it's the way the ecotec plus burns too hot and is set up that has caused some seals to go prematurely

scatmanjohn · 18 Jun 2007

From that link it seems that the are only admitting to the problem being on the ecotec.

Their tech help say something else.

Whether they are changing them for free on the ecomax is irrelevant because if it has the old style rubber seal it needs changing asap to a graphite seal and new nylon locking nuts.

Nearly every one i have come across has been knackered and have seen a few with the air inlet tube melted.

gas4you · 18 Jun 2007

At the end of the day most ecomaxs are now getting on a bit, so most should have had a new seal replaced at every service, graphite or not. The problem is that most service engineers don't bother

Ecotec Plus has the known problem of the co2 percentage increases by its self during the year and a 0.1% or 0.2% extra makes a lot of difference on these to the Kw output. Also the majority of the boilers with failed seals have not been range rated upon commissioning and left to run flat out when only really need 15Kw or so.

MI's should be taken with a pinch of salt on these as proper Vaillant engineers, not group service wa****s, will tell you not to set more than 8.8% CO2 case off at max

pengu · 19 Jun 2007

Morning lads....

Well I found the little black tap and sussed the pressure and am running it now at 1.25bar. This obviously has had no bearing on the hot water issue. I've arranged for a CH Engineer to visit this morning at some point and he reckons that for £45 he'll change the DV. Now whether that just means he's changing the diaphram or the whole unit, I'm not sure. Not too sure that I should bring up the CD seal as I'd hate to start ticking him off by suggesting what he should and shouldn't be checking, so may just see how he goes, what he suggests and take it from there. If he's good then I'll have him service it annually.
You two seem to have suqabbled a little over the CD seal, I didn't mean for it to go like that and would just like to thank you for your advice it's been invaluable. I know that is what this forum is all about, but I take nothing for granted and appreciate the help.

Big thanks Ian

gas4you · 19 Jun 2007

I wouldn't have called it a squabble, scat was only relating what Vaillant tech had told him and I have no problems with scat whatsoever

,
where as my info comes straight from one of the longest standing Vaillant engineers still around. I am just fortunate that usually I do not have to go through tech dept any more, as now they are group service the standard of service and info has dropped considerably

No diaphragm. I would think he means £45 labour plus parts. Although due to the size of these boilers they are easy to work on. If the seal has been replaced there should be a sticker with the date on, on the front of the burner assembly, if it was done correctly

If it is there don't let him open it, as even the new graphite seals have to be replaced once they are disturbed, even though the give them a 5 year life if left alone

scatmanjohn · 19 Jun 2007

I wouldn't have called it a squabble

Me niether

pengu · 19 Jun 2007

Well I'm pleased that it all worked out fine.....just one query though. Presuming this guy who is calling in about 30mins is useless (hopefully not) are any of these Vaillant engineers you know local to the West Yorkshire area of England and could either of you guy's recommend one..??

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Vaillant ecoMAX800/2 Condensing combi boiler

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