Vaillant Ecotec 831 problems

[JSHarris]

Thats got to be a wind up surely?

The cause of your problems are:
1. Bad installation, dirt in the system, inadequate flushing and/or lack of correct inhibitor. 80% of F.75s are related to carp in the boiler as are leaking DV spindles. There are other issues, but lack of correct servicing and dirty systems are top of the small list. I bet the DV isn't leaking clean water right???
2. Incorrectly diagnosed problems by visiting engineers.

If you had these problems within the 2 year warranty, then a call to Vaillant would have seen you with the upgrade kit fitted and advise on the water quality (if needed).

Possibly the DV is partially seized and staying in the Heating position and causing the rads to warm when the boiler is doing warmstart (pre-heat). Turn off the warmstart to confirm this. If and when the boiler 'stays on' press the i button instead of turning it on and off. There is no case that the heating would be on or the pump running and S.0 or S.30 are displayed.

Not a "wind up" as you put it, at all. First, the warranty was for one year, not two. Second, the installers came out around a dozen times in that first year to try and fix, or in the case of the leaking hoses fix, the boiler during the warranty period, then said they had to charge for the call outs over the following year (perhaps another dozen or so). As it was clear that the installers couldn't resolve the problem, I had another firm out to look at it, but they were every bit as stumped.

I've had several assurances that dirt in the system isn't the cause. The original installers flushed the system for a couple of hours or so, using a large tank on the floor with filters and a magnetic trap, before they installed the boiler. They also installed a filter on the return pipe just under the boiler, made by a firm called Magnaclean. The last repair to the boiler was the replacement of the diverter valve last year, and when this was replaced the engineer commented that the boiler was clean inside and that he didn't believe that the long-standing F.75 problem was caused by dirt. The boiler has been serviced each year, and kept topped up with inhibitor.

The diverter valve did develop a leak around the shaft, dripping what looked like clean, but rather smelly, water on to the worksurface under the boiler. I have the old one (the engineer left it behind when he replaced it) and it looks clean inside and was still working when it was replace, it just leaked. As far as I can tell the new diverter valve is working properly, as even when the boiler gets stuck with the heating on (with no demand from the room 'stat/programmer) it still switches over from heating to hot water mode as normal.

According to the diagnostic display, there is no call for heat (it shows either S.0 or S.30 when it's not in anti-cycling mode or pump over-run mode) yet the boiler will still run in heating mode with normal burner and temperature control as far as I can tell, unless I turn the temperature dial to zero to shut it off, or go through the ritual of turning off the power, waiting, and then turning it back on. Even with the programmer/'stat disconnected the boiler continues to run as if it were being called, which to me seems to indicate an internal fault condition of some sort.

[edited to add:] Sorry, I just noticed your mention of an "upgrade kit". Is this the replacement of the pressure sensor and pump? If so, then that was done under warranty, I believe at the direction of Vaillant.

 

[JSHarris]

I would treat yourself to a vrc 430 or 470 after the engineers visit...

Ebus controls from vaillant and their boilers are a fit for purpose match, and with over 50 boilers out there with this match, it is noticable that these controls reduce sognificantly issues...

I tend to agree, this is a good boiler and worth keeping..with vaillants controls you wont be buying a better boiler...that match is the end of the product line and you wont be nuying a better boiler...

Thanks, I did consider the Ebus control option, but decided to retain the simpler control that we already had. With hindsight, now that we've improved the house insulation, I should have really opted for a weather compensating control system, as we don't really need high flow temperatures during milder spells, only when it gets particularly cold for a few days.

 

[ALEC1]

What people overlook is that all boilers have to accept compensation controls if the boilers are sold in Germany all boilers have had to use an outdoor sensor since about 1985..

I only install boilers with this technology and not only do they produce better heating systems, they enhance reliability and fuel efficency..

 

[The831Bunny]

All 831 ecoTECs have two years manufacturers warranty. Only the Pro 24 and 28 have 12 months. If Group Service would have attended during your two year warranty period they would have replaced the hoses with the copper tubes which relocates the pressure sensor to the amended position. This 100% eliminates F.75 problems where pump, expansion vessel and system resistance have been checked to be OK. It beats me why you never called Vaillant, but insisted you get people back who have never fixed it, and continue to charge you. Hence, wind up!

Why do you think the heating is running when the boiler is displaying S.30? Pump on, pump off, fan on, fan off, burner on, burner off???

 

[JSHarris]

What people overlook is that all boilers have to accept compensation controls if the boilers are sold in Germany all boilers have had to use an outdoor sensor since about 1985..

I only install boilers with this technology and not only do they produce better heating systems, they enhance reliability and fuel efficency..

Knowing what I know now, I'd have to agree 100%, and wish I'd understood this back when we had the boiler installed. I'll admit to be sceptical at first (hence the retention of the simple programmer/'stat) but with all the added insulation to the house and the improved airtightness we do really need weather compensation now. In practice I do this crudely and manually, by increasing the boiler flow temperature when it gets particularly cold and reducing it when it's mild, but it would be much less nuisance to have this done accurately and automatically.

 

[JSHarris]

All 831 ecoTECs have two years manufacturers warranty. Only the Pro 24 and 28 have 12 months. If Group Service would have attended during your two year warranty period they would have replaced the hoses with the copper tubes which relocates the pressure sensor to the amended position. This 100% eliminates F.75 problems where pump, expansion vessel and system resistance have been checked to be OK. It beats me why you never called Vaillant, but insisted you get people back who have never fixed it, and continue to charge you. Hence, wind up!

Why do you think the heating is running when the boiler is displaying S.30? Pump on, pump off, fan on, fan off, burner on, burner off???

I've just double checked the paperwork and the boiler was installed in September 2008, and definitely came with a 12 month guarantee, not two years, I'm afraid.

I'm not sure what you mean by copper tubes, as my boiler still has two rubber hoses at the back (the ones that originally developed leaks). I do know that the pressure sensor was replaced, several times, but I don't think it was moved. Looking at it, the pressure sensor is at the bottom of the boiler, to the left, behind the fold down box that contains the electronic controls. This seems to be the correct place for it, according to the manuals that I have.

As I said before, Vaillant have been involved, as the original installer contacted them for advice, more than once I believe. I always dealt with just the original installer at first, then another company a year or so after the guarantee had run out.

I've now written to Vaillant (following the good advice given earlier in this thread) in the hope that talking directly to them might shed some light on the ongoing problems, but previously I'd relied on the knowledge of the engineers who have called (and although I've only dealt with two firms,the original installers sent several different people around to look at it).

The latest problem (the boiler staying on in heating mode) was the reason for me asking advice here, and is the one that has brought matters to a head for me. Although a complete amateur I'd worked out that the new intermittent fault may be with the circuit board, given the limited testing I've been able to do which showed contradictory indications (like no call for heat but the boiler still firing). I was hoping for confirmation of this from here before calling in the engineers again, and some of the other advice earlier in this thread seems to confirm my suspicion.

Clearly replacing the circuit board is going to be costly, and added with the history of poor reliability I've experienced I'd seriously been thinking that yet another expensive repair would be throwing more good money after bad. The consensus here seems to be that this is basically a good boiler, so I have to assume that I've just been unlucky. This is somewhat reassuring as it means that having the circuit board repair might then make sense, rather than paying out a lot more to replace the whole boiler again. If Vaillant can provide me directly with advice on fixing the the long standing F.75 fault as well, and if the boiler is then reliable enough to run through the coming winter without failing to fire on cold mornings, I shall be delighted.

 

[The831Bunny]

Lets try angain...Copied and pasted from the 2005 users instructions:

Instructions for use ecoTEC

3 Instructions on operation

3.1 Factory guarantee

3.1.1 Two 2 year guarantee for ecoTEC plus appli-ances Vaillant undertakes to rectify any manufacturing defect that occurs within twenty-four months of the installation date. For the 2nd year of the guarantee to be valid an annual service must be carried out by a CORGI registered instal-ler one year after installation. The cost of this annual service is not included in the guarantee.

My best and only advise is to contact Vaillant for a fixed price repair. You will get the rubber pipes changed to the copper kit which relocates the pressure sensor, the heating problem sorted out and probably the combustion chamber seal changed. Pound to a penny that's not been changed either... the main advantage you will get is something you have seriously under estimated so far.. KNOWLEDGE!

 

[JSHarris]

Lets try angain...Copied and pasted from the 2005 users instructions:

Instructions for use ecoTEC

3 Instructions on operation

3.1 Factory guarantee

3.1.1 Two 2 year guarantee for ecoTEC plus appli-ances Vaillant undertakes to rectify any manufacturing defect that occurs within twenty-four months of the installation date. For the 2nd year of the guarantee to be valid an annual service must be carried out by a CORGI registered instal-ler one year after installation. The cost of this annual service is not included in the guarantee.

My best and only advise is to contact Vaillant for a fixed price repair. You will get the rubber pipes changed to the copper kit which relocates the pressure sensor, the heating problem sorted out and probably the combustion chamber seal changed. Pound to a penny that's not been changed either... the main advantage you will get is something you have seriously under estimated so far.. KNOWLEDGE!

Thanks, that conflicts with the paperwork I have, though. The installer has clearly said in the quote I have that the guarantee is for 12 months, with an option (that I foolishly didn't take up at the time) of extending this guarantee to four years for an extra sum. As you rightly say, knowledge is key, but as a consumer I expected the installer (a fairly big firm) to have whatever knowledge was needed to fit and repair the boiler. Perhaps I was too trusting, but they did give every indication at the time that they were doing everything possible to resolve the problems. I recall at least one of the engineers saying that problems with Vaillant boilers were unusual, which is the advice I'd been given separately when looking around for a replacement in the first place.

The original installer started charging me for call outs and repairs after the 12 month period, and I found they were fairly expensive (typically around £150 to £250 per call out). I only ever called them out (after the warranty period) to try and fix the ongoing F.75 problem (which only occurs in winter). The leaking diverter valve was replaced by another firm, who I also got to look at the ongoing F.75 problem (and do last years service).

Thanks for the advice about the "copper kit". As this seems to be to rectify a design fault, I wonder why it wasn't fitted when the apparently defective original pressure sensor and pump were replaced? If this were a car then one would assume that the manufacturer would do a recall and retrofit replacement parts for defects like this. It makes me wonder why the original installer didn't find this out when talking to Vaillant, unless this is something that has arisen since then.

I have written to Vaillant for advice, but was unaware that they would deal directly with customers in the provision of repairs. Up until now I'd assumed that they only dealt with installers and heating engineers, so thanks for that advice.

It is a bit galling to have been living with this thing for four years, to have engaged the services of apparently professional heating engineers and yet to find that they seemingly lacked the competence needed to resolve these ongoing problems. It says something when you seemingly cant trust professionals and get better advice from an internet forum! Many thanks.

 

[Phill Peck]

It sounds as though the installer gave u a 12 month warranty. And didn't register it with Vaillant.
These boilers now have a 5 year warranty.

As said contact Vaillant and you will get get an engineer who knows he boiler inside out and will sort the issue.

Next you need to get the system clean. Was it flushed in installation?
I would suggest a chemical flush and a filter such as spirotec mb3 to protect te boiler.

As I said mine is 7+ year old and not had a major issue. This is probably down to it being a new system not a new boiler on old pipework and rads. There is no sludge or dirt in my system. And I know this for a fact as I drained the system and moved the boiler from kitchen to loft this summer, connected it all up tured it on and not a problem

 

[Phill Peck]

Thanks for the advice about the "copper kit". As this seems to be to rectify a design fault, I wonder why it wasn't fitted when the apparently defective original pressure sensor and pump were replaced?


If Vaillant had attended thy would have done.
I'm not sure when then kit was realeased 831 bunny might know. I think he kit has been out quite a while though

 

[JSHarris]

Thanks again. I'm sure you're right, the guarantee I have seems to be from the installer, not Vaillant themselves.

The system was flushed for a couple of hours before the boiler was installed (as I mentioned at the top of this page), and it has a filter fitted underneath it, on the return pipe (a Magnaclean). Both of these were conditions of the installation from the installer, along with fitting TRVs on all the radiators.

I really wish I'd not been so trusting with both the original installer and the second firm now; with hindsight I should have contacted Vaillant directly when the problem first occurred, it seems. The trouble was that the chaps from the first installer were genuinely helpful, plus they did a very neat job. It was easy to trust them to do the "right" thing, given the effort they seemed to make to try and get to the bottom of the problem.

I've now written to Vaillant, as mentioned above, so will keep my fingers crossed that I can get the problems resolved without too big a bill.

 

[ALEC1]

Installers are only as good as the information given to them, and an easy scape goat for all the ills of the industry..Manufacturers have been muscling into installers natural territory (maintenance and repair) for years now..


Magnacleans can be problematic if not cleaned regularly, and this would contribute to the failure of the hoses...

Interestingly the lower temperatures and the longer running pump times seems to reduce significantly the occurence of hose failure...

 

[JSHarris]

Installers are only as good as the information given to them, and an easy scape goat for all the ills of the industry..Manufacturers have been muscling into installers natural territory (maintenance and repair) for years now..


Magnacleans can be problematic if not cleaned regularly, and this would contribute to the failure of the hoses...

Interestingly the lower temperatures and the longer running pump times seems to reduce significantly the occurence of hose failure...

I'm sure you're right, I did feel sorry for the guys who were trying to fix it, as it was getting to the point where they were a bit embarrassed about the problem every time they called around. I'm sure that if they'd been given the right information they would have fixed it, and I can't help but wonder why they weren't.

The filter has been cleaned annually, when the boiler has been serviced, but the hoses started leaking just a few weeks after the boiler (and filter) was installed. When the engineer fixed this he told me at the time that the factory fitted hose clamps were all loose. He fitted new clamps to the hoses and all has been well with them since then.

As the system was flushed and has remained clean, as far as I can tell from things like leaks, and as I've been told by those who've worked on it, I'm not sure how the filter could have contributed to the problem in this particular case. I've only once seen the inside of the filter when it was being serviced, and it did seem to have a black coating on the filter element, so perhaps the system isn't as clean as has been reported. However, the water that leaked out last year, when the diverter valve shaft seal failed, seemed fairly clear and left just a very slight faint brown tinge on the sheets of kitchen roll I placed under the boiler to soak up the drips. It did smell fairly horrible, a sort of faintly acidic smell, but I don't know if that's an indicator of a problem or not.

Good to know about the low temperatures and longer run times being good for the hoses!

 

[Steelmasons]

Hi,

We had an Ecotec 831 installed around 4 years ago, to replace an ancient wall mounted boiler. The improvement in efficiency (and much reduced gas bill) was welcome, but the thing has been very unreliable, with the dreaded F75 fault being a very regular occurrence each winter, and seemingly unfixable by those who've tried - all the engineers who've looked at it have said that sometimes these boilers just do this.

The boiler developed leaks from the rubber hoses shortly after installation (fixed under warranty by fitting new hose clips), the diverter valve started leaking a year ago and was replaced (the shaft seal had failed) and now the boiler has developed another fault that keeps the heating on all the time.

At this point I'm wondering whether to call the engineer in yet again, or scrap the boiler and get something that will work reliably (absolutely not another one from Vaillant!), as I get the feeling I'm now throwing good money after bad.

The symptoms of the latest fault are that, usually after a power interruption (we get occasional power cuts here), the boiler will get stuck into running the central heating all the time, even if the room programmable thermostat is physically disconnected (I can unplug it from the wall). The hot water still operates normally, with the boiler switching between heating and hot water as normal, the boiler displays no fault codes and the information display confirms that there is no heating demand from the room thermostat.

Even with no heating demand from the room thermostat the boiler keeps running the heating, unless I turn the heating flow temperature dial to zero
!

So 11 odd months later you still have this problem? (a new thread you have started)

831 suggested to you that this thread is a wind up , much like the other thread too.

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