Vaillant eco-max pro

[petercj]

Have a Vaillant eco-max pro boiler which was running sweet until some work was done on the system (not re the boiler) which involved the system being drained and refilled - a couple of months back.

Since the water was changed, the boiler has been very noisy in the first half of the heat-up cycle.

Pretty sure its not air, because the system has been bled a number of times, and this noise remains some weeks after the system was drained/refilled. Anti corrosion and anti-noise additives have been put in, but to no obvious effect.

The recovery time is good, and apart from the noise, everything seems to be working OK.

The noise starts shortly after the boiler fires up, and gradually gets worse until the temperature gets to mid 40's c, at which point the noise dies away and boiler will run on for the rest of the cycle up to 60c very quietly.

As the noise approaches its peak it sounds as if the case is vibrating, but there seems little in the way of actual vibration when the case is touched. Despite the racket, the boiler hasn't cut out, or paused.

Any thoughts?

 

[Rickster123]

Why was the system drained? Did you have extra radiator fitted?

 

[diamondgas]

Could have dislodged something or other that's ended up in the filter or heatex? Could do with checking temp diff across f&r to see if there's a restriction through hex ... other possibility is a noisy burner disipating when the boiler modulates down!

 

[jtsplumbing]

Are you in a hard water area ??

 

[petercj]

Thanks for your replies.

This problem of noise with the boiler started after a new hot-water cylinder was fitted by BG.

The differentials between F & R are pretty good, i.e. 20% for at least 50% of the cycle.

There was something metallic bouncing around in the return pipe after the tank was fitted, which to me sounded very much like a ball of solder or maybe a sliver of copper. The recovery time on the replaced cylinder was poor, and so it has been replaced, and the recovery time is now very good. My concern is that something has been transferred from the faulty cylinder into the system, and that whatever it might be has ended up in the heat exchanger. Is that possible, or is there a filter to prevent that happening?

BG have put the noise down to air in the system up until this week, now they say it's down to magnetite in the system.

Whatever the problem is, it's happened following the fitting of the first faulty cylinder.

The boiler had its annual inspection by BG about a month before this problem arose, and was seen to be fine - which it was, it was running as sweet as could be - hardly a whisper from it.

The issue now of course is that if the problem is put down to magnetite, then it's not covered by my BG Homecare contract.

The boiler is 5 years old, and the system was power flushed before it was fitted. BG didn't supply and fit the boiler, but its been under their HC contract throughout it's life.

If magnetite was washed into the heat exchanger when it was refilled, do you think it could cause this problem?

If it's something that was transferred from the first replacement cylinder, how the heck do I prove it? In fact, how the hell would I get it out?

 

[petercj]

Any more thoughts based on the further info?

Thanks for any help offered.

 

[Rickster123]

I would get bg back in to rectify the fault. If it has only just started since they carried out work then it's down to the. To sort it.

 

[petercj]

I would get bg back in to rectify the fault. If it has only just started since they carried out work then it's down to the. To sort it.

If only life were that simple APP!

The BG adverts say: "Looking after your world", but in my experience the reality is very different.

Last weeks visit was the tenth by BG, and so far twelve different members of BG staff have visited.

The latest suggestion by BG is that the system needs power flushing - which is chargeable and not covered by the Home Care contract.

To recap: the boiler is approx 5 years old, and the system was power flushed when it was fitted (not by BG).

The boiler and system has been under BG HC contract throughout its life.

Prior to the current problems, the system has only been previously opened once within the last 5 years, and that was by BG when they replaced some TRV's under the HC contract.

The assessment made by the (experienced) BG engineer at the last visit was that the system has been taking in air through a small amount of Speed Fit that was used in the extension - most of the system is in copper, but about ten metres is in SF - all of the SF is stamped with: "British Standard kite mark: Part 3 - 1990"

Whenever there has been a problem with just about anything to do with the central heating, BG have picked up on this small amount of plastic pipe work. I rang the manufacturer's when BG first told me that the pipe sucks air, and they said that some time back some engineers fitted the wrong pipe (not made for hot systems) and this earlier misuse of the product is often confused by engineers when coming across the correctly installed pipework.

The radiators are a mix of older (30 yrs old), and newer rads (10 yrs) - the BG engineer took a water sample by loosening a TRV valve on one of the older downstairs rads. Not surprisingly after 5 years, the water contained some magnetite. However, all of the rads have a good distribution of heat top to bottom. BG have said they are sending this water sample for analysis to support their assessment re the noisy boiler - which was running ABSOLUTELY fine until the work was done by BG.

Vaillant are coming to look at the boiler tomorrow - but based on what I have read on this forum, the chances of me getting a detailed report as the BG customer are pretty slim.

If Vaillant put the problem down to some kind of restriction in the heat exchanger, the issue under contention will be over what has caused it, and who is responsible for the cost of rectifying it.

To my way of thinking, if the bore of the heat exchanger had become restricted through a build up of scale/marnetite over a period of time, the boiler would have gradually grown noisy, not gone from being virtually silent to sounding like a bag of nails over night, and coincidentally after BG had worked on the system?

But, I'm not a heating engineer, so could I be mistaken in such reasoning?

The other question I would appreciate a view on, is whether power flushing would be likely to clear a blocked heat exchanger of the type fitted in this boiler, i.e. basically being a coil of small bore ss pipe?

If power flushing is likely to fix this problem, then I won't be paying BG the £600 or so they charge - I will hire a machine and do it myself.

If the heat exchanger is US, then I'll probably write the boiler off and fit a boiler more suitable for hard water areas.

When I came to this property it had a boiler that was only three years old, but hadn't been installed properly, and BG told me that the heat exchanger would be restricted due to scaling, and that the boiler was a write-off. Hence the installation of the Vaillant. Which makes me wonder whether such heat exchangers can be successfully descaled and opened up again?

If one of you guys can give some advice, it will be very much appreciated.

 

[moogwai]

It does sound its debris in the heat ex. If i were you i would get a gsr to remove the heat ex and just solely flush this out first to make sure this is clean and free from debris then see how it goes. At least then you'll know one way or another and itll be cheaper than replacing the boiler and the power flush.

Sent from my GT-I9100 using Tapatalk 2

 

[moogwai]

If the system has been topped up yearly with inhibitor lime scale shouldnt be a problem.

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[petercj]

Thanks moogwai

Would you expect Vaillant's staff engineer to test the flow through the heat exchanger with a flow-meter, or something similar? I mentioned this to one of the BG engineers, and he looked at me as if I was: "one of those customers!" :thinking:

I have wondered whether the boiler could be disconnected from the system and have some kind of aggressive solvent pumped through it. Presumably this is a pretty common problem.

Any ideas on a ball-park figure for such work?

 

[petercj]

If the system has been topped up yearly with inhibitor lime scale shouldnt be a problem.

Sent from my GT-I9100 using Tapatalk 2

Apparently: "Looking after your world" doesn't involve checking on inhibitor levels as part of the BG Home Care annual inspection (which they refer to as: "a Service").

You get a gas check, a visual check of the more obvious pipe-work, and that's about it. The front cover on the boiler never gets removed.

If you question the BG definition of: "a Service", you get that funny look again! :thinking:

 

[moogwai]

Thanks moogwai

Would you expect Vaillant's staff engineer to test the flow through the heat exchanger with a flow-meter, or something similar? I mentioned this to one of the BG engineers, and he looked at me as if I was: "one of those customers!" :thinking:

I have wondered whether the boiler could be disconnected from the system and have some kind of aggressive solvent pumped through it. Presumably this is a pretty common problem.

Any ideas on a ball-park figure for such work?

I think the vaillant engineer will say " there is debris in heat ex due to a dirty system, and because the system is dirty its not our problem" which will put you back to square one. It would probably take a qualified engineer 3 to 4 hours to do as the boiler will have to be stripped down almost completly and you should be prepared to spend around 150 to 200 for this maybe a bit more. Its definately not a job for an unqualified engineer.

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[moogwai]

Just looked on ebay and a new heat ex is around 220 if found to be blocked up.

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[moogwai]

Or get a heating engineer to drain down the system cut into the flow and return and hook these upto a powerflush machine and clean just the boiler out with fernox ds40. Heh heh....only just thought of this and it would be the easiest way of cleaning the heat ex.

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[petercj]

Thanks again.

My guess was that it would be at least £500, and then there might be other components showing wear after 5 years, thus adding to the cost.

I would think long and hard about spending £500+ on a 5 year-old condensing boiler. From what I've heard, 10 years is around a realistic life expectancy - wonder what you think re that?

With the wisdom of hindsight, I've been thinking that a Worcester-Bosch might have been a better bet in a hard water area? I believe they use a matrix construction with bigger water ways - or at least some of their models do.

Making a heat exchanger from a coil of small bore pipe probably has a big cost advantage from a manufacturing point of view, but to my way of thinking, it's bound to be prone to becoming restricted in a hard water area. While such a coil may be cheaper to manufacture, Vaillant certainly don't reflect such a saving in what they charge for them.

BTW, I do have a background in engineering myself, but I would never attempt such a job on a gas appliance.

Oh well, I'll let you know what the Vaillant inspection comes up with.

Even if they won't give me much of an opinion on the 'ins and outs', I will be watching to see what goes on.

Depending on what they say, I'll think about which way to go - which might involve dropping a line and some photographs of the work done by BG to BBC Watchdog.

Keep an eye on the program - you might see Ann Robinson giving the: "Looking after your World" slogan an airing!

Thanks again for your input.

 

[GrahamM]

Firstly, you say system was powerfushed before fitting current boiler. How good or bad this was done is impossible to tell at this stage.
It is likely the system was still quite dirty and unless system was dossed with the proper chemical ie. inhibitor and replaced after any drain downs it is possible the system is now becoming quite clogged up at this stage.

I doubt you will get anywhere with BG if your system issues are due to magnetite/sludge in the system.

Your cylinder was already replaced due to circulations issues and as the system was drained to facilitate this it sounds like it has made a bad problem worse.

In my opinion BG are not directly to blame for this and you may need to bite the bullet and get a full flush done by a reputable company/person. Make sure properly dossed with chemicals etc.

 

[petercj]

I suggest you get the facts right before airing your opinion GrahamM

As I have already said on this message board, the boiler was running perfectly, almost silently, until BG replaced a leaking hot water cylinder.

Just to be clear on this point, the cylinder sprang a leak, there was no particular problem with the recovery time.

The new tank fitted by BG had a recovery problem, i.e. nearly an hour when all the calculations and the tank manufacturer's data indicated it should have been between 20 to 30 minutes.

In order to meet British Standards, the cylinder involved should have recovered from a 70% draw off within 30 minutes - more info here if you need to appraise yourself of such standards.

Welcome to Telford Copper Cylinders

After the fitting of this cylinder the boiler developed the noise in question.

A metallic noise was heard coming from the 22 m return - a few metres from the boiler. Which went off after 24 hours or so.

The faulty cylinder was replaced, and the recovery time is now good.

However, the boiler noise remains. All of this information has already been posted by me.

One of my questions has been whether anyone can explain why the boiler could go from running quietly to very noisily within a period of one day - that day being the day BG worked on the system.

If you have an explanation for this, I would be glad to hear it?

If deposits of scale were dislodged when BG broke into the system, and they have caused a restriction in the system, then that could be one explanation.

Another could be that something untoward has been transferred from the faulty cylinder into the system, which has entered into the heat exchanger and caused a restriction. The coil in the faulty tank had a 6.1 m surface area coil, so something must have been very wrong for it to take nearly an hour to recover. BG did the gas input calculations, and considerably more kw’s were being inputted to the cylinder coil than the manufacturer’s specifications for a 20 minute recovery.

I do have various bits of pipe-work recently removed from the system, one piece being from the Return when the Magna Booster was fitted. Clean as a whistle. I also have a gate valve removed from the area of the cylinder, again clean as a whistle.

If the heat exchanger is cited as being restricted, then I probably will have the boiler replaced. Once the boiler is removed (not by me) I will cut the heat exchanger up and verify what the problem is.

[FONT=&amp]Depending on what is found, I might then make a claim against BG – through the County Court if necessary.

BTW, BG did a check on the water before taking the system on contract. As I have said, prior to the recent intervention, they are the only ones to have opened up the system in the last 5 years.

Having paid around £25 per month to BG throughout the life of this boiler to look after it (I can look after the rest of my world) I expect them to take responsibility and step up to the plate and do the right thing.

Let BG provide the evidence, and then I'll see how I can best use it.
[/FONT]

 

[GrahamM]

Put your teddies back in pram.
You have now furnished us with more pertinent info that was not given before.
Good luck or not!

 

[jtsplumbing]

If a replacement EX is around £220 on ebay, would Vaillant not replace this on there fix'd price repair ?? or do they not cover the EX ??