Green star 24i no pressure

(A wee bit of wee escaped... )

 

Hi Richard.

Well, it does seem to clearly indicate that the fault - leak - is within your boiler (assuming your shut-off valves did shut-off fully...)

And, if the sound of the loss can be heard through the condensate pipe, then the leak is almost certainly within the combustion chamber.

Which all suggests a leaking exchanger, I believe.

Why it should happen more at some times and not others, I haven't a scooby. Perhaps the expansion of the part due to heat affects the leak. I dunno...

 

Sounds like the heat exchanger then. When your boiler is running the expansion will close the crack keeping the boiler at holding pressure,as the boiler returns to a cold state the crack will slowly open.
Answering your last question the PRV is mechanical and opens under pressure, no electrical issues will cause pressure loss.
Time to get the engineer out and throw your findings at him(I don't mean take the boiler off the wall and chuck it at him).
Good luck Richard..

 

Richard, how old is this Worcester?

If p-boy is right with his diagnosis, then you can expect a large bill, I'm afraid - unless you can arrange a fixed-fee repair.

There is the separate issue of whether the additional exp vessel was ever needed, and how your plumber diagnosed this as the 'fault'.

I mean, if it turns out that YOU have correctly diagnosed the true fault with the help of a DIYer on an internet forum, when these guys patently failed to do the same when standing in front of the darned machine, and landed you with a sizeable bill for good measure, then I think you have the right to feel a touch peeved.

And if it is a leaking exchanger, you can feel quite justified in telling them they can refund the exp vessel bill.

And, and, if this boiler is less than, say, 6 years old (possibly more), then I believe you can successfully sue Worcester for the replacement of the exchanger; a quality boiler should simply not develop such a fault in that time. You can argue that your boiler must have been inherently faulty (sub-standard weld, for example) from new.

People who have the balls to tackle companies on such issues usually find that they win. As they rightly should.

(I got Panasonic to pay for an exploding PSU section of an out-of guarantee tele, on the simple basis that it just should not happen to a 3-year old TV of Panasonic's reputed quality).

 

"Then a week or so after it developed this fault. I phoned the engineer and explained that there was water outside which I thought was coming from the overflow"

Is the condensate pipe anywhere near the bathroom overflow pipe?



"he said it was the expansion vessel was gone and that he assumed was the problem and he would replace it as this was a common fault with the combi and he always carried a spare in his van."

What? He carried out no tests of his own?! Surely he did? I mean, even if it had been the safety discharge pipe that had been dribbling which would have pointed to the exp vessel, the chances are it just needed recharging rather than replacing. This is determined by a simple and quick test - surely he did that?

If not, ohmygawd. (How much did this new exp vessel cost?)



Of course, it might be that the exp vessel was terminally faulty, and he did test it before fitting the extension one. And it might be that when the vessel went faulty and caused the PRV to dump the excess water, this increase in pressure triggered the exchanger's leak (tho' - at only 3 bar - it shouldn't have...)

BUT, if water never came out the safety pipe, then the exp vessel was not faulty, and the guy jumped to a silly, untested conclusion that's already cost you money. And has not fixed the fault!

Ok, important question - you are obviously very familiar with the pressure gauge on your boiler and what it's reading. From when all this 'losing pressure' malarkey started, have you ever seen the pressure rise significantly to well over 2 bar?


In any case, with the young age of your boiler and the regular servicing (approved W-B agent, by any chance?) I would expect Worcester to cover the cost of a replacement exchanger. They might initially say 'Non', but I would make it clear to them that they will end up paying, either from goodwill or else via SmallClaims County Court or MoneyClaim.gov.

I have very, very, very little doubt whatsoever that you would win this.

 

.....



(I'm speechless)


(Need to dash, but will reply later. Meanwhile, I'd love to hear what plumbers on here think of this guy's diagnosis technique... )

 

Your speechless, I'm shocked,no testing of any form.
That is not the service of a good heating engineer,he's carrying out repairs by lottery chances.

CRAZY,CRAZY,CRAZY.

 

Thanks, plumb-boy. So it's not as tho' I've something obvious here - phew.

And the really bizarre thing is that exp vessels commonly lose pressure so need topping up (a 10-minute job) but much rarely actually fail and need replacing. So why this guy felt like jumping straight in with a replacement, gawd knows.

The good news is that he charged a very reasonable price...

(If you feel like it, Richard, you could test your existing vessel very easily and, if it's working fine, get every penny back off that plumber (let us know if you'd like to know how - it'll take a minute...). I would certainly not have him in the house again, trying to figure out what's wrong...)

Ok, Richard, you have two separate issues here. The first is your current plumber's work, and whether it was actually needed - did he make a foolish, knee-jerk decision?

The second issue is the leak.

To answer your specific Q; as long as the boiler shows a pressure over - ooh - about 0.7bar and is running fine, then no harm in running your hot water. I cannot explain, tho', why it isn't losing pressure with only the hot water being used; in theory the same main exchanger is being heated when drawing hot water as it is with the CH on. So I'm stumped there.

How to claim off Worcester? First you need to have the fault - leak - properly diagnosed by someone who knows what they are doing... I guess, ideally, it'll help if it's a W-B approved guy, 'cos you'll likely be getting him to do the actual replacement when it comes to it.

So, you need to find the 'guy'. I don't know if the W-B site has a list of approved installers/repairers? You get this guy out, he carries out the proper checks, he diagnosis a leaking exchanger, and he gives you a quote (gulp - around £400+?). You say "Thanks, you will be doing the work, but I'm going to tackle W-B to cover the payment first, as a main exchanger in a high-quality, fully-serviced boiler should not fail in 6-years. So I'll be in touch in around a week to give you the go-ahead."

You contact W-B's customer service by email (so you have a copy and you know they've received it) outlining the situation. You are polite but insistent. You tell them you chose the boiler for it's supposed reputation for quality and reliability and had it serviced every year - attach a scan of the document. Then explain your disappointment at discovering that a major component - which should last for decades - has failed in 6 years, and that you therefore conclude it must have had a fault or weakness from new - it is not of satisfactory quality. Also attach the repair quote. Explain you'll be using a W-B approved engineer, and that you expect W-B to approve the repair and offer to cover the full cost. Make it clear that is what they should feel obliged to do without any further word from you, and you look forward to receiving this confirmation by the Xth (give them, ooh, 4 days). Finish by saying that you will be giving the repair the go-ahead on that date in any case, and if they don't agree to cover the cost, you will instead sue them using moneyclaim on-line (www.moneyclaim.gov.uk/web/mcol/welcome) which is like a web-based county court small claims service. Make it clear you will win this claim regardless, but if they put you to the trouble of having to go through this process, you will be hugely annoyed by their dereliction of their responsibilities and you will highlight their shocking customer service very loudly on the UK's No 1 trade and DIY forum..."

Ooh, I'm shaking at this threat...

Ok, back to issue one... Do you know how to locate the exp vessel inside your boiler? If so, you should find a car-tyre valve (shrader?) on it. Remove the safety cap and take a pressure reading using a car/bike tyre pressure gauge.

Then try pressing the wee pin in t'middle. You should expect what you'd get from a tyre - a release of air (tho' not as dramatic as a car's).

Report back on whether this has happened. You are also looking our for water spluttering out - that would be a bad sign, and indicate it's knack'd.

 

I'm guessing the wee exp vess on the inlet is one of them anti-hammer thingies I've heard about.

Good move - sounds very positive.

Absolutely gob-smacked about the boiler's exp vessel - why on earthy didn't the guy test this?

I have seen that W-B offer these 7-year warranties on new installs with certain provisos - obviously that a certified W-B fitter is used, the system is power-flushed, filter fitted, annual services with them, etc etc. So don't be too surprised if they try and crawl out of it if you don't tick all of these boxes. HOWEVER, if they try, it is not the end of the game. It will come down to what is reasonable. And a blown exchanger in 6-years chust ain't. So be confident you do have a valid claim either way.

(Are you just going to ignore the first guy...?!)

 

No idea - I don't even know what you are saying...

Which 'discharge hose' - the safety release pipe (15mm copper) from the PRV, or the condensate pipe (22mm plastic)?

And what do you mean that it 'refills itself'?

By isolated, you mean he's shut off the flow and return from the boiler so the boiler is isolated?

Anyways, what's the guy himself saying is the fault?

(And while he's there, can you mention the exp vessel situation to see what he thinks...)

 

Ah. Thanks - that's very clear .

That syphon and associated pipework is your condensate drain. This drains away the liquid products of combustion - slightly acid water. When the boiler runs as normal, a lot of water is produced when the gas is burned, and the whole idea of a modern condensing boiler is to extract as much heat as possible from the hot flue gases - and when you cool these gases, water is condensed out (which will be slightly acidic due to the presence of, I guess, mainly carbon).

In use, that syphon fills up slowly, and then 'glugs' to empty down the pipe.

This pipe is clearly doing this from the system water instead. This suggests that the system water is leaking from inside the 'sealed' combustion chamber. Ok, I guess it could be a pipe connector or some other part - I've no idea what a W-B boiler is like inside the chamber - but the main component in there that holds water is the heat exchanger (the part which is heated by the burner and has the system water going through it.)

The engineer is asking you to check the copper pipe - that's the pressure safety release pipe, and this would indicate a leaking PRV (most likely caused by a faulty/discharged exp vessel).

Does the guy know yet the water is coming out the plastic condensate pipe? Has he been to actually look, or is he asking all this over the phone... .

Anyways, it's clearly gonna get sorted soon. ish.

 

I'm still leaning towards the heat exchanger, but I hope I'm wrong but it ain't looking good.
Once you get this sorted Richard make sure you chase the first engineer for some money back.

Good luck, I hope the outcome is a gentle one.

 

I'm very optimistic that this will be sorted out chust fine .

W-B are on the case, and even tho' the guy seems reluctant to blame the exchanger at the mo', if it does turn out to be that I have no doubt W-B will either pay up voluntarily or can be obliged to do so. Perhaps the fact the engineer is not particularly considering the exchanger as being at fault means that it's a part that rarely 'goes' on these machines? In which case the chances of them replacing it are even greater - it must have been inherently faulty?

Anyways, let the engineer do his checks and report back please, Richard.

(As p-boy says, you could 'have' that other guy quite easily - get your money back if you were so inclined. But, his only saving grace was that he was cheap... Another - similar - thread on here had the customer seemingly charged many £100's for having a second vessel fitted. And that didn't sort it either. I'll have to try and find that thread again...)