WORCESTER GREENSTAR 30SI Leaking

[Boxa]

Hi there all.
I have a Worcester Greenstar 30 SI combi boiler which has developed a leak.
If you are looking at the boiler from the front, underneath in the back right hand corner there is a threaded pipe connected to nothing poking down.
It appears that this threaded pipe is attached to some kind of plastic pipe above, with ??? some kind of valve a few inches above that.
Well, the leak is coming from hear everytime the central heating is turned on & the pressure rises to around 2 bar/a bit above.
The problem is acces, as the boiler is set against a wall.
Just wondered if anyone out there had some advice/thoughts.
Many thanks in advance,
Boxa.

 

[kevplumb]

first thought is prv

View media item 17263
no 46

 

[ServiceNumpty]

Yep, it is the prv, doesn't sound like it has been piped up to outside.

 

[Boxa]

Hi there lads & first & foremost thanks for the speedy reply.
I'm not just saying it, but my first thoughts were that it was the prv, however, my reasons for then discounting it were a) it wasn't piped to the outside (although having said that, there was a cupped nut screwed on to it, with an olive inside, as if it was going to be piped but then the fitter decided not to!!) and b) there is a pvc pipe going from the underneath of the boiler (frontish left hand side) to outside, which I asumed was the prv/overflow.
I have paid a bit more attention to it over the last few hours & one thing I have noticed is that the 'resting' pressure is just over 1 bar. However, when I turn the central heating on, this rises considerably (to just over 2 & then I turned the central heating off) I must add, that as the pressure was rising, the pipe to the outside was giving off plenty of steam (it's a bit to dark at the mo to see if it' sdripping water, but I would asume it is).
I'm going to bleed all the radiators in case there is a lot of air in the system. Does any of the above shed any more light?
Thanks once again for your replies, much appreciated.
Boxa

 

[ServiceNumpty]

The black flue will 'steam' in cold damp conditions, it is water vapour and perfectly normal. The pressure rise is also normal to 2 bar. The waste pipe is your condense waste. The expansion vessel may need topping up.

 

[kevplumb]

b) there is a pvc pipe going from the underneath of the boiler (frontish left hand side) to outside, which I asumed was the prv/overflow.

condense drain

 

[Boxa]

OK, so this is the point where I think you satrt loosing me
The pipe outside steaming I was fine with, condensation as you mentioned
However, firstly, are the pipe going to the outside & the one which just points down then two different kind of overflows/prv's?
Also, is it normal then for the pressure to rise 1 bar (and possibly more) when the central heating is on. I appreciate it would increase with the rise in temperature, just didn't think it would be that much.
Finally, condense vessel topping up & condense drain is where abouts I loose it! I have topped the system up, but not sure what you mean by topping up the condense drain?
Many thanks once again, well impressed by your rapid responses
Cheers,
Paul.

 

[APHSLTD]

OK, so this is the point where I think you satrt loosing me
The pipe outside steaming I was fine with, condensation as you mentioned
However, firstly, are the pipe going to the outside & the one which just points down then two different kind of overflows/prv's?

Yes one is the condensate drain from the boiler which should go to a waste pipe, gulley or soakaway. The prv should go outside and ideally terminate to a gulley or at low level with a guard but 99 times out of 100 is just turned back to the wall wich is acceptable.

[/quote] Also, is it normal then for the pressure to rise 1 bar (and possibly more) when the central heating is on. [/quote]

That would depend on how big the system is, as a general rule provided it does not go above 2.5 Bar all is well.

 

[XKESTONMAN]

sounds like the condensate plastic pipe union that connects to condensate trap.
the nut has a washer inside,it might need replacing.
they often leak. i some times p.t.f .e the thread

 

[Boxa]

Hi there again & thanks as always for getting back with your replies.
As yet, the only thing I have done is reduce the temp on the central heating to about 4 (I appreciate that's a pretty arbitrary number!) I did have a quick play around with the 'down pipe' but it just seems to twist a lot!
Anyway, the pressure now keeps below 2 Bar, which seems to prevent the leaking.
However, I still have a couple of issues & also some advice on what someone else has told me.
Reducing the temp to '4' may well have resolved the problem for now, but I do not know whether that is going to be enough for the winter (I live up north ya know ) and therefore I may well have to increase the temp again and consequently the leak will return
Is the increase in pressure by 1 Bar (sometimes even a bit more) acceptable, even if it does keep below 2.5 (which it pushes pretty close to when the temp is on '5'
Finally, and related to the last point, someone has said that there is some kind of air pressure thingy in the tank, which should have a pressure of about 7lb and this help to reduce large increase in pressure within the tank. The likelihood, they say, is that some air has been lost from here and it just needs topping up.
Hope the above helps & thanks once again for all your help, I cannot tell you how much it has helped & also helped re a bit of peace of mind, as with the pressure raising that much, I was getting a little concerned.
Oh, one last thing a) The boiler is about 4 years old & has not been serviced yet & b) was thinking about getting some kind of insurance for it... any recommendations? (I understand if no-one is allowed to recommend stuff like this on the forum, I appreciate that may go against the general ethos of the site)
Many thanks in advance again & keep up the good work.... fantastic site,
Boxa.

 

[APHSLTD]

The ammount the pressure rises by during expansion will depend on the water content of the system, the 30Si only has a 6 litre expansion vessel which is good for about 9 to 10KW of heating load. To check if it needs re-pressurised you will need to drop the system pressure to zero and test with a tyre pressure guage. The test point (black cap on a red EV) is behind the boiler at the top IIRC it should be 0.75bar.

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• APHSLTD
• 30 Nov 2009
• 1

Depending on the size of your system you may need an additional EV.

The PRV should not be letting by until 3 bar though. It may be faulty or the pressure guage may be faulty (have seen a few on the Si's).

 

[gigz]

And get your installer back to terminate the prv cos if it blows you (or anyone in the vicinity) could be scalded.

 

[Boxa]

Hi there again & thanks for your replies as always.
I found the test point re the EV. It was a little difficult testing the pressure exactly, due to the lack of accuracy on my pressure gauge. Nevertheless, I think I had it at about .75 Bar & it has made no difference.
As I mentioned earlier, I placed the temp down to '4' and this kept the pressure at about 2 Bar & there was no leak.
The boiler is actually at my partners place & I have spoken to her & she has had to up the temp a bit due to it being a bit cold indoors (4.5) so it will be interesting to see if it begins to leak...
If I can just ask one question though, you have referred to my problem being with the PRV, however I was under the impression it was the condensation tank...
Thanks as always lads,
Boxa.

 

[gigz]

Hi there all.

If you are looking at the boiler from the front, underneath in the back right hand corner there is a threaded pipe connected to nothing poking down.
It appears that this threaded pipe is attached to some kind of plastic pipe above, with ??? some kind of valve a few inches above that.

The condense trap is on the left hand side as you look at the boiler and should be plastic all the way, the PRV is on the left (brass valve with a red lever attached) and should be in copper and terminated safely outside.

 

[Boxa]

Hi there & thanks for your reply.
As I mentioned previously, on the right hand side to the back there is a copper threaded pip poking down with nothing attached... so you are saying this is the PRV?
On the left hand side, nearer to the front, there is a plastic pipe which does go outside, you are saying this is the condense pipe?
This is the opposite of what I thought was being said. Therefore, am I right in saying whoever plumbed it in in the first place has basically c0cked it up?
Many thanks as always,
Boxa.