Pipe from pressure release valve on a combi

Discussion in 'Plumbing and Central Heating' started by StuB, 9 Nov 2006.

  1. StuB

    StuB

    Joined:
    14 Mar 2004
    Messages:
    44
    Thanks Received:
    2
    Country:
    United Kingdom
    Hi All,

    Currently having a new Worcester Bosch 35CDi boiler fitted by a Corgi guy and for the pipe from the Pressure relief valve he plans to use a copper tube for the first 0.6 m and then drop it into a plastic waste pipe that'll go into and then across the concrete floor and finally be deposited in the drain outside.

    I was under the understanding that this pipe should be copper and should end up venting outside in a position that can't splash anyone.

    Can anyone tell me the correct way it should be done?

    Also could the same plastic waste pipe be used as the waste for a washing machine and if a condensing boiler is used the waste condensate as well?

    Cheers

    Stu
     
  2. Sponsored Links
  3. scatmanjohn

    scatmanjohn

    Joined:
    2 Nov 2005
    Messages:
    3,391
    Thanks Received:
    237
    Country:
    United Kingdom
    It needs to be copper and has to terminate in a safe place that is available for inspection.
     
  4. StuB

    StuB

    Joined:
    14 Mar 2004
    Messages:
    44
    Thanks Received:
    2
    Country:
    United Kingdom
    Thanks for that, so I take it what's shown in the image at the bottom of this mail is not allowed then as the prv pipe goes into a plastic waste pipe which then joins with the washing machine and then goes under a concrete floor and outside.

    Also if a Corgi fitter says something like this is correct most homeowners wouldn't know any different so do I take it you should be able to take the Corgi guys word for it (I guess you are paying for there (in)competency) and any subsequent problems are his responsibility or does it come down to the home owner?

    What is the procedure to challenge something they say is correct and if Corgi say it should be a copper pipe all of the way then is that the law or a recommendation?

    Cheers

    Stu

    [​IMG]
     
  5. arfurrrr

    arfurrrr

    Joined:
    4 Oct 2006
    Messages:
    1,541
    Thanks Received:
    316
    Location:
    Yorkshire
    Country:
    United Kingdom
    is this boiler a condensing boiler as i dont see a condensate waste pipe , if its not have you got an exemption certificate ?


    can you confirm the GCN (gas council no :) should start G.C.N 47

    arf
     
  6. StuB

    StuB

    Joined:
    14 Mar 2004
    Messages:
    44
    Thanks Received:
    2
    Country:
    United Kingdom
    Well spotted that man. This is another bone of contention as I asked for a Worcester Bosch 35CDi and they've installed a 35CDi II RSF which I didn't realise until yesterday isn't a condensing boiler.

    From what I've seen and what the guy has said I believe it does qualify for an exemption based on it being an old semi-detached house with a back boiler being removed so the boiler is in a different room and there are flue and waste issues.

    I'm very annoyed that he didn't tell me he was fitting a non condensing boiler and he's now saying it can't be changed because you can't use the waste for condensate, pressure release valve and a washing machine and fitting another pipe would be very difficult because of the location.

    My understanding after asking around it that the condensate and the washing machine can share a waste but the pressure release valve must have it's own copper pipe to the outside world?

    The easiest way to install a copper PRV pipe would be to go up and over the ceiling to the outside wall. Is this allowed?

    Throroughly fed up that it's causing this grief and didn't expect it when using a Corgi registered guy (and he is as I've checked).

    Any help that could be offered would be gratefully received as I need to sort this out asap.

    I take it you don't need the GCN now I've told you the model but if you do I can get it for you later.

    Cheers

    Stu
     
  7. div69

    div69

    Joined:
    29 Dec 2004
    Messages:
    51
    Thanks Received:
    0
    Country:
    United Kingdom
    regarding the pressure relief valve pipework, it has to be copper all the way as per the building regs, as the article I quoted in the post link below states http://www.diynot.com/forums/viewtopic.php?t=64385&highlight=
    That aside, for the joint between copper & plastic, whether its done like on yours or a pushfit was used that joint should be at least a meter away from the boiler because when the pressure relief valve activates there may be very hot water discharging, hence heating the copper pipe and possibly affecting the copper/plastic joint. If this joint breaks because of the high temperature you'll be getting all this mess in your kitchen or whereever the boiler was installed, possibly causing injury if someone is close to it.
     
  8. DP

    DP

    Joined:
    10 Dec 2003
    Messages:
    15,188
    Thanks Received:
    3,375
    Location:
    Glasgow
    Country:
    United Kingdom
    It looks like one where one would have to sit on the fence for this particular scenario.

    Vent pipe discharge point has to be visible to eyeball discharge should the PRV lift to control system pressure. In above case this visibilty is offered by the tundish.

    Plastic pipe will indeed 'go plastic' at temperature around 125 degree C. Different pipes, different fail temeratures. Pipe used (drain pipe) is microPVC. It is made from materials that are very different from those used for plumbing flow and returns/ hot and cold supplies. Not only that, there is no pressure involved during discharge of hot water and steam.

    This brings me to another point. The regs say you must have a gas pipe and mains wires saperated by 150mm. That is in ideal world where the installer is wiring, plumbing and laying gas pipes. Have been to houses where the mains is right next to the gas meter, and cables, heaven help us, run alongside gas pipes and water pipes.
     
  9. StuB

    StuB

    Joined:
    14 Mar 2004
    Messages:
    44
    Thanks Received:
    2
    Country:
    United Kingdom
    Thanks for the replies guys, they're very helpful and it's interesting to hear everyones opinions on these kind of things.

    A copper pipe from the prv to the outside world is what I understood it should be from comments here and elsewhere but I've just had a conversation with a technical guy at Worcester Bosch and he says, as DP does that because water from the prv pipe can be seen via the Tundish it should be ok although it's not recommended.

    Interesting to note that it should be more than 1 metre from the boiler though.

    Should I push to get the guy to change the current install of the PRV? Installing a separate copper pipe will be very difficult with the boiler being in it's current position as it's on the wall of the property ajoining us, the floors are concrete and it's about 12m either way to the front or back of the house and these are all solid floors too.

    Also should I insist that the guy changes the boiler for a condensing one?

    Are the running costs likely to be that different between a condensing and non condensing boiler?

    Also I took at offcut of the waste pipe and stuck it in a pan of boiling water for 10 mins and it did soften but I had to squeeze it pretty hard with a pair of cooking tongues to squash it down.

    DP,

    Am I right in thinking your comment about the mains and gas being too close is a general comment and not just about this install as the switch is more than 150mm away from the gas pipe?
     
  10. Sponsored Links
  11. arfurrrr

    arfurrrr

    Joined:
    4 Oct 2006
    Messages:
    1,541
    Thanks Received:
    316
    Location:
    Yorkshire
    Country:
    United Kingdom
    Where is your quote from this guy ? does it say owt about non condensing bolier ? Waste disposal anit a problem as your washing machine is next to the boiler, flue termination is , but manufacturers know this and produce a large range ! Have you seen his Corgi Card ? is it in date and does he have the correct qualification to work on boilers ?

    Do you know about gas work notification ? Does the installer ?

    can you post a picture of where the flue terminates , don`t pay owt yet .
     
  12. StuB

    StuB

    Joined:
    14 Mar 2004
    Messages:
    44
    Thanks Received:
    2
    Country:
    United Kingdom
    Hi Arfurrr,

    Are you ready for a long story, sorry to bore you all :)

    It's become a whole messy affair. There is no original written quote just a verbal one (and yes I'm now starting to understand this is a mistake) to install a heating system into our 3.5 bedroom 2 bathroom house.

    The install is being done at the same time as an extension and I asked for new radiators in the new rooms and replacement of the older existing ones (this left four original fairly modern ones). There are now 12 rads in total of which a number of these are quite small (some rooms have 2 small rads instead of one large).

    Also combined into the quote where things like plumbing in new kitchen sink and bathroom, outside taps and connecting of gas meter that had to be moved.

    My only other stipulation was regarding the boiler being a decent make and capable of a decent flow rate so a bath or shower and a tap could be run at the same time and based on this and speaking to friends with combis I suggested in my opinion something that can handle around 14l/m would probably suffice.

    The quote for the job was given in March/April this year and the first fit work was done as the extension was being done in May. He turned up with a 25CDi to install which I was not happy at and so told him not to install it as that's not what I'd asked for. He wasn't chuffed at this so said what exactly did I want. I said I wanted a 35CDi which he went off and fetched and then hung on the wall. What I didn't realise is that the 35CDi II RSF he'd turned up with was a non condensing boiler and was different to a 35CDi, this was the next mistake.

    Our first child was born in May and due to a few complications all building work stopped for a couple of months which in turn stopped him from completing the second fit.

    I called him at the end of August telling him we were now ready and he finally came back to finish the work this week.

    It was only when I looked in the boiler manual that was around while they were fitting it that I realised that there was no function to preheat the water which I thought the 35 CDI model did that made me check the Worcester Bosch website and realised the boiler they were fitting as not a 35 CDi and was the non condensing model.

    When I raised this with him he said that the house didn't need a condensing boiler as it's exempt due to the points system.

    I don't have a picture of the flue termination but can get one later but the flue terminates on the pitched tiled roof above the peak, of a single storey building and the nearest window (on second floor) is about 2.5m away and there is a large velux about 2 meters away in the other direction.

    As I'm reading up on this I'm hearing about the gas work notification which I understand as the Corgi guy should notify Corgi of the install along with a copy of the exemption certificate. Is this correct? Again I'd expect him to know this but I wouldn't want to guarantee it.

    I haven't seen the guys Corgi card but I did call Corgi when I got the quote and also again just the other day and gave them his name and company name to ask if he is qualified to do the work and he was registered for gas and central heating work amongst other things and they confirmed he was.

    The bill has been part paid but I still owe him a further £1300 which I'm not going to pay until this is sorted out satisfactorarily.

    Your help and advice is very gratefully received.

    Cheers

    Stu



     
  13. scatmanjohn

    scatmanjohn

    Joined:
    2 Nov 2005
    Messages:
    3,391
    Thanks Received:
    237
    Country:
    United Kingdom
    So lets get this straight.

    He turned up with a 25CDi which is a condensing boiler.
    So that means he was going to install it.

    He is now saying that a condensing boiler is not appropriate.

    He is leading you a merry dance i think.

    Ask him if he was going to install the 25cdi greenstar why could he not install a 35cdi greenstar.
     
  14. StuB

    StuB

    Joined:
    14 Mar 2004
    Messages:
    44
    Thanks Received:
    2
    Country:
    United Kingdom
    He says that the original he supplied was a 25CDi and was a condensing boiler but I seem to remember (although I'm not 100%) it looking very similar to the 35CDi II RSF and I believe the greenstar models look different.

    He says he supplied a 35CDi II RSF because that's what I asked for. I asked for a 35CDi, I was unaware there was another similarly named un condensing model and was expecting the condensing model.

    Am I right in thinking it would of been reasonable of him to of known the model he was supplying was a non condensing boiler and at least asked to be sure that's what I wanted as it shouldn't of been fitted nowadays

    'He is leading you a merry dance i think.'

    I think you're probably right hence the reason for me trying to get this sorted out now before he's paid and disappears. It's a shame as the lads that have been out have been good and turned up in the morning and done a full days work and the general workmanship of the pipework and install seems pretty good to me.

    Cheers

    Stu
     
  15. scatmanjohn

    scatmanjohn

    Joined:
    2 Nov 2005
    Messages:
    3,391
    Thanks Received:
    237
    Country:
    United Kingdom
    Hope he wasn't charging for the solder by the roll. :eek:

    Them joints are a joke (especially the joints on the bottom of the 15mm pipe). :eek:

    Bit off topic but has he flushed it because by the look of his pipework he likes his flux.
     
  16. StuB

    StuB

    Joined:
    14 Mar 2004
    Messages:
    44
    Thanks Received:
    2
    Country:
    United Kingdom
    I believe so but nothing would surprise me now

    So is the basic consensus tell him to change the boiler to what I asked for in the first place. This will obviously annoy him so is it worth telling him to remove the boiler and get someone else to supply and fit?
     
  17. scatmanjohn

    scatmanjohn

    Joined:
    2 Nov 2005
    Messages:
    3,391
    Thanks Received:
    237
    Country:
    United Kingdom
    I would say that you have a point.

    He was going to install the 25cdi (greenstar)

    So if that was me and someone said that they wanted a 35cdi i would have said "do you mean the 35cdi greenstar sir"

    I know what he will say.

    You asked for a 35cdi and thats what you have got.

    Did he not specify the boiler type in the quote.

    I still can't get my head round how he has got an exemption certificate when he was going to install a 25 cdi greenstar.
     
Loading...

Share This Page