No hot water - do I need 28MM gas pipe?

Discussion in 'Plumbers' Talk' started by Harriet Davies, Jan 12, 2018 at 4:28 PM.

  1. Harriet Davies

    Harriet Davies New Member

    I had a new boiler fitted 3 years ago and the existing 22 mm pipe was used. It has been cutting out when running the hot water and now a service company have turned it down. they say it needs upgrading to a 28mm pipe to meet current standards?

    Should the original fitter have done this at the time? They connected it to the original 22 pipe as they said this would be sufficient. It has also leaked water from time to time, is this because the 22 pipe is insufficient? I am worried about a bill for £s
     
  2. jonathanc

    jonathanc Active Member

    are they talking about the gas pipe supplying it? if so it has nothing to do with the leak.

    not sure what you mean about the service company turning it down - need more info on that
     
  3. Dr Bodgit

    Dr Bodgit Well-Known Member

    Sounds like balderdash. Might have poor gas pressure which is a totally different can of worms.
     
  4. jonathanc

    jonathanc Active Member

    by guess: service company don't know what is going on and are trying to use gap pipe as an excuse for wriggling out of fixing the problem, but then that is a guess. We need to know more....
     
  5. Isitreally

    Isitreally Active Member

    28mm gas pipe?? Do you live in a mansion :D:D
     
  6. Harriet Davies

    Harriet Davies New Member

    Thanks guys, we live in a normal semi with an attic. The boiler has been cutting out when running the hot water for a while but otherwise ok. I needed a boiler check to get a service plan and they have turned it down saying the gas pipe was to small at 22mm. They say we need remedial work to get it all at 28mm as this is the legislation. It is a vaillant 937 ECOTec and the manual says 22mm is required not 28mm. It is a long pipe run though.
     
  7. Harriet Davies

    Harriet Davies New Member

    Gas pressure was checked today and is 24 at the meter
     
  8. Isitreally

    Isitreally Active Member


    The pipe supplying your house probably isn't even 28mm.
     
  9. Dr Bodgit

    Dr Bodgit Well-Known Member

    I just googled, 15 millibars gas pressure is normal, so if the 24 is 24 millibars then gas pressure is more than fine. I wonder if your water pressure is lacking...its a combi boiler right?
     
  10. Isitreally

    Isitreally Active Member


    What was it at the boiler.?
     
  11. Harriet Davies

    Harriet Davies New Member

    It was 13 at the boiler - it is a combi boiler
     
  12. Harriet Davies

    Harriet Davies New Member

    it has leaked water on and off
     
  13. Devil's Advocate

    Devil's Advocate Well-Known Member

    Who measured this, and what did they conclude?

    Yes, if the pipe run is longish, 22mm can be inadequate.

    There are calcs to work this out before install - always better than guesswork, especially when it's known it's a 'long' run.


    (The water leak has nothing to do with the gas pressure).

    If it turns out that you really do need 28mm pipe, then that's what you need. Yes, it'll cost - but you'd have had to pay that in the first place as well.
     
  14. jonathanc

    jonathanc Active Member

    Right you say sometimes no hot water. Is there a problem with heating as well?
     
  15. retiredsparks

    retiredsparks Well-Known Member

    Had new boiler moved from landing to attic 2 years ago.
    22 mm existing... 4 bed normal house.
    guys put in 28 from meter to new boiler vertical run.
    Doubt they did it for fun ?
    Rs
     
  16. Harriet Davies

    Harriet Davies New Member

    Heating is ok, just water affected
     
  17. Devil's Advocate

    Devil's Advocate Well-Known Member

    DHW with a combi is when it draws MAX gas, so that's no surprise.
     
  18. retiredsparks

    retiredsparks Well-Known Member

    Harriet
    The installers would had completed a commissioning report and left it with the boiler.
    The performance readings will be in there.
    Any guarantee...who were the installers....call them back ........speak to the boiler makers.
    Rs
     
  19. jonathanc

    jonathanc Active Member

    Nope either because boiler spec, pipe length or profit....
     
  20. retiredsparks

    retiredsparks Well-Known Member

    It was a worcester CDI compact......and at the price they did the job for it was not for profit.....lol
    Also replaced 2 rads and installed a magnetic filter ...and a fill lop and gauge in old air cupboard.. at my request.
    It has a 8 year(I think) warranty on it..providing its serviced yearly... and they suggested that if I wished I was free to have the install inspected free of charge by WorcesterBosch.
    2 doors down...same house...same boiler shift...28mm pipe same run up wall...by British Gas.
    RS
     

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