Water supply pipe - earthing disconnected

Discussion in 'Electricians' Talk' started by backingline, Jan 3, 2010.

  1. backingline

    backingline New Member

    About a month ago, we had our old water supply pipe replaced under insurance. The replacement pipe is MDPE. I’ve just had a closer look at this where it comes into the house. The contractors seem to have disconnected the 16mm earth cable, which ran from ‘my’ side of the stop valve to the consumer’s earth terminal near the electricity meter. So now the internal water system is not earthed/bonded.

    The house is in London and has independent earthing, so it does not depend on the water supply pipe for its main earth. That much I understand. But could someone help me with a few points?

    1) Would it be fair to say the system is now less satisfactory/safe with regard to Part P or the wiring regs than it was before?

    2) Aren’t the contractors (from Thames Water) supposed to reinstate the bonding if they remove it? Are they legally obliged to?

    3) Are they at least legally obliged to warn the householder that they’ve disconnected the bonding?

    4) Realistically, how dangerous is it to leave the internal water pipes in their current state (ie, not bonded)?

    I’m going to ask the insurers to sort this lot out, but it strikes me that there must be hundreds of houses up and down the country that are now LESS safe as a result of ‘improvements’ to their water supply pipes.

    Any thoughts very welcome…
  2. nottsspark

    nottsspark New Member

    it sounds like the connection to the pipe may of originaly been on their side of the stop tap, they would have no reason at all to disconnect something on your side

    if it was on their side they have no requirement to put it back on, by an earth clamp from b and q and put it back yourself in the correct place. not having it is potentially dangerous under fault conditions
  3. seneca2

    seneca2 New Member

    Agree with nottspark, just buy an ec15 clamp from your local diy/plumbers/electrical shop and re-connect the bonding cable yourself, it does need to be there. (assuming the pipework in the house is metal, if it's all in plastic, no need)
  4. Removed 4

    Removed 4 New Member

    Water suppliers are obliged by the 'rules' to serve notice to the householder of the impending works. Having carried out the work, they are further required to issue the standard notice, which says (paraphrasing here) that the your earthing system may have been compromised by the recent work - and that you should seek advice from your electrician......

    This is a standard going back almost twenty years...

  5. backingline

    backingline New Member

    from OP
    Thanks for those replies. One of the problems is that 'my' side has moved - Thames Water replaced the stop tap much further up the wall so they could get the supply pipe in (original stop tap was almost at floor level). Yes, I know how to fix this - but the point is, should they be mucking around with bonding arrangements without telling people?? This is partly because I'm really fed up with Thames Water - they've really f*ed us about with imaginary stories of leaks, which then turned out to be their new meter...
  6. nottsspark

    nottsspark New Member

    in an ideal world they should but this is a water company.........they dont give a **** and as lucia said will have some legislation to cover their arses
  7. Removed 4

    Removed 4 New Member

    I've already told you, dear, that if the water company makes a significant change to your supply which might compromise your eathing arrangements, then they are obliged to inform you in writing. But the matter of earthing and bonding remains your responsibility whatever the change in supply from any utility.....

  8. JP.

    JP. Screwfix Select

    Must say I don't understand all this. The new water main is in MDPE which rises into the chaps property as I see it.

    Why all the fuss about an unconnected clamp as there can be no raised PD from the MDPE pipe.

    Granted the clamp is there, and of course fit it, but whats the prob and stuff?..I see no indications of reg breaches at the particular juncture portrayed by the OP.
  9. JP.

    JP. Screwfix Select

    After re-reading must agree that the earth bonding will have to be re-instated..a simple job. Don't forget to clean the pipe where the new clamp goes OP..and then check continuity and stuff before putting the earth cable into the cable clamp..you are looking at 0.05 ohms or less.
  10. NAPIT numpty

    NAPIT numpty New Member

    if it is 16mm IS it the Earthing conductor or over egged main bonding ............. is ther anything to the Cut-out?
  11. Coloumb

    Coloumb Well-Known Member

    backingline, are you saying that previously your water supply was fed by a metal pipe which has now been replaced by a plastic pipe? Was the clamp previously connected to the mains feed metal pipe and now is not?

    This is quite important to answer this question correctly.
  12. J.P

    J.P New Member

    OP is stoopid 4 postin tis ridiculous quest.
    The rest of ya are just stoopid.
    is it really that difficult?
    i suppose is 4 stoopids



  13. Jake'sDad

    Jake'sDad New Member

    If the water comes in in plastic it doesn't need bonding,
  14. seneca2

    seneca2 New Member

    If the water comes in in plastic it doesn't need bonding,
    But the rest of the pipework does if it's metal!
  15. Coloumb

    Coloumb Well-Known Member

    If the water comes in in plastic it doesn't need bonding,
    But the rest of the pipework does if it's metal!


    no it does not
  16. unphased

    unphased Screwfix Select

    Jake's dad and Ben

    If all the pipework inside the house is metal then it requires bonding back to the MET. It matters not what the supply pipe is; you are not earthing it you are bonding it. Lots of misunderstanding about this. Bonding brings pipework to equipotential with the earth.

  17. Coloumb

    Coloumb Well-Known Member

    up wrong again dude
  18. mr sillys

    mr sillys New Member

    coltoumb are you introducing a potential



  19. Coloumb

    Coloumb Well-Known Member

    bonding is only required if the metal part is likely to introduce a shock potential to the house, ie it's extraneous.

    if the metal pipework is not extraneous then how this POSSIBLY introduce a shock risk?
  20. Coloumb

    Coloumb Well-Known Member

    we have been over this a million times.

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