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gas installation pipe bonding [again]

"My head is in a spin, my feet dont touch the ground..."  - I think I am just wanting to unload my head to the almighty interweb (at least it is not to that facebook thingy) and in that, it will heal. :)


A description: a gas meter is in its cupboard outside on the side of a house and the service pipe coming out of the ground to it, at this stage, I am assuming to be conductive (or not plastic). The bare copper installation pipe from the meter, comes out of the top of the cupboard, goes  up the wall and around the outside of the house (at a touchable height) to the opposite side, a run of about 12 metres, where it enters the building though the wall and attaches to the boiler.  I am told this is quite common.


As an aside, for now, the visiting gas engineer said to the property owners, that because of how it is run, he wanted to see some bonding connected inside the meter cupboard on the installation pipe side , not elsewhere, or it would get a notice. *


What I am curious about is the approach to running an accessible [and conductive] pipe aroung the outside of a house (rather than getting it inside immediately) and bonded to the MET when there could be a fault on the installation.  It must be in the similar vein as  a small 'class one' light fitting being installed on the wall outside, that this is seen as an allowable potential shock risk even when it would be accessible for such a distance as it were when 'lively' ?   Or am I over-thinking this, or just getting it all wrong (as is my wont) with a "there is no issue here actually".


Regards

Habs


* I am starting to dislike use of some partial plastic pipe alterations in properties.  Keeping it brief as this is just part of the 'aside' comments: there are plastic sections a little after the copper 'out/return' pipes on the boiler which disappear into the house structure to goodness knows where.  Something else, or the copper pipe still visible elsewhere servicing radiators and so forth, seems to be keeping those parts extraneous. With a lot of pipe 'buried', it is quite tricky to spot whats going on.   As it happens, there is a MEB cable clamped to a copper pipe feeding a radiator on an internal wall, which then runs through the wall to the  MET on the other side.  This would seem to be doing its job for all the extaneous parts (gas and water connected) when assessing with it connected/disconnected. The connection is not in the ideal position, open to risks of being disconnected from more [future] alterations but it is working and perhaps the previous sparks decided this was the best to be done in the circumstances.  Its a bonding conundrum to find a good solution - if only it were all plastic, or still all copper...ho hum.
Parents
  • Now then, a bit more detail - sorry, its wordy but I've tried to be brief.  This is a bungalow affair btw (with not habitable/used roof spaces).


    The only apparant MEB is as previouslly noted, on a copper riser to the central heating radiator and fed through internal wall to the MET.   There have been previous extensive works with plumbing.


    Installation pipe to boiler parts:


    The gas service service pipe is still presumed to be metal at this stage and comes out of ground into the meter cupboard mounted externally.  The bare copper customer installation pipe comes out of meter, then out of bottom of the meter cupboard, then loops up and around the house, still externally and for the ~12m, where it goes into the house through the wall. Once inside, it is inaccessible being enclosed in a wooden boxing for a short section going into the roof space. It comes out of the roof space a small run later and immediately down to the boiler in a short straight run.  None of this is or has been MEB'd for some reason, despite previous works.


    Reasonably, the only section of that pipe that is readily accessible *internally* is it the ~80cm straight run down from the ceiling into the boiler casing (and its subsequent inlet connection to the boiler). Only half of that 80cm run, from the ceiling, is touchable metal and the rest down to the boiler appears shrouded in a plastic pipe until just into the boiler casing at the back. Even the touchable part cant be reached without ladder/steps etc.


    From underneath the boiler, the internal installation pipes (central heating and hot water) leave the boiler (hot water goes via a sink tap) in copper surface-mounted for a few metres and then all go into plastic pipes, which then run into a floor void to not be seen again rising. The cold water feed to the boiler (going via the sink tap) in copper for the last few metres up to the boiler, is also coming out of the floor void having been delivered to that point via plastic pipe (see later comment *).


    Question: based on the above, would any of the above,  up to the plastic pipework joints  need MEB  ?   My tentative thoughts, yes; because for external electricity network faults only (unless the boiler CPC could introduce installation faults), all the copper piping up to and leaving the boiler would be affected due to the the extranous copper pipe from the gas meter and its [presumed metal] service pipe.  I give way to be corrected/debated/enhanced.


    Question: where would one bond that part?    The only 'as it enters first habitable space', is the short length unsleaved section at the ceiling level above the boiler. This point is much further away from the MET, than the gas engineer suggested point of bonding at the  customer installation pipe at the gas meter.  Either bond point will still 'liven' up the external pipe route, so it really is a just a matter of  whether the 'at point of entry' is critical re: accidental removal of the bonding/branching probs. For this case in question, I doubt it matters overly.   Again I give way to be corrected/debated/enhanced.


    Downstream (after plastic sections) central heating parts:


    Now then, what happens after the plastic pipe conversions mentioned above and why is there a MEB (or was/is it an additional bond before the internal plastic pipe works !) from the central heating pipe work to the MET by the consumer unit.


    Well as mentioned at the outset, it would appear that despite the plastic piping upstream, seemingly the rest of the central heating pipe work is still all in copper and appears to be introducing an earth potential - running on/in the ground soil under the floors, damp conditions, or some other reason.   That may explain why the previous electricians  had this rad-to-MET bond in place.


    I'm told there has been a lot of previous work done at this place, new boiler, new plastic pipe works (new bathroom) and possible new consumer unit...but no paper work to be seen.  What stops a plumber coming along and  banging in plastic here and there and not realise about bonding implications: "hey look, I'm going to use plastic for this bit, but you may need an electrician to come in to check the bonding is still ok when I'm finished"  :)    Or may be, any previous electrical works have not check bonding was up to scratch.  Who knows.  ho hum.


    * (further note from earlier).


    The water supply to the property comes in under the wooden floor of a long hall. There is  a small access hatch (well, lifting some cut floor boards would be more accurate) in the floor under the main door footwell, to access the stop cock (its actually quite hard to get to !) .  The pipe runs under the floor, inaccessible (excepting the hatch access), until it appears to be  interrupted by a plastic joint insert and a little further is converted into the plastic pipe as mentioned earlier.  Its hard to see it all unfortunately.


    Question: does this need bonding ?   My thoughts, if reaching down to the stop cock (one has to lay on the wooden [and carpeted] floor!) and not being able to simultaneously touch any other parts, then no; because  its not accessible other than that and whats the risk; additionally it turns into plastic before any other usage point. Again I give way to correction etc.



    Summary:


    I feel that a MEB bond on the main incoming gas pipe is needed  (subject to confirmation assessment/clarification) for the boiler and other co-located copper extraneous copper pipe parts (where to do that is a matter of choice).   The MEB (or additional bonding ) that is still present internally at the central heating pipe downstream should be retained as for whatever reason, testing (< 25kOhms) shows it is still 'earthy'.


    Regards and sorry to swallow up so much space etc.  Thank you for the previous comments. etc.  Apolgoes for grammar and spelling.   Any comments to any of the above greatfully received.
Reply
  • Now then, a bit more detail - sorry, its wordy but I've tried to be brief.  This is a bungalow affair btw (with not habitable/used roof spaces).


    The only apparant MEB is as previouslly noted, on a copper riser to the central heating radiator and fed through internal wall to the MET.   There have been previous extensive works with plumbing.


    Installation pipe to boiler parts:


    The gas service service pipe is still presumed to be metal at this stage and comes out of ground into the meter cupboard mounted externally.  The bare copper customer installation pipe comes out of meter, then out of bottom of the meter cupboard, then loops up and around the house, still externally and for the ~12m, where it goes into the house through the wall. Once inside, it is inaccessible being enclosed in a wooden boxing for a short section going into the roof space. It comes out of the roof space a small run later and immediately down to the boiler in a short straight run.  None of this is or has been MEB'd for some reason, despite previous works.


    Reasonably, the only section of that pipe that is readily accessible *internally* is it the ~80cm straight run down from the ceiling into the boiler casing (and its subsequent inlet connection to the boiler). Only half of that 80cm run, from the ceiling, is touchable metal and the rest down to the boiler appears shrouded in a plastic pipe until just into the boiler casing at the back. Even the touchable part cant be reached without ladder/steps etc.


    From underneath the boiler, the internal installation pipes (central heating and hot water) leave the boiler (hot water goes via a sink tap) in copper surface-mounted for a few metres and then all go into plastic pipes, which then run into a floor void to not be seen again rising. The cold water feed to the boiler (going via the sink tap) in copper for the last few metres up to the boiler, is also coming out of the floor void having been delivered to that point via plastic pipe (see later comment *).


    Question: based on the above, would any of the above,  up to the plastic pipework joints  need MEB  ?   My tentative thoughts, yes; because for external electricity network faults only (unless the boiler CPC could introduce installation faults), all the copper piping up to and leaving the boiler would be affected due to the the extranous copper pipe from the gas meter and its [presumed metal] service pipe.  I give way to be corrected/debated/enhanced.


    Question: where would one bond that part?    The only 'as it enters first habitable space', is the short length unsleaved section at the ceiling level above the boiler. This point is much further away from the MET, than the gas engineer suggested point of bonding at the  customer installation pipe at the gas meter.  Either bond point will still 'liven' up the external pipe route, so it really is a just a matter of  whether the 'at point of entry' is critical re: accidental removal of the bonding/branching probs. For this case in question, I doubt it matters overly.   Again I give way to be corrected/debated/enhanced.


    Downstream (after plastic sections) central heating parts:


    Now then, what happens after the plastic pipe conversions mentioned above and why is there a MEB (or was/is it an additional bond before the internal plastic pipe works !) from the central heating pipe work to the MET by the consumer unit.


    Well as mentioned at the outset, it would appear that despite the plastic piping upstream, seemingly the rest of the central heating pipe work is still all in copper and appears to be introducing an earth potential - running on/in the ground soil under the floors, damp conditions, or some other reason.   That may explain why the previous electricians  had this rad-to-MET bond in place.


    I'm told there has been a lot of previous work done at this place, new boiler, new plastic pipe works (new bathroom) and possible new consumer unit...but no paper work to be seen.  What stops a plumber coming along and  banging in plastic here and there and not realise about bonding implications: "hey look, I'm going to use plastic for this bit, but you may need an electrician to come in to check the bonding is still ok when I'm finished"  :)    Or may be, any previous electrical works have not check bonding was up to scratch.  Who knows.  ho hum.


    * (further note from earlier).


    The water supply to the property comes in under the wooden floor of a long hall. There is  a small access hatch (well, lifting some cut floor boards would be more accurate) in the floor under the main door footwell, to access the stop cock (its actually quite hard to get to !) .  The pipe runs under the floor, inaccessible (excepting the hatch access), until it appears to be  interrupted by a plastic joint insert and a little further is converted into the plastic pipe as mentioned earlier.  Its hard to see it all unfortunately.


    Question: does this need bonding ?   My thoughts, if reaching down to the stop cock (one has to lay on the wooden [and carpeted] floor!) and not being able to simultaneously touch any other parts, then no; because  its not accessible other than that and whats the risk; additionally it turns into plastic before any other usage point. Again I give way to correction etc.



    Summary:


    I feel that a MEB bond on the main incoming gas pipe is needed  (subject to confirmation assessment/clarification) for the boiler and other co-located copper extraneous copper pipe parts (where to do that is a matter of choice).   The MEB (or additional bonding ) that is still present internally at the central heating pipe downstream should be retained as for whatever reason, testing (< 25kOhms) shows it is still 'earthy'.


    Regards and sorry to swallow up so much space etc.  Thank you for the previous comments. etc.  Apolgoes for grammar and spelling.   Any comments to any of the above greatfully received.
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