DO YOU NEED TO EARTH BOND PLASTIC WATER PIPES? 

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As an apprentice, this helped me alot. More on this topic please eFIXX!!!

"You can't apply bonding to protect from faulty installation elsewhere." I wholeheartedly disagree. Workmanship is always a variable when making standards, and overlapping protections save us every day.

The plastic pipe obviously doesn't make a direct connection to earth, but what about any metal pipe fittings further down the road? At mains voltage water can act as a conductor (or we wouldn't worry about IP rating for things exposed to damp environments) so while the path to earth via the pipe itself doesn't connect to earth directly under the house, surely there's a path to earth via the water in the pipe itself? I accept that the potential is probably a lot lower than the actual copper earth that comes into the building though, so likely wont be a problem, but I would still expect that there is the possibility of an issue there.

I knew it!!! I thought it did not make sense when my electrician said my incoming water mains must be bonded even though it comes through MDPE pipe. Glad this video sorts it out!

Your tutorials are excellent.

18th edition says no to bonding plastic incoming pipes. btw - It’s either earthing or bonding, not earth bonding. They’re two separate functions 👍🏻

I live in Germany. We have TNC-S and a plastic water pipe. The pipes in the house are made of copper and are bonded to the foundation earth. The house is almost 50 years old. As far as I know, the heating engineer has requested that the earthing is available, so the earthing is not at the inlet of the pipe but on the heating system. But that doesn't matter with copper tubes.

To the “I’d bond it anyway” brigade the video clearly shows that when it’s not extraneous it’s no different to any other metalwork in the property. If you “bond it anyway” you’re going to introduce a fault current that wouldn’t otherwise exist. We’re all about keeping fault currents away from people yet bonding an irrelevant piece of metal is increasing the chances of someone coming into contact with live metalwork. Or am I missing something?

We do the main bonding usually in the hot press in Ireland, under the sink would be supplementary bonding to the sink, but in the new regs due to lack of bonding points, ie no flange on sinks plastic pipes and flexible braided pipes. if we prove there's no earth path we don't have to bond, ie via insulation test .

There is the electrostatic potential, and the flow of water can still give a little charge. I have seen dust cling to plastic water pipes in use, although current is minimal the field is quite large.

Does this still apply when these water pipes are surface mounted on walls throughout an installation and include outside taps and electric water heaters? As exposed conductive parts, there is no question that they shouldn't become live, but what does the term 'under fault conditions' apply to? (Have bonded pipes in an installation like this recently)

Joe you cannot state that if the service pipework is plastic then it does not require main equipotential bonding. It is possible that elsewhere within the property that the installation copper pipework enters the true earth and comes back up again, and therefore can be deemed extraneous. A simple test to prove is what I do,....continuity test between the MET and the pipework. If the reading is

So out of interest on the EIC do you put N/A in the tick box then? Would this be sufficient or would you need to prove bonding is not necessary by providing a measured resistance value to prove it isn’t required ?

I've seen a voltage difference between cold and hot pipes within a house form when the hot water pipe heats up as a tap opens. I'm just wondering if in future a reg will come out with a bonding portion of pipe to bring the water to a zero potential.

I had a thing about 15 years ago . Plastic incoming main . All the pipe work in the flat was plastic. Customer had a electric shower and complained he got a nasty shock . Shower was about 8 foot away from the incoming plastic main. Couldn’t find anything wrong on testing. It was also a intermittent thing..After a lot of head scratching it was Infact a fault on an adjacent flats water heater .The element was faulty, so was the voltage operated trip. The fault was Infact traveling through the water in the plastic pipe into my customers flat and earthing through him when he was stood in the bath using the shower.. most tradesmen round here still use copper but if it’s plastic I get them to put a small copper section in so I can earth this so this sort of thing never happens again . This was a potentially dangerous situation that no one seems to consider

Good explanation, makes sense.

On a brand new install i would accept the non-bonding of plastic incoming water pipes ( what about plastic gas pipes then ? ) Existing installs can and do bring the risks of cables being found under floors etc resting on metal heating pipes etc ( but they could now be all plastic !) The discussion on protecting metal sinks on older BS7671 regs brought similar conflicting views didnt it ? Personally, I'd still bond and do continuity tests to verify integrity.

To muddy the waters, PME/TN-C-S installations are required to have an insulation joint the gas supply if it's via a metal pipe to stop it carrying any fault current. So does the gas pipework downstream of the IJ still need to be bonded? And what about the exposed metal pipework upstream of the IJ as that can't be bonded. FWIW the incoming water main is black MDPE so shouldn't need to be bonded but I ran a new 10mm² cable to avoid an argument with the commissioning electrician when I changed the CU.

This is to assume that the only connection point between the ground and the water pipe is the incoming pipe. An underground feed in conductive piping to a garden tap or outbuilding would do the same thing. There may be other possibilities too, whereby the property's internal conductive pipework has a connection to the ground. It may be rare, but it surprises me that it is not mentioned in the regs as a possibility. Of course, the most likely way that the copper piping would have a connection to the ground would be via a gas boiler if the incoming gas supply is via conductive pipe, but then the bonding on that ought to deal with the situation.

In a house with radiators that are plumbed with copper pipe; are the central heating water pipes bonded completely independently of the house water supply? Could disconnecting the water pipe bonding mess with the radiator bonding?

"We can't bond just to cover poor installation" This is a correct statement... However. I was receiving shocks and tingles from my New washing machine and kitchen sink, turns out Mice had chewed through the Flex feeding the washer. This left the live conductor touching the water feed pipe and therefore livened-up the whole unbonded house water installation. Makes you think ?

What if there is a bond wire to the cold water pipe inside the apartment. At some point, the plumber replaced the feeder pipe with PEX. Is there an easy way to check whether that was the main earth ground of the apartment, and would it need to be rebonded or to add earthing rods?

My plumber fitted a new stop tap, he used a plastic push fit connector onto the main water feed in then copper pipe then stop tap as it was live when he changed it. He left the bonding wire disconnected. Now because I have a plastic connector between the main feed and the house pipe work does it still need bonding as the old wire doesn’t reach to what’s left of the inlet feed pipe

My house has bonding in the bathroom, kitchen and down stairs loo. But the pipe bringing in the mains eater to the d s loo is plastic. All water supply pipes in the house are copper except the ufh on the ground floor. So if all copper pipes have bonding but I do not believe is bonded back to ground? So what is the point, think the house was built in the 70"s Should I bond the nearest pipe to the supply metal protective shield, which is under the stairs and the ufh manifold 22mm copper pipes are there to approx 1 meter away. Thanks for the thoughts on earth bonding and video.

My home in the US has plastic PEX piping and it is not bonded to the electrical service ground. Code does not require it. However, water is a conductor and water flows from buried metal pipe in the street and comes in contact with metal valves and fixtures in the home. Could a voltage potential be applied somewhere in the system, perhaps a faulty electric water heater element? Perhaps bonding at a location near the entrance via a stainless steel or brass pipe fitting might be a good idea?

tnx for video! very useful...

There's one more issue: The whole house is at "real earth" potential unless it's built on plastic foundations. Usually that doesn't matter, plaster, bricks and carpet aren't good conductors and the area we touch them is quite small. But now you have copper pipe through your whole house that is buried in brickwork. It makes contact over a quite large surface, plenty of parallel paths---and Ohm's law on parallel connections starts to raise its head. I'd recommend to measure the resistance between "real ground" and any touchable metallic object to decide if it should be bonded.

Hi Joe, I would still bond! The reason being that as water isteslf conducts electricity it becomes a return path and thefore a potential difference to the installations 'earth' value as regards an equipotential difference! Regards David

Like someone else has said I wondered about the water conducting. I am not an electrician, but have this question which many DIYers must have come across. Metal pipe into the house and to the sink with bonding at the taps. Kitchen redone with all plastic plumbing from the point the water comes into the kitchen. Stainless steel sink fitted with metal taps, but plastic tails and plastic as far as the kitchen door. I assumed that because the sink is insulated now there was no point in any sort of bonding. In fact even when there was bonding I was never sure of the logic on a metal sink. I sort of thought I understood on a plastic or pot one that connecting the hot pipe to the cold gave a route back to earth so that seemed sensible.

Most of what I was going to say has been covered below, especially Tom Capons post, but all you need to do is ask a simple question. Will bonding it make the installation less safe? obviously not, Will bonding make the installation more safe in the event of a fault? Yes it will, so you put it back. you do not know that plastic pipe has not been installed elswhere in the building that has isolated this part of the conductive pipework from other bonding at boilers, immersion heaters etc. Regs are there to provide safety( or used to be!), It is the engineers job to ensure safety, not the regs, and anything done to enhance safety is good. Mere compliance is not good enough, just an A*se covering excercise. The attitude that," the regs say I dont have to do it so I won't" is what kills people. I was trained on IEE 14th metric 1970 and have CGND Electrical Engineering. I am afraid I have little faith in the IET as the regs are difficult to understand, contradictory, and open to interpretation, which the IEE regs were not. We were trained on every regulation till we had been through the entire book TWICE, and then examined. You were allowed one retake if you failed, and then you were out of the college, and out of the industry, today, everyone passes

Since the city water is conductive enough to prevent static charge from building up with a non-conductive pipe it's not necessary, but if the pipe were transferring a non-conductive fluid such as oil or gas, absolutely ground both ends of it as the friction between the non-conductive pipe and the flowing non-conductive fluid builds up a static charge.

I’ve dealt with a live gas main entering properties, it’s scary stuff, deffo bond.

I find the fact that this video even needs to exist and many of the comments concerning.

In The Netherlands every home has there own earth-rod connection to the earth. The water inside the pipe may be conductive as well. Therefore inside a bathroom a metal schowerdrain, a metal radiator, warter-taps etc etc are bonded to an earth-wire as well. In older houses with wooden floors, where there is a steel floor-support (in concrete on top of the wooden floor), the steel is earth-wired as well. Is that different form the UK?

What about stainless sinks with these new- fangled electric boiling water taps ? ( double insulated ? or cpc'd wiring?)

Great Video

Interesting video, but I suspect the more complex answer is "it depends". You're only considering the water supply as it enters the building. What if some of the copper is in contact with the earth elsewhere, e.g. a kitchen island? If you can guarantee that it's not, that there is probably more danger of metallic parts becoming live under fault conditions if they were bonded. However, it's also very likely that a boiler (for example) will have all the metallic pipework bonded, so the point is probably moot anyway. If in doubt measure it, and make a decision based on that.

When the main water pipe is metal and the internal pipes are plastic, which is quite common, the few inches of metal pipe into the house needs bonding.

Interesting, I have a blue feed pipe and have earthed internal pipping but was told to also earth stake the internal side of the stopcock with 16mm. This video got me thinking, I had wanted to run a soft copper insulated radiator supply a short distance to the garage in the ground, & the boiler is external oil but the oil supply pipe does already run in the ground !!! This is going to be sleeved in the future but never the less getting wet. & what about old house pipes that in concrete floors. The supply in is overhead line & earth with a main RCD.

How would water hardness affect the resistivity of the water in the pipe? Can it be low enough in a hard water area to connect metal pipes in the house to metal work upstream via the plastic sections with sufficient conducance to restore the threat? Or would it be like limescale brine at that point? (in which case you might have bigger problems anyway).

Once the metal pipework enters a class 1 appliance, like a water heater or central heating boiler, it will likely get bonded anyway via the chassis being earthed.

Joe, what if through various methods such as a gas boiler (cpc from spur), shower (cpc) introduce an earth to the water service through the cpc of the electrical system and where there is no rcd protection should the main water service pipe then be bonded?

Bond it so you don't have an argument when ev installer comes round and does a quick check. 🤣

Good day this is Mike from Amsterdam Holland we got the same problem here but the regulations are you have to bond your tube because when it conduisait it will still conduct the bonding

I had this situation, and inserted a 6 inch length of copper pipe for the equipotential earth bond to keep the water in the pipes at ground potential, since chlorinated water is quite a good conductor. Any better ideas ???

actually, the issue with metal piping in the ground is just the opposite. the earth is NOT a low impedance path to ground, and the bonding network is. so by bonding metal service piping, you are bringing that piping to the same potential as your ground reference. it's not such a big deal with household voltages, but you can get a palpable voltage gradient if distribution voltage starts leaking to ground. in the US, the relevant clause in the code is to the effect of, metal piping must be bonded if there is a possibility of it becoming energized. the usual interpretation of that is that a metal fitting under a sink is not likely to be energized unless it is connected to an appliance - and the appliance will be bonded, so there you have it.

Unless the incoming water supply is demineralised water then it will be conductive (If there were any more minerals in our hard water local supply, it would be supplied in sacks). Regardless of the entry to the house, some of the downstream supply pipework may be metal anyway so there is possibly still a risk. Has there been any investigation as to this being credible? Edit:- I have read some more of the earlier comments regarding water being conductive and I would add this observation based on my experiences in power stations- Demineralised water is non conductive, in fact it is used to cool HV stator windings in large alternators. Insulating pipework lies between the windings and the pumps. However, town water supply is conductive otherwise the electrode boiler (that was used for emergency use in part of the plant) would not work, as it depended on high currents passing through the water within. My personal choice would be to bond anyway, as the IET rules on earthing seem to change rather often.

The argument that the only point at which the metal pipework has a connection to ground potential seems to me to be faulty. Can can imagine all sorts of other scenarios which can lead to the pipework being at ground potential. For example, what if there's a water pipe running underground to a garage, outhouse or garden tap as an example? I can imagine other possibilities. Unless you are going to check the electrical isolation of your pipework to earth with an insulation tester I would recommend bonding the water pipework to ground. I think with anything less than about 10k ohms to earth potential then it has the possibility of carrying a fatal current should something like a PEN failure cause the CPC to go to full line voltage and someone was to touch both. Also, I'm not sure that the high voltage in the vent of an earth current flowing is ever going to lead to a dangerous voltage. Metallic earth returns have very low impedance, and all breakers are meant to trip with gross overloads extremely fast. So the voltage level in the earth is never likely to be very high. 48V is a safe voltage, which is why it was used on telephone systems, and even that would require sustained current of perhaps 150 amperes or more on a typical TN-C-S system, a fault current which would have tripped any domestic MCB extremely quickly. What is a real danger is a break in the combined earth/neutral supply to the property. That is extremely likely to lead to high voltages on the buildings protective earth, and I think you will find that is the main reason why bonding of earthed pipework is so important, as in that case you do not want a very large potential difference between the chassis of a washing machine (say) and your taps and metal sink in the utility room.

In the list (iv) it says central heating do you have to main bond central heating ?

I've always been puzzled about bonding, the reason being, every piece of metal pipework is connected to a CPC, maybe not, but I can't think of the scenario when that's not the case. If you have a gas supply and boiler, the CPC for the boiler connects any metal pipework to earth as would any water heater. A gas boiler connects the CPC to both the water and gas, though I do seem to remember that some boiler manufactures don't do this, I'm not certain of that. When the water companies changed the network to plastic a lot of older properties lost their earthing system all together, as it used to be common practice to use the water pipe as very reliable earth. There are thousands of properties, especially older ones that no longer have a proper earthing system. Why aren't there dead people everywhere due to this issue?? Totally agree that there's no point bonding metallic pipework if the incoming pipes are plastic. Great video and thank you.

My boilers gas pipe will bond the water pipes but this may give a potential difference as it's not as direct as bonding the water pipes directly. This applies to indirect earth connections via an immersion heater, the motorised valves, a waste disposal etc etc. The pipes to radiators or an outside tap may also be contacting the ground at various points so I think pipes should be bonded regardless to assure continuity of earth protection, seems daft not to.

Thank you very much for your videos, I always learn something. I understand the point of not needing to bond a system where the water enters the building in a plastic pipe. But what I struggle with is when that pipe is then connected to copper and buried in the wall to go upstairs for instant. As the walls are connected to the earth (hopefully ;-) ) would this not produce the same earth potential as if the pipe had entered the house in metal. In this scenario would you need to bond the copper pipework?

In the case of an earth fault within a piece of equipment, wouldn’t there be an over current or RCD trip which removes the danger?

Joe, how long to get you in and out of the cabinets? Any pulling lube used?

All instructors should teach via the kitchen sink. Brilliant

some pipes within the house run through the ground. I.E an extension done in copper pipe that was run through the concrete. Therefor is there still a potential within the house?

JOe's analysis of the potential between the neutral at the entrance and the grounding conductor at the transformer is a bit hyperbolic. In the US NEC, there shall be a local grounding conductor in contact with the earth and connected to the ground potential terminal in the breaker box (that is the Green conductor). Bonding to the incoming water supply pipe is one method of creating a grounding connection. Other methods are to connect the earthing conductor to a grounding rod of at least 8 feet (3 meters) driven into the ground, or the attach the conductor to the metal reinforcing rods in the concrete of the foundation. (Ref. NEC-1999 article 250-C). Any non-conductive pipe shall be bridged across from the grounding electrode to the metallic interior pipes, and the exterior grounding water pipe shall be in direct contact with the earth for 3.05 meters. There is another regulation in the IRC abound the distance from the entrance of the metallic pipe to the electrical earthing conductor.

MDPE mains supply pipe fittings could incorporate a moulded Brass metallic earth fitting easily to overcome these issues

I wear my seatbelt with no intention to have a crash so I'd connect it .. And seen as water is conductive what if there is a leak ? Would it then become 0v?

Brilliant video, can you please explain this... If I bond onto a in coming plastic water pipe (the end piece is 15mm copper) but the water will act as earth will it not? No one's mentioned this, the fact the pipes are full of water and conduct electricity! So don't you then get the zero value?

My question is if the municiple side of the pipe is metal somewhere would we still not have conductivity through the water in the pipes into the earth! Thereofre metalic surfaces like water taps would still be a danger?

Even tho the water pipe entry is plastic, the copper pipes in the house come into contact with all sorts and if you measure a resistance to earth, then it may need bonding.

What about gas pipes this too is poly pipe to the house is bonding required or not ? Or …..

How much potential could exist if the plastic was only a couple meters long does not water within the pipehave a low enough restitance to be a path/hazard where it is then connected to the lead incomer just thenother side of the wall. The short piece of plastic isnot acting as a complete isolation from ground? So a potential could exist?

if you are reading from an old code book it may be required in the updated book. if you are reading from a new book then it may have been required and discontinued. the only reasons i can think of why to bond plastic pipes os. 1. a financial kickback the more stuff you have to install the more the industry makes money so maybe grounding wire and clamps cost money and it was done for money. 2. static charge certain contents may cause static build up so it was done to bleed off static. 3. ground loops if there is a section of plastic between 2 metal pipes it is to keep all the metal sections at the same level. 4. plumber was out of pipe clamps so he used an electrical clamp but if that is the case there should be no reason to connect a grounding wire. unless the code book sais that any electrical clamp in the system has to be grounded.

Very well put. I'm of the same mind it makes sense not to connect it but having it connected doesn't seem like it would be that much harm and would be extra insurance in-case of an unintended fault. I'm not thinking poor workmanship that should be the above all standard is that accounts for so many things. I'm thinking water heaters and boilers which are already grounded anyway having a fault or other water loving electric appliances. And well water is non-conductive in a pure state most water has some minerals in it so it wouldn't be truly nonconductive. So does this mean if I have plastic piping going to my tub I can make toast in the bath? Well apart from the GFCI/RCD.

My house has plastic pipes coming in, but I don't know that there aren't any parts of the internal metalwork touching anything conductive that's in the ground... In fact I'm pretty sure that the metal pipe to the oil tank will be connected through the combi-boiler. This old install is bonded and I'm keen to keep it that way

Agree with this video but for some reason I still would prefer to bond it. Plus, isn't water conductive and technically there is a solid H2O conductor running inside the pipe which at some point will be in contact to earth via a pumping station, long shit yes but I don't entirely agree that your copper pipe is entirely insulated because you have plastic pipe. Who knows what's underground a few hundred yards away. I'm not knocking your video, you are correct, just old habits are hard to remove from the older generation. 👍👍👍👍👍

What if the alcathene water service had a leaking joint underground sufficient enough to carry current, then the copper pipe inside the property could have potential??

bonding is there for failure a broken element in your boiler can create the whole thing to come live .. if lightning hits pipework in your loft it needs to go to ground... a modern house were all the pipeworks made out of plastic I will agree.. what your showing needs bonding

I would bond internal metallic pipes because of the risk of they being in contact to the line conductors at some point. That should not happen in a well done electrical installation, but accidents happen and there are bad electricians who will leave wires exposed near metallic pipes.

If a lead water pipe was swapped out for mdpe, would bonding the old still be worth it?

Ive just gone fully electric in my house. The gas is capped off at the meter outside my property (bungalow) there are no exposed service supply pipes exposed above ground level. All metal pipe work is now below floor leve or inside walls. My property has never had any bonding since the house was built in the 60s and ive never had any issues prior to do with fault conditions etc, but ive now been told that my electrical installation cannot be signed off if there is no bonding on both the gas and water. There is no access under the house anymore, so my question is...do I actually need to earth my gas and water if no pipes are exposed above ground level? Am I creating a new problem if I add bonding? I've had the flooring up but there is no way of running 10mm earths from the MET to the incoming Gas & Water supplies. Does this mean my electrical installation is now null & void and I wont receive a cert? Also does my install even need to be earthed taking into consideration the points above. Im having a major headache with this situation so any help or direction would be great appreciated, so I can work out a solution to my problem. Many Thanks.

Would these same regs be applied for an industrial setting?

gas installation pipework also plastic incoming ? The gas regs for this require bonding

In the US it does require bonding. The water in the pipe is not pure, therefore it is conductive. It goes through a metal pipe in the earth somewhere. That is why we ensure all metal pipes are bonded on the US. If metal water pipes are separated by plastic pipe we have to bond both sections. Note to those who would argue with me about the water not being pure: When I say it is not pure I am not talking about how safe it is to drink. Safe to drink is a different metric as compared to purity. Tap water contains minerals. It is not pure H2O until it is distilled. All drinking water and residential tap water has minerals in it.

Yeah. If you earth something that doesn't need to be earthed, ( as you said bedframe), then that creates a dangerous situation, because now if you touch something live, and that earthed object, the current will shoot through you.

What about a metal radiator in the bathroom, or a dual fuel towel rail. RCD protection is this in place. A metal bedrame sits in the middle of a floor. I would bond it for bathroom protection even with RCD.

My thought is the pipe should be bonded as soon as it turns to metal inside the house; Reasons 1-Do you know the whole supply pipe is plastic? 2-i have seen supply pipes where the last foot has been converted to plastic but the rest underground is metal. I know tap water has a quite a high resistance per metre inside plastic but it would still provide a conductive path. 3-What if something is changed in the future and ended up grounding your copper pipes. Better to locate the cable & clamp than do it at a later date.

Assuming the water main in the street is cast iron which is still in quite common use, the water itself will be at zero potential. You may then have a couple of meters of plastic service pipe to the house so by the time the water gets into the copper of the domestic pipework it will not be at zero potential but still quite low. Water is not such a good conductor as copper but still does conduct otherwise why the numerous regulations re installation in potentially damp/wet areas. So if the bonding to the domestic side of the plumbing is no longer required what am I getting wrong.

More vids from under the sink please, this could be a feature

Electricians arguing with each other, loving it 😂😂

And if that pipe feeds an electric shower? And how tight is the mains earth terminal on the shower?

I am not an electrician, but part of my job in an electronics based industry included reviewing technical specifications of the same order of complexity and detail as bs7671, though not usually so long. At best the section as a whole is made AMBIGUOUS by the second line you highlighted. At worst, it lures you into taking the second highlighted part to trump the first. My department would have asked for it to be rewritten to remove the ambiguity, if it was a specification of ours! Electricians take it to mean no need to bond if the water incomer is plastic, but I read it as meaning this: "If you have metal water main coming from the ground but a plastic stopcock or the like interrupts the conductive path, there is no need ALSO to bond the metal part rising from the ground, on the supply side of the break. Only bond the metalwork on the consumers side of the insulating break" The purpose is equipotential bonding. It says so in the heading. If you don't bond the water pipes, etc, you do not HAVE equipotential bonding. My interpretation - that you don't ALSO bond the little bit coming from the ground resolves the apparent conflict. BUT IT NEEDS A REWRITE! In almost every case this piece of pipe at "true ground" will not be more than a few inches long. The context is important, too. It is about EQUIPOTENTIAL bonding. A fridge next to a radiator will be connected to the CPC. It is logical that the radiator too is at the same potential, possibly even if a PEN fault has developed. That is what I take "equipotential" to mean. If you do not bond the pipes then the scenario you kind of dismissed might arise, that a fault - or dodgy workmanship - might cause a potential difference between metal cases of class 1 electrical equipment and nearby radiators, gas pipes, structural steel etc.

The plastic water pipe is only isolated when it is dry, otherwise it is connected to ground through the water within it so any metal pipe connected to this plastic water supply pipe is grounded through the water itself to nearest conductive pipework in the ground. A ground can also be formed through a water leak. If there was a fault applying a voltage to metal pipework connected to a plastic water main there may appear to be no problem until one day there is a leak and the pipework is now effectively grounded creating a return path. This leads to a situation where it could be rather difficult to determine why breakers suddenly start tripping for seemingly no reason (possibly intermittently), people suddenly getting electric shocks in the bath or shower with seemingly no apparent fault and other anomalies. Whereas if the metal pipework was grounded the fault would be apparent straight away and not seem to disappear and then return as well as there being a ground connection that could me tested for current flow which would drastically increase the possibility of diagnosis in a timely manner and genuinely protect peoples lives.

I would leave a earth bond floating around the incoming water on a new rewire just incase there is some major change to the water supply...unlikely but the hassle of not having it around is more... But not connect... and just leave in board but mark it not connected... Depends lots of variables..

I would bond metal pipework, There are that many metal central heating pipes and cold and hot water pipes in contact with the ground that there may be a chance that your plumbing would be in contact with the general mass of earth.

I heard about an EICR recently that had missing earth bonding labelled as a C1. Tennants had to be relocated as the rental agency freaked out. Shocking!

As almost every gas supply is of MDPE one can only assume no bond to gas is required..or is it?

Great vid I’m sure, but things appear and one doesn’t see them appear ( or at least I didn’t ) a flash or a circle ⭕️ maybe pulsating would help the less canny amongst us, ..😊

What if metallic water pipework entered the mass of earth elsewhere in the system after the incomer? I would be bonding then! Think properties with annexes or external water taps… etc.

I'd bond it anyway because you have no way of knowing if the homeowner has installed a metal pipe elsewhere that exits the building, to an outhouse etc. If there was no plastic between that and the incoming metal stopcock then the pipework would then all be at earth potential. You could argue that that shouldn't happen but it's unlikely that a home diyer or plumber would consider that and possibly neither should they have to - it's the electrician's job to ascertain that and plan ahead for it. You mentioned a possibly scenario for not including bonding because it shouldn't be relied upon to prevent danger where other regs have been violated but then surely that is the same for a metal pipe coming in. The earth bonding is there to provide a path back to the panel in the case of a fault which could occur even with a plastic pipe entering, such as driving a nail through a pipe and cable at the same time... I'd say the difference would be that the bed can be moved but the pipework cannot be so should be bonded. You could argue though that the bonding could occur at the most convenient location and not necessarily within the regs distance of entry to the building...

Definitely earth it. I have just discovered my stopcock was live due to fault on Powergrid cable making my earth rod live. Powergrid told me the water pipe should be earthed but the supply pipe installer failed to tell me.

What about fault conditions of say an electric shower? If there was no bonding the supply pipe would be at mains potential.

A PEN fault will promote an alternative return path for neutral current through any extraneous earth connection ie metal water or gas pipes, either from the property affected or as a bypass through a property from an adjacent property on the same supply. Plastic service pipes do at least prevent a dangerous rise in main earth current due to PEN faults. They are more common than you think - check out Team Electrical podcasts 1 and 2 on Diverted Neutral Current. We are not taught to think critically so we expect the DNO head to be whatever it appears to be. Today most service heads are TNC-S and not TNS because somewhere outside the property a repair to the old PILC cable will have made the supply TNC-S. The only exception might be in a rural area where supplies are mostly fed overhead.

Quite often I come across Radio Hams on a TNCS system, but with their own "RF" eath that can be anything from and aditional earth rod of some description driven into the ground to a whole scrap car buried in the garden. Some are insistant that the RF and Mains earths have to be isolated from each other, some ask why a multimeter shows a voltage difference between them, and some will actualy allow a bonding connection between them. I always suggest that the RF earth can be improved by linking them and quote ohms law :)

I would still bond if it’s an existing installation or pipework. Somewhere on the pipework could be bonded to earth but not the rest of the cpc

If there is any earth leakage current wouldnt the RCD trip ? (Residual currect device.)

How about this scenario, “a non extraneous” water pipe with an insulating section at its point of entry doesn’t require a main equipotential bond. So what about when this turns internally into a copper water pipe installation, then this copper pipe is installed into a metallic boiler manifold. Then this manifold connects to the extraneous gas pipe work (with a metallic section at its point of entry) surely now this “common” copper pipe work is now deemed to be extraneous???? And how the hell do you successfully perform a 22K test on “commoned up” gas and water copper pipe work installation? 🤷‍♂️