Is it necessary to earth a hot water pipe?

[graham365]

Might seem an odd question, but I'm fitting a new kitchen at the moment, and have discovered beneath the old sink that:

a) the mains earth is connected to the cold water pipe (feeding directly into the ground);
b) there's an earth wire running from the cold water pipe to the hot water pipe; and
c) there's another earth wire running from the hot water pipe to a clamp beneath the sink.

I'd have thought just a) was OK; but I'm checking here because this has me both confused and slightly worried. Do I just need to connect the earth wire(s) to the cold water, or to the hot and/or sink as well?

Cheers.
g

 

[breezer]

connect it as it is now, try a search for bonding for more info

 

[securespark]

Bonding to sink is uneccesary. See here

//www.diynot.com/forums/viewtopic.php?t=10512

 

[ban-all-sheds]

a) the mains earth is connected to the cold water pipe (feeding directly into the ground)

1)Is that where the main water pipe enters the building?

2) When you say that the mains earth is connected to it, do you mean that that is where the earth from your CU is attached, or that there is an earth cable running from the pipe to the main earthing terminal of your incoming electricity supply?

 

[graham365]

a) the mains earth is connected to the cold water pipe (feeding directly into the ground)

1)Is that where the main water pipe enters the building?

Yes.

2) When you say that the mains earth is connected to it, do you mean that that is where the earth from your CU is attached, or that there is an earth cable running from the pipe to the main earthing terminal of your incoming electricity supply?

Not sure. The earth cable (very thick, lots of wires, unlike any other earth cable I've seen in the normal run of things) runs from inside the kitchen wall directly to the cold water pipe which enters the building (though it's not copper when it enters the building, more like rubber, changing to copper at the stop tap, then the earth cable is connected just above the stop tap). It's fastened with one of those metal clip things which I;ve only ever seen used to connect wires to pipes.

Incidentally, what happens if the hot water pipe isn't earthed? I'm asking because I've seen other posts in which it's suggested the gas pipe should be earthed (bonded?) and I'm pretty sure ours hasn't been ever since we moved in about 20 years ago.

Cheers.

 

[ban-all-sheds]

2) When you say that the mains earth is connected to it, do you mean that that is where the earth from your CU is attached, or that there is an earth cable running from the pipe to the main earthing terminal of your incoming electricity supply?

Not sure. The earth cable (very thick, lots of wires, unlike any other earth cable I've seen in the normal run of things)

Sounds like a fairly normal main earth cable to me.

runs from inside the kitchen wall directly to the cold water pipe which enters the building (though it's not copper when it enters the building, more like rubber, changing to copper at the stop tap, then the earth cable is connected just above the stop tap). It's fastened with one of those metal clip things which I;ve only ever seen used to connect wires to pipes.

So the incoming water pipe is non-metallic, and there's an earth cable attached just after where it becomes a metal pipe. Where is the other end of the cable connected?

Incidentally, what happens if the hot water pipe isn't earthed? I'm asking because I've seen other posts in which it's suggested the gas pipe should be earthed (bonded?) and I'm pretty sure ours hasn't been ever since we moved in about 20 years ago.

Cheers.

If your gas pipe is metal, then it should be earthed. You do not need to bond hot water pipes in the kitchen, or kitchen sinks.

 

[graham365]

So the incoming water pipe is non-metallic, and there's an earth cable attached just after where it becomes a metal pipe. Where is the other end of the cable connected?

I don't know -- it just runs from the cold water pipe and disappears (up) into the outside wall. I assumed it was in some way connected to the mains from there.

Thanks for your help, btw.

 

[kendor]

2) When you say that the mains earth is connected to it, do you mean that that is where the earth from your CU is attached, or that there is an earth cable running from the pipe to the main earthing terminal of your incoming electricity supply?

Not sure. The earth cable (very thick, lots of wires, unlike any other earth cable I've seen in the normal run of things)

Sounds like a fairly normal main earth cable to me.

runs from inside the kitchen wall directly to the cold water pipe which enters the building (though it's not copper when it enters the building, more like rubber, changing to copper at the stop tap, then the earth cable is connected just above the stop tap). It's fastened with one of those metal clip things which I;ve only ever seen used to connect wires to pipes.

So the incoming water pipe is non-metallic, and there's an earth cable attached just after where it becomes a metal pipe. Where is the other end of the cable connected?

Incidentally, what happens if the hot water pipe isn't earthed? I'm asking because I've seen other posts in which it's suggested the gas pipe should be earthed (bonded?) and I'm pretty sure ours hasn't been ever since we moved in about 20 years ago.

Cheers.

If your gas pipe is metal, then it should be earthed. You do not need to bond hot water pipes in the kitchen, or kitchen sinks.

As long as the reading is ok!

 

[ban-all-sheds]

So the incoming water pipe is non-metallic, and there's an earth cable attached just after where it becomes a metal pipe. Where is the other end of the cable connected?

I don't know -- it just runs from the cold water pipe and disappears (up) into the outside wall. I assumed it was in some way connected to the mains from there.

Thanks for your help, btw.

Could you take a look at your where your electrical supply enters the house, and see what cables are attached to the Main Earthing Terminal?

 

[securespark]

2) When you say that the mains earth is connected to it, do you mean that that is where the earth from your CU is attached, or that there is an earth cable running from the pipe to the main earthing terminal of your incoming electricity supply?

Not sure. The earth cable (very thick, lots of wires, unlike any other earth cable I've seen in the normal run of things)

Sounds like a fairly normal main earth cable to me.

runs from inside the kitchen wall directly to the cold water pipe which enters the building (though it's not copper when it enters the building, more like rubber, changing to copper at the stop tap, then the earth cable is connected just above the stop tap). It's fastened with one of those metal clip things which I;ve only ever seen used to connect wires to pipes.

So the incoming water pipe is non-metallic, and there's an earth cable attached just after where it becomes a metal pipe. Where is the other end of the cable connected?

Incidentally, what happens if the hot water pipe isn't earthed? I'm asking because I've seen other posts in which it's suggested the gas pipe should be earthed (bonded?) and I'm pretty sure ours hasn't been ever since we moved in about 20 years ago.

Cheers.

If your gas pipe is metal, then it should be earthed. You do not need to bond hot water pipes in the kitchen, or kitchen sinks.

As long as the reading is ok!

Ken

See newly released NIC book "Snags & solutions - earthing & bonding" and you will see that they are adamant that bonding to a sink is NOT required. (Snag 29).

 

[graham365]

Could you take a look at your where your electrical supply enters the house, and see what cables are attached to the Main Earthing Terminal?

I've had a look. I'm not sure what a main earthing terminal is; but I have discovered that the gas pipe *is* earthed, which is a relief. Basically, there's a red and black wire running from the ground to the meter, then on to the fuse box. The earth seems to come from the wall (presumably originally from the cold water pipe I mentioned above), then to the fuse box.

 

[plugwash]

how many single earth wires (e.g. not part of a cable) enter the CU

if its just the ones you mention (e.g. one to the water and one to the gas) it seems you don't have a proper earth setup

if this is the case get a qualified electrician in NOW

 

[securespark]

Let's put your mind at rest: post us a piccy of your incoming supply.

 

[ban-all-sheds]

Sounds like it might be what I was afraid of, which is why I asked him to look - the installation is earthed (or not ) via the water main.

 

[graham365]

Let's put your mind at rest: post us a piccy of your incoming supply.

OK, here's a couple of pics. You'll know better than I what they show, but basically the top one is an extension of the bottom one.

As far as I can make out, the top pic shows the fuse box, with an earth wire coming out left to the gas pipe, and live and neutral (presumably) and earth coming down to the board at the bottom.

The bottom pic shows the live and neutral with the meter (can someone tell me what the grey thing is beneath the meter?); and then an earth cable I'd not noticed before also entering the grey box. The earth wire coming from the fuse box was the one I originally thought went into the wall; but maybe it goes into that grey box?

Sorry for my ignorance. That's one reason I'm here.