Another electrical question -pipe bonding...

[HotJambalaya]

So having finally finished my build and getting the sparky in, he says, where's the earthing for the water mains, cue, errrrrrrrrr moment...

So I appear to have 2 mains coming into the flat, one from the communal pipes that seems to do bathrooms, though it is also connected to preeeeeety much everything else. There is also another one, that seems to come up from the street, straight into the kitchen, and does the sink, and dishwasher. I'm a little unclear if it does the boiler too.

Which is supposed to be bonded? Either? Both?

I'm currently running a wire from the fusebox to the bathroom one, just because it saves me ripping out half the kitchen which I just put in, but if needs be.....

[DrDeAtH]

All metal incoming pipework is to be bonded back to the main earthing terminal at either the consumer unit or service intake, whichever is easier.

So, gas, water,oil all need bonding. 10mm cable size.

[Gingerbread Man]

2 water mains is a bit queer. Are you sure one doesn't go to an external tap or similar? I'd try turning one off and seeing what happens, what works what doesn't.

[DrDeAtH]

Some places do have 2 mains. I have worked in a few that have. But yes, it's uncommon.

[HotJambalaya]

Gingerbread Man said:

2 water mains is a bit queer. Are you sure one doesn't go to an external tap or similar? I'd try turning one off and seeing what happens, what works what doesn't.

I might be getting my terminology a bit wrong, one of them is water coming straight in from the street, and that's the only place I can turn it off.

There's another one Inbetween the two bathrooms, I had to change the shut off on that and to do that we had to turn off water for the whole block.

There actually appeared to be a third one that neither of the other two effected, and was a feed into the old boiler. Shutting off the mains in the street, and the one in the bathrooms didn't stop that one either. As we found out when we cut it...

There's no external tap or anything, it's a 4th floor flat

[Rickyy]

Gingerbread Man said:

2 water mains is a bit queer. Are you sure one doesn't go to an external tap or similar? I'd try turning one off and seeing what happens, what works what doesn't.

One is usually a cold main and the other will be a tank fed supply.

My old flat had just the kitchen sink off the mains and everything else was tank fed.

[HotJambalaya]

Rickyy said:

One is usually a cold main and the other will be a tank fed supply.

My old flat had just the kitchen sink off the mains and everything else was tank fed.

Yep thats what this is

[Gingerbread Man]

Rickyy said:

Gingerbread Man said:

2 water mains is a bit queer. Are you sure one doesn't go to an external tap or similar? I'd try turning one off and seeing what happens, what works what doesn't.

One is usually a cold main and the other will be a tank fed supply.

My old flat had just the kitchen sink off the mains and everything else was tank fed.

Good point.
I read into the two water mains too literary as two incomming street mains. I've left my days of loft tank water behind.
Sometimes flats have a communal loft with many a tank. Typically never labeled.