Earth bonding to boiler pipes

[CLB]

Hi, I came across an install where the equipotential bonding to the pipes feeding the boiler had been taken from the spur providing the power to it. It was run as a separate 10mm earth wire from the fuse box (connected to the earth terminal inside) and cable tied to the power flex going to the boiler. I checked the equipotential bonding from the MET to the gas/water service pipes and they were in place and correct. I'm wondering why this additional earth wire was run to the boiler pipes in the way that it has been and whether it represents a danger in the case of a live to earth fault as it seems to be a part of the electrical wiring installation and not as part of the equipotential bonding. At the boiler end it is daisy chained across the pipes.

 

[telectrix]

not very clear. are you saying that the 10mm is connected in the FCU?

 

[ezzzekiel]

thats what it sounded like.
providing main bonds are ran to gas/water then your work is complete, however i believe it is still a gas regulation that boilers be cross bonded which is prob required as heating engineers arent required to check main bonds.

 

[CLB]

not very clear. are you saying that the 10mm is connected in the FCU?

Apologies. It has been run from the earth terminal in the fused spur feeding the boiler, out through the bottom of the flush mounted backbox and strapped to the flex going to the boiler, then it attached to the pipes using BS951 earth clamps.

 

[telectrix]

remove it, then do a continuity test from MET to boiler pipes. if you get a decent reading then chuck the 10mm in your scrap box.

edit: or is it the other way round, the 10mm supplying the E to the FCU?

 

[paul_h]

The spec I have to wire my combis too says that i should run a 10mm green/yellow to the flow and cross bound to the return. Can't understand why tho as after 600mm from the boiler these pipes turn to plastic lol

 

[iconnect]

The spec I have to wire my combis too says that i should run a 10mm green/yellow to the flow and cross bound to the return. Can't understand why tho as after 600mm from the boiler these pipes turn to plastic lol

Never heard of just flow to return on council they always wanted flow,return,hot,cold,gas

 

[BillyH]

thats what it sounded like.
providing main bonds are ran to gas/water then your work is complete, however i believe it is still a gas regulation that boilers be cross bonded which is prob required as heating engineers arent required to check main bonds.

How can it be a gas reg when it's electrical work?

 

[ezzzekiel]

dont know to be honest, just know we were pulled into a meeting for not cross bonding at boilers apparently gas manager insisted upon it as its within thier regs - i did try to protest that if we deemed all bonding satisfactory then they could cross bond the boilers if they wished - but lost, so sparks have to do it.

 

[iconnect]

Council contrats are full of not in the regs

 

[trev]

Still not very clear what the OP means. Are you saying that there's a cable going to the gas pipe within 600mm of the meter then another coming from the spur to the boiler pipes?