boiler cross bonding

[asc]

I still see a lot of this on new boiler installs. Can anyone tell me when this was no longer a requirement? was it 15th to 16th some time in the 90s?

 

[ricicle]

It never was a requirement under BS7671 (unless the boiler was in a location that required supplementary bonding.)
Supplementary bonding is no longer usually required under the 17th edition in a domestic set-up when other measures are met (disconnection times, RCD and main protective bonding)

Boiler installers will try and tell you otherwise.

 

[bernardgreen]

It amuses me to see an installer carefully and neatly cross bonding the pipes to the boiler when all the pipes are securely fastened to the gland plate in the boiler and thus already electrically "bonded" to each other.

 

[JohnW2]

It never was a requirement under BS7671 (unless the boiler was in a location that required supplementary bonding.)
Supplementary bonding is no longer usually required under the 17th edition in a domestic set-up when other measures are met (disconnection times, RCD and main protective bonding).

I'm not sure whether there are any boiler designs which leave any doubt that all of the attached pipework is effectively electrically bonded together (by plumbing connections) - but, if there are, am I right in thinking that 'cross-bonding' at the boiler would then be required in order to satisfy condition (iii) in 701.415.2 for omission of supplementary bonding in bathrooms in the premises?

Kind Regards, John.

 

[ricicle]

I'm not sure whether there are any boiler designs which leave any doubt that all of the attached pipework is effectively electrically bonded together (by plumbing connections) - but, if there are, am I right in thinking that 'cross-bonding' at the boiler would then be required in order to satisfy condition (iii) in 701.415.2 for omission of supplementary bonding in bathrooms in the premises?

Kind Regards, John.

Good point - it first must be ensured that all the pipes are electrically connected together by the gland plate before SB can be omitted.

 

[JohnW2]

Good point - it first must be ensured that all the pipes are electrically connected together by the gland plate before SB can be omitted.

Indeed. Needless to say, what I was mainly thinking about was PTFE tape. With MI/FI connections, it is sometimes used so generously that I don't think that electrical continuity can necessarily be assumed. Furthermore, although one really shouldn't use PTFE tape at all with compression joints, some plumbers seem not only to use it but, again, very generously - leaving similar doubts in my mind.

Kind Regards, John.