A report on a house I'm buying says there "is no evidence of
equipotential earth bonding" of the incoming gas supply to the boiler.
I have also been told it needs an electrician to correct this.


What exactly does equipotential earth bonding mean, and how important
is it to have it?

wrote in message
oups.com...
A report on a house I'm buying says there "is no evidence of
equipotential earth bonding" of the incoming gas supply to the boiler.
I have also been told it needs an electrician to correct this.


What exactly does equipotential earth bonding mean, and how important
is it to have it?


It is a cross earthling of metal objects (pipes in this example)

At the boiler, all the pipes should be connected to each other with earth
cables and clamps, then at lease a 10mm cable sent back to the main earth
terminal (in or near the consumer unit). By what you have posted, it looks
like the gas pipe has been left out of this (It is very easy to rectify with
an earth clamp and a piece of 10mm earth cable).

Is for how important, it is required by the regs, but hasn't always been.

Sparks...

wrote:

What exactly does equipotential earth bonding mean, and how important
is it to have it?

http://www.diyfaq.org.uk/electrical/....html#earthing

--
Andy

wrote:

A report on a house I'm buying says there "is no evidence of
equipotential earth bonding" of the incoming gas supply to the boiler.
I have also been told it needs an electrician to correct this.


What exactly does equipotential earth bonding mean, and how important
is it to have it?

Its trivial, and is not needed on existing house wiring. If you rewired
the place, you would be required to put it in as part of the rewire,
but not otherwise. Its safety value is miniscule, but not quite zero.
It could save your life, but is unlikely to in the extreme. The
majority of houses today dont have equi. Your stairs are 100s of times
more risk, and ditto many other things.

Anyone that tells you you need an electrician to correct it is wrong on
2 counts. First there is no need or requirement to fit it, 2nd its an
easy diy job.

Surveyors use the presence or absence of equipotential bonding as a
quick marker of how old the wiring is. If theres no equi, they dont
know what age the wiring is, but it wont have been done recently.


NT

"Sparks" wrote in message
.. .
wrote in message
oups.com...
A report on a house I'm buying says there "is no evidence of
equipotential earth bonding" of the incoming gas supply to the boiler.
I have also been told it needs an electrician to correct this.


What exactly does equipotential earth bonding mean, and how important
is it to have it?


It is a cross earthling of metal objects (pipes in this example)

At the boiler, all the pipes should be connected to each other with earth
cables and clamps, then at lease a 10mm cable sent back to the main earth
terminal (in or near the consumer unit). By what you have posted, it looks
like the gas pipe has been left out of this (It is very easy to rectify
with an earth clamp and a piece of 10mm earth cable).

Is for how important, it is required by the regs, but hasn't always been.

Sparks...


Out of interest what reqstates the above??

wrote:
Anyone that tells you you need an electrician to correct it is wrong on
2 counts. First there is no need or requirement to fit it, 2nd its an
easy diy job.

But can you DIY it under Part P without a building notice?

Richard Conway wrote:

But can you DIY it under Part P without a building notice?

Yes, it's not notifiable work.

--
Andy

"Stephen Dawson" wrote in message
...

"Sparks" wrote in message
.. .
wrote in message
oups.com...
A report on a house I'm buying says there "is no evidence of
equipotential earth bonding" of the incoming gas supply to the boiler.
I have also been told it needs an electrician to correct this.


What exactly does equipotential earth bonding mean, and how important
is it to have it?


It is a cross earthling of metal objects (pipes in this example)

At the boiler, all the pipes should be connected to each other with earth
cables and clamps, then at lease a 10mm cable sent back to the main earth
terminal (in or near the consumer unit). By what you have posted, it
looks like the gas pipe has been left out of this (It is very easy to
rectify with an earth clamp and a piece of 10mm earth cable).

Is for how important, it is required by the regs, but hasn't always been.

Sparks...


Out of interest what reqstates the above??

547-02 covers most of it including table 54H. On Site Guide fills in the
gaps

"Bob Watkinson" wrote in message
...

"Stephen Dawson" wrote in message
...

"Sparks" wrote in message
.. .
wrote in message
oups.com...
A report on a house I'm buying says there "is no evidence of
equipotential earth bonding" of the incoming gas supply to the boiler.
I have also been told it needs an electrician to correct this.


What exactly does equipotential earth bonding mean, and how important
is it to have it?


It is a cross earthling of metal objects (pipes in this example)

At the boiler, all the pipes should be connected to each other with
earth cables and clamps, then at lease a 10mm cable sent back to the
main earth terminal (in or near the consumer unit). By what you have
posted, it looks like the gas pipe has been left out of this (It is very
easy to rectify with an earth clamp and a piece of 10mm earth cable).

Is for how important, it is required by the regs, but hasn't always
been.

Sparks...


Out of interest what reqstates the above??

547-02 covers most of it including table 54H. On Site Guide fills in the
gaps


Can I refer you all to OSG (brown Cover) Page 25 Section 4.5, no mention
there of the need for supplementary bonding of a boiler unless it is in a
special location.

What I beleive from the OP is that the main bond is missing and should be
connected within 600mm o the entry of the gas supply to the property.

The is no reason or reg that says, that I am aware of, that you must cross
bond a boiler.

If some one can point me to it the I will stand corrected.

"Stephen Dawson" wrote in message
...

"Bob Watkinson" wrote in message
...

"Stephen Dawson" wrote in message
...

"Sparks" wrote in message
.. .
wrote in message
oups.com...
A report on a house I'm buying says there "is no evidence of
equipotential earth bonding" of the incoming gas supply to the boiler.
I have also been told it needs an electrician to correct this.


What exactly does equipotential earth bonding mean, and how important
is it to have it?


It is a cross earthling of metal objects (pipes in this example)

At the boiler, all the pipes should be connected to each other with
earth cables and clamps, then at lease a 10mm cable sent back to the
main earth terminal (in or near the consumer unit). By what you have
posted, it looks like the gas pipe has been left out of this (It is
very easy to rectify with an earth clamp and a piece of 10mm earth
cable).

Is for how important, it is required by the regs, but hasn't always
been.

Sparks...


Out of interest what reqstates the above??

547-02 covers most of it including table 54H. On Site Guide fills in the
gaps


Can I refer you all to OSG (brown Cover) Page 25 Section 4.5, no mention
there of the need for supplementary bonding of a boiler unless it is in a
special location.

What I beleive from the OP is that the main bond is missing and should be
connected within 600mm o the entry of the gas supply to the property.

The is no reason or reg that says, that I am aware of, that you must cross
bond a boiler.

If some one can point me to it the I will stand corrected.

I'm not with you. 547-02 is the reg that covers it. There is a great deal in
the regs that don't appear in the OSG hence the difference in the size of
the two volumes.

"Bob Watkinson" wrote in message
...

"Stephen Dawson" wrote in message
...

"Bob Watkinson" wrote in message
...

"Stephen Dawson" wrote in message
...

"Sparks" wrote in message
.. .
wrote in message
oups.com...
A report on a house I'm buying says there "is no evidence of
equipotential earth bonding" of the incoming gas supply to the
boiler.
I have also been told it needs an electrician to correct this.


What exactly does equipotential earth bonding mean, and how important
is it to have it?


It is a cross earthling of metal objects (pipes in this example)

At the boiler, all the pipes should be connected to each other with
earth cables and clamps, then at lease a 10mm cable sent back to the
main earth terminal (in or near the consumer unit). By what you have
posted, it looks like the gas pipe has been left out of this (It is
very easy to rectify with an earth clamp and a piece of 10mm earth
cable).

Is for how important, it is required by the regs, but hasn't always
been.

Sparks...


Out of interest what reqstates the above??

547-02 covers most of it including table 54H. On Site Guide fills in the
gaps


Can I refer you all to OSG (brown Cover) Page 25 Section 4.5, no mention
there of the need for supplementary bonding of a boiler unless it is in a
special location.

What I beleive from the OP is that the main bond is missing and should be
connected within 600mm o the entry of the gas supply to the property.

The is no reason or reg that says, that I am aware of, that you must
cross bond a boiler.

If some one can point me to it the I will stand corrected.

I'm not with you. 547-02 is the reg that covers it. There is a great deal
in the regs that don't appear in the OSG hence the difference in the size
of the two volumes.


No it does not 547-02 covers main equipotentil bonding condustors, not
cross bonding at boilers. A with regard to a great deal in the regs I have
BS7671 in front of me, as is the OSG and all the guidance notes plus other
forms of reference.

So at the moment I am still of the opinion you do not need to bond the
boiler.

Stephen Dawson wrote:

No it does not 547-02 covers main equipotentil bonding condustors, not
cross bonding at boilers. A with regard to a great deal in the regs I have
BS7671 in front of me, as is the OSG and all the guidance notes plus other
forms of reference.

So at the moment I am still of the opinion you do not need to bond the
boiler.

Interesting one this. The more relevant regulation is actually
413-02-02 which contains a (non-exhaustive) list of
extraneous-conductive-parts which should be main-bonded. This does
include "central heating and air conditioning systems." However
remember the definition of "extraneous-conductive-part" i.e. a
conductive part which is not part of the electrical installation and
which is liable to introduce a potential (generally earth potential).

Now a boiler is /inter alia/ an electrical appliance so cannot be
"extraneous" - it's an exposed conductive part and needs to be earthed
though its CPC (obviously). If installed in a bathroom (or other
special location) it would need to be included in the supplementary
bonding. Otherwise the boiler /per se/ surely doesn't need bonding.

Whether other parts of the CH system need main bonding is a moot point.
If the system involved pipework coming in from outside the
equipotential zone (e.g. district heating) then that would certainly
need main-bonding. Otherwise, for a regular domestic CH system, there's
not really anything to import a potential, so it's outside the scope of
the definition. Or perhaps you can argue that the main water bond does
the job - especially as it is common practice to supplementarily
cross-bond every pipe in sight near a boiler or in an airing cupboard.
As has been said, this is not really discussed in the OSG, or the EGBR
(other than re-stating the list from 413-02-02), and if it was seen as
an 'issue' it would be.

Interesting to note that a similar debate appears to have raged on the
IEE Web forum earlier this year:
http://www.iee.org/Forums/forum/messageview.cfm?catid=205&threadid=4618&STARTPAGE= 1&FTVAR_FORUMVIEWTMP=Linear

I wonder what the NICEIC technical manual has to say about this. Anyone
out there got a copy?

--
Andy

On Tue, 15 Nov 2005 17:44:46 GMT someone who may be "Stephen Dawson"
wrote this:-

So at the moment I am still of the opinion you do not need to bond the
boiler.

Going back to the original posting, 'A report on a house I'm buying
says there "is no evidence of equipotential earth bonding" of the
incoming gas supply to the boiler.' and that is what the subsequent
discussion has been about. I think posters have been saying much the
same thing, but in different ways and this is where the confusion
arises.

The flow and return pipes of the heating system should certainly be
bonded, along with the gas pipe by the meter, under regulations
given earlier. If the boiler is joined to these pipes by reliable
metal to metal contact then it is bonded, just like the radiators.
There is normally no need to attach a bonding conductor to the
boiler itself. As an item of fixed equipment it also has the
protective conductor from the supply connected to the metalwork of
the boiler, just like a built in oven.

Someone asked if this is important. Plumbers are occasionally killed
by unearthed pipework that has become live for some reason, such as
the heat from a heating pipe slowly melting the insulation of a
cable laid over it without protection.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

Andy Wade wrote:
wrote:

What exactly does equipotential earth bonding mean, and how important
is it to have it?

http://www.diyfaq.org.uk/electrical/....html#earthing

The FAQ says not to rely on the pipes for a metal bath, so how is one
supposed to make a connection? There appears to be no tag of any sort
for this purpose.

Is it OK to rely on the pipes to make the connection for a towel rail?
I'll need to jumper around some plastic push fit.

MBQ

On 16 Nov 2005 06:04:10 -0800 someone who may be
wrote this:-

http://www.diyfaq.org.uk/electrical/....html#earthing

The FAQ says not to rely on the pipes for a metal bath, so how is one
supposed to make a connection?

Drill a hole in a suitable place, like one of the feet. Tap the
hole. Insert bolt.

Is it OK to rely on the pipes to make the connection for a towel rail?

Does it have an electric heating element?


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

David Hansen wrote:
On 16 Nov 2005 06:04:10 -0800 someone who may be
wrote this:-

http://www.diyfaq.org.uk/electrical/....html#earthing

The FAQ says not to rely on the pipes for a metal bath, so how is one
supposed to make a connection?

Drill a hole in a suitable place, like one of the feet. Tap the
hole. Insert bolt.

Plastic feet ;-( only the bath is metal and I'm not drilling a hole in
that!



Is it OK to rely on the pipes to make the connection for a towel rail?

Does it have an electric heating element?

No, it's part of the central heating, hence the reference to pipes.

It's connected by pushfit so I assume I need to jumper around those but
I can do that unobtusively if I can rely on the last few inches of
copper pipe. Hence my question if you shouldn't rely on the pipes to a
bath, how can you rely on the pipes to anything else?

MBQ

On 16 Nov 2005 08:28:28 -0800 someone who may be
wrote this:-

Plastic feet ;-( only the bath is metal and I'm not drilling a hole in
that!

Does the bath have a suitable unobtrusive place to drill a hole?

Is it OK to rely on the pipes to make the connection for a towel rail?

Does it have an electric heating element?

No, it's part of the central heating, hence the reference to pipes.

Some towel rails have an electric heating element, in addition to
being heated by water from the boiler. As it doesn't then I would
treat it like a radiator, supplementary bonding to the flow and
return pipes nearby is usually adequate. I say usually as I can't
remotely measure things in the room.

Hence my question if you shouldn't rely on the pipes to a
bath, how can you rely on the pipes to anything else?

Washers underneath the taps may well insulate the pipes/taps from
the bath and thus the bath would be unearthed while the pipes are,
which would be potentially dangerous. With a towel rail or radiator
there will normally be reliable metal to metal contact between the
fitting and the flow/return pipes. If plumbing joints could not be
relied upon then every length of pipe and radiator would end up
being bonded, which would be ridiculous (but a good source of income
for some).

Note, all the above relates to "real" plumbing systems with metal
pipes and proper joints. Pushfit "joints" and/or plastic pipes make
things more interesting, more difficult in some ways, easier in
others.



--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

Stephen Dawson wrote:
"Bob Watkinson" wrote in message
...

"Stephen Dawson" wrote in message
...

"Bob Watkinson" wrote in message
...

"Stephen Dawson" wrote in message
...

"Sparks" wrote in message
.. .
wrote in message
oups.com...
A report on a house I'm buying says there "is no evidence of
equipotential earth bonding" of the incoming gas supply to the
boiler.
I have also been told it needs an electrician to correct this.


What exactly does equipotential earth bonding mean, and how important
is it to have it?


It is a cross earthling of metal objects (pipes in this example)

At the boiler, all the pipes should be connected to each other with
earth cables and clamps, then at lease a 10mm cable sent back to the
main earth terminal (in or near the consumer unit). By what you have
posted, it looks like the gas pipe has been left out of this (It is
very easy to rectify with an earth clamp and a piece of 10mm earth
cable).

Is for how important, it is required by the regs, but hasn't always
been.

Sparks...


Out of interest what reqstates the above??

547-02 covers most of it including table 54H. On Site Guide fills in the
gaps


Can I refer you all to OSG (brown Cover) Page 25 Section 4.5, no mention
there of the need for supplementary bonding of a boiler unless it is in a
special location.

What I beleive from the OP is that the main bond is missing and should be
connected within 600mm o the entry of the gas supply to the property.

The is no reason or reg that says, that I am aware of, that you must
cross bond a boiler.

If some one can point me to it the I will stand corrected.

I'm not with you. 547-02 is the reg that covers it. There is a great deal
in the regs that don't appear in the OSG hence the difference in the size
of the two volumes.


No it does not 547-02 covers main equipotentil bonding condustors, not
cross bonding at boilers. A with regard to a great deal in the regs I have
BS7671 in front of me, as is the OSG and all the guidance notes plus other
forms of reference.

So at the moment I am still of the opinion you do not need to bond the
boiler.

Ok if you say so. On you go then.