Electrical issues in potential new house

After having an offer accepted on a house we had had a house survey done which was something between the typical mortgage survey and a structural survey. 

He found electrical issues with the house as well as a few other things - but overall the structure was sound.  One thing he talked about at the end of the survey was getting an electrical update...here's what he said the problem was (hoping someone has a clue that can help us determine if we need to do further investigations):

"A supply of electricity is available to the property.  This was wired on a 13-amp ring main circuit but I believe installed before 1991.  It is now considered to be out of date in indeed the earth bonding in relation to continuous earthing bonding from the electrical installation in the kitchen for the boiler and elsewhere should have been taken back to the consumer fuse unit and this has not been undertaken.  I believe it does not reach appropriate safety standards and indeed the installation and consumer fuse unit is somewhat dated and perhaps a leakage detector should have been introduced into the electrical installation with a more modern fuse unit incorporating this RCD connection."

Any thoughts?

My first thought on reading that report is "3-day wonder."       That's a somewhat disparaging term we've been using in technical discussions to describe home inspectors who have gone on a 3-day course to "qualify" them to inspect domestic electrical systems when they had almost zero electrical knowledge beforehand.   No doubt they're trying their best, but they simply cannot gain enough expertise in so short a time to make a reliable, informed report.

This report certainly reads like many others I've seen from similar sources, as though the inspector has just seized upon a few key points which were covered in the brief course.  It's pretty muddled, certainly not written by someone in the electrical field, and after four or five slow reads I think I've worked out what he's trying to say, but I'm not absolutely certain. 

Analyzing his comments piece by piece:

A supply of electricity is available to the property.  This was wired on a 13-amp ring main circuit but I believe installed before 1991. 

The ring circuit should be 30 or 32 amps.  The sockets on it are 13 amps, which I assume it was he meant.   Ring circuits have been a standard arrangement in the U.K. for over 50 years, although not supplying the whole house.

The fact that wiring was installed prior to 1991 is really of no consequence.  Whether it was installed properly and whether it is in good condition is much more important than whether it was installed in 2001 or 1981.   Much older wiring (1940s/1950s) which used VIR (Vulcanized India Rubber) cable needs careful examination, since the rubber insulation can have perished badly over time, but PVC-insulated cables installed since the 1960s don't deteriorate with age in the same way. 

There seems to be quite a growing tendency to dismiss anything more than a few years old as being out of date and in need of replacement, when in fact it might be perfectly acceptable.   

It is now considered to be out of date in indeed the earth bonding in relation to continuous earthing bonding from the electrical installation in the kitchen for the boiler and elsewhere should have been taken back to the consumer fuse unit and this has not been undertaken. 

This part isn't very clear at all. 

You should have an earth bonding cable which runs from the distribution panel (fuse box) to the water supply pipe where it enters the house.  The connection is typically made with a clamp just above the main stopcock where the pipe comes through the floor from underground.  You may then have what is called supplementary equipotential bonding between various other pipes, creating a metallic path between hot & cold feed pipes to a sink, between the various pipes connecting to the boiler, and so on.  These supplementary bonds are not normally extended back to the distribution panel, nor is there any such requirement in the wiring regulations.

So is he trying to say that the main earth bonding to the water system is missing?  Or is he looking at the supplementary bonding conductors and mistakenly thinking that they should have been extended back to the panel as well?    I'm not sure. 

I believe it does not reach appropriate safety standards and indeed the installation and consumer fuse unit is somewhat dated and perhaps a leakage detector should have been introduced into the electrical installation with a more modern fuse unit incorporating this RCD connection.

It sounds as though you have no ELCB or RCD, but except for houses in rural areas that was pretty much the norm at one time.   The IEE Wiring Regulations -- which are not mandatory but are the generally accepted standard for wiring in Britain -- have gradually extended the scope of RCD protection over the years.   I suspect this might be where he is getting his assumption that the installation predates 1991 or thereabouts.

The 16th edition of the rules which was in force from 1992 specified that RCD (earth leakage) protection should be provided on any socket "likely" to be used for supplying equipment outdoors (and the interpretation of that rather vague term "likely" has been the subject of much debate).   The new 17th edition of the regulations has just come into force from the first of this month, and now demands that all standard 13-amp sockets provided for general purpose use should have RCD protection. 

The standards are not retroactive, however, and on matters such as this are very much open to a degree of subjective analysis.   The RCD certainly provides an added level of protection, but that doesn't automatically mean that an installation without one is unsafe (in the same way that you might look upon antilock brakes on a new car as an added safety feature, but it doesn't mean that your old car without ABS is dangerous).

The "somewhat dated consumer fuse unit" could mean an old 1960s panel with rewireable fuse carriers, or it could mean a 1980s unit with circuit breakers which is essentially no different from what is being installed today.   I've seen some things classed as "dated" when they're really not very old at all.   

I don't suppose you have any photos, do you? 

All in all, it's very difficult to be precise without seeing what's there and testing, and I'm afraid that this cursory electrical survey with the very confusing and muddled report is of little value. 

This part isn't very clear at all. 

You should have an earth bonding cable which runs from the distribution panel (fuse box) to the water supply pipe where it enters the house.  The connection is typically made with a clamp just above the main stopcock where the pipe comes through the Pfloor from underground.  You may then have what is called supplementary equipotential bonding between various other pipes, creating a metallic path between hot & cold feed pipes to a sink, between the various pipes connecting to the boiler, and so on.  These supplementary bonds are not normally extended back to the distribution panel, nor is there any such requirement in the wiring regulations.

So is he trying to say that the main earth bonding to the water system is missing?  Or is he looking at the supplementary bonding conductors and mistakenly thinking that they should have been extended back to the panel as well?    I'm not sure. 

Paul: This isn't my area at all (5V DC and under is more my thing) but I have a half memory of reading somewhere that earthing to water pipes was discouraged nowadays due to the prevalence of plastic pipes replacing the old metal water mains.  Does this ring a bell with you?

Thanks for the replies.  I think we may just get a local guy to go check a few things out if we decide to buy this house in the end.

I have a half memory of reading somewhere that earthing to water pipes was discouraged nowadays due to the prevalence of plastic pipes replacing the old metal water mains. 

Yes, in fact as long ago as 1966 the 14th edition of the IEE Regs. stipulated that water pipes shall not be used as the sole means of earthing for precisely that reason.  However, we still bond the internal pipework to the electrical system's main earthing terminal to ensure that the pipework itself is earthed to guard against faults. 

So we're not actually using the pipe to provide an earth for the electrical system, but instead making sure that the pipe is earthed by connecting it to the electrical system which is already earthed by some other means (separate rod, supplier's earth terminal, or bond to incoming neutral).

You have to watch for those plastic pipe couplings which have become very common these days as well, and apply clamps and bonding jumpers to maintain earth continuity around the joints.

Thanks for the replies.  I think we may just get a local guy to go check a few things out if we decide to buy this house in the end.

That's what I would suggest.  I wouldn't rely on the electrical section of your general survey at all.  If you have any concerns about the existing state of the electrical system, get a local electrician to issue you with a PIR - Periodic Inspection Report.   This should detail any specific problems found, although even with these there can be debate as to the severity of certain things, such as when something changes from a code 2 ("Recommend improvement") to a code 1 ("Dangerous, requires immediate attention").  But that aside, a proper electrical report will be of much greater value than that muddled "non report" of your general survey. 

Aren't we on 17th Edition regs now?  Or is British Gas lying to me? 

Personally - I'd always go for quote from BG - it's free.  The obvious advantage is they aren't likely to close shop and change their phone number once the work has been done.

And if your local contractor quotes you a great deal more...well.  I'd think twice.

YMMV. 

Aren't we on 17th Edition regs now? 

Yes, as I noted above the 17th Ed. took over fully from the 16th on July 1st.   The main changes which relate to the issues raised above are:

1.  RCDs are now specified for all regular 13A BS1363 outlets except those installed for specific appliances, whereas under the 16th they were only specified for sockets "likely" to be used for supplying equipment outdoors.

2.  Supplementary equipotential bonding is now not specified for bathrooms where all circuits therein are protected by a 30mA RCD.

There are quite a few others changes, many revolving around increased use of the RCD.  In fact it's already been noted on tech forums that the general attitude of the 17th Ed. now seems to be "If you can't fix it, RCD it."   

I can understand some of the changes.  But man...it's difficult explaining to people why their fuseboard is no longer up to Standards.  The more you explain, the more technical it gets. 

I tend to rely on the car metaphor (first there were seat belts, and ye the airbags did follow...until LO! side impact protection came into the regs).

I can understand some of the changes.  But man...it's difficult explaining to people why their fuseboard is no longer up to Standards.  The more you explain, the more technical it gets.

Yep, and frankly some of the changes are just getting silly.  Under the 17th Ed. in domestic premises it's now a requirement for any circuit which has cables running less than 50mm (2 in.) below the surface to be on an RCD, even where they are mechanically protected.   That means that in the typical British house where at least some if not all the drops to sockets and switches are on blockwork, every circuit is going to need RCD protection, even the cooker, immersion heater, and lighting circuits if so affected.   All circuits feeding outlets in a bathroom are now required to be on an RCD too, even a fully enclosed light fitting.   

Still, the good news for many UK-Y members is that BS7671 now allows regular sockets in a bathroom, although only if they can be mounted 3m from the tub or shower, so don't get excited yet unless you have a bathroom well over 10 ft. wide.