Advice needed about earthed boiler

[Lucie 15]

Good morning all,

We need a little bit of advice; we are looking to buy a property, and during one of the visits, the owner told us that he earthed his boiler himself as it was not done. He claims to have studied electronics engineering and other related things, but my partner is a bit dubious on how qualified that makes him.
The boiler has since been serviced many times, and the seller has provided recent gas and electrical certificates, which were both passed.
At my last visit, he showed me the earthing on the main fuse box (downstairs front room), and said the wiring had been done to the boiler (all the way to bathroom upstairs, back of the house). There is also an on/off switch outside the bathroom door. The wiring at least seems to have been well done, as I didn't see/notice it.
Should we worry about this and get it checked now, or is it likely that we can wait and get it check after the sale?
And also, what kind of prices would we be looking out in London, Croydon area?

Many thanks for your advice.

 

[littlespark]

If the electrical certificate was an eicr, (electric installation condition report) and it covered the whole house, then nothing to worry about…
On the other hand, it may have been a certificate for only recent work, and be limited to maybe only one circuit.

have a look at the fuseboard, and see if it has any rcd’s. (A photo would be good, but obviously difficult if you’re not there yet)

A picture of the circuit chart off the certificate would be useful too, but you’de have to redact any personal info such as names, addresses, phone numbers etc of yourself or the contractor that did the cert.

I think the seller is just being overly keen to impress by saying he’s done the work, possibly to bring it up to regulations, but conversely, what he has done may not have been needed in the first place.

 

[Vortigern]

It is a bit vague "earthed the boiler" All boilers should be earthed by the fact the supply comes in with Live Neutral and Earth wire in the form of flat grey twin and earth cable. Why he felt therefore it needed earthing is a strange one. Perhaps he thought it need supplementary bonding. Ask him why exactly did he do it. Any piccys? Even so I imagine it wont do any harm. And as above really. Cost of a call out in London, £95 and upwards to just check it.

 

[Lucie 15]

Thank you for replying so fast!
@Vortigern, I am not at all familiar with electrical works and/or boilers, so I am just quoting the seller! He said it as if we should have found it ludicrous that his boiler was not earthed...When he showed me the fuse box, he pointed at a green and yellow cable and said it was going all the way up to the boiler upstairs.

 

[Lucie 15]

Thank you for replying so fast!
@Vortigern, I am not at all familiar with electrical works and/or boilers, so I am just quoting the seller! He said it as if we should have found it ludicrous that his boiler was not earthed...When he showed me the fuse box, he pointed at a green and yellow cable and said it was going all the way up to the boiler upstairs.

I have found the certficate and will attach it. There is also a picture of the fuse board, if that helps!

 

[brianmoooore]

Not a single C3????? How can he think that installation fully conforms with the 18th?

 

[loz2754]

Hi and welcome.
I took a look at the report and it's generally a good report, but a few anomalies, mainly in the schedule of items inspected.
However, the earth bonding cables are in place according to the report, which is good.

One thing that would concern me is the main switch being a 100mA RCD. For 2 reasons. Reason 1 - it's not good practice to have one RCD protecting all of the outgoing circuits, because a fault to earth in one circuit will result in all of the circuits automatically switching off. Not ideal.
Reason 2 - more importantly, none of the circuits have 30mA RCDs. 30mA RCDs are very important, and the lack thereof should have been more clearly detailed in the observations section of the report. Moreover, without RCDs for certain aspects of the installation, there should be one or more C2 codes, which means the outcome of the report should read "unsatisfactory".

 

[westward10]

Aside from multiple errors on the Schedule of Inspection that main switch is BS4293 and not EN61008. I probably wouldn't put too much faith in the person that undertook that EICR.

 

[telectrix]

Hi and welcome.
I took a look at the report and it's generally a good report, but a few anomalies, mainly in the schedule of items inspected.
However, the earth bonding cables are in place according to the report, which is good.

One thing that would concern me is the main switch being a 100mA RCD. For 2 reasons. Reason 1 - it's not good practice to have one RCD protecting all of the outgoing circuits, because a fault to earth in one circuit will result in all of the circuits automatically switching off. Not ideal.
Reason 2 - more importantly, none of the circuits have 30mA RCDs. 30mA RCDs are very important, and the lack thereof should have been more clearly detailed in the observations section of the report. Moreover, without RCDs for certain aspects of the installation, there should be one or more C2 codes, which means the outcome of the report should read "unsatisfactory".

agree. several C2s and C3s for lack of 30mA RCD protection.

 

[Lucie 15]

Not a single C3????? How can he think that installation fully conforms with the 18th?

I am sorry, but I have no idea, what you mean!!!

 

[Lucie 15]

Hi and welcome.
I took a look at the report and it's generally a good report, but a few anomalies, mainly in the schedule of items inspected.
However, the earth bonding cables are in place according to the report, which is good.

One thing that would concern me is the main switch being a 100mA RCD. For 2 reasons. Reason 1 - it's not good practice to have one RCD protecting all of the outgoing circuits, because a fault to earth in one circuit will result in all of the circuits automatically switching off. Not ideal.
Reason 2 - more importantly, none of the circuits have 30mA RCDs. 30mA RCDs are very important, and the lack thereof should have been more clearly detailed in the observations section of the report. Moreover, without RCDs for certain aspects of the installation, there should be one or more C2 codes, which means the outcome of the report should read "unsatisfactory".

Hi, and thank you for your advice.

In the recommendations, they do suggest a dual 30mA RCD. would that help?

 

[Lucie 15]

Well, thank you all for your quick replies, especially on such a brilliant Sunday!
Not sure what we'll do then, if we should pursue it before or after purchase...Now, I understand that I should have paid more attention during technology and physics lessons at school! ??

 

[littlespark]

A C3 basically means “improvement recommended” which isn’t dangerous in any way but could do with being upgraded.
C2 means potentially dangerous…. A secondary fault could cause serious injury
C1 is immediately dangerous…. Think bare live wires hanging out the wall.

The fact that it has an rcd is better than none at all, but it’s not as sensitive as what is required nowadays, and as mentioned, it’s up front, which means a fault on any circuit leaves you with no power at all.

the board is quite old… and in your neck of the woods, I’d estimate £1k to have it changed…. (Possibly much more)
Having it changed may bring up other faults that are not yet apparent, so add x amount on top for repairs. Hopefully it doesn’t need fully rewired. 10 to 20k off the selling price should cover it…

 

[brianmoooore]

I am sorry, but I have no idea, what you mean!!!

There is no requirement for an old installation to conform with the current regulations (with a few exceptions), as long as it was installed to the regulations in force at the time it was installed.
However, it is tested to the current regulations, so anything that conformed originally, but now doesn't, should be marked C3 as a minimum on the test results, and not just ticked.

 

[timhoward]

I'm not sure why no-one can see this C3:

 

[ipf]

Aside from multiple errors on the Schedule of Inspection that main switch is BS4293 and not EN61008. I probably wouldn't put too much faith in the person that undertook that EICR.

Strikes me as unbelievable that all IR readings are perfect....in such an installation.

 

[loz2754]

I'm not sure why no-one can see this C3:
View attachment 87824

I saw it immediately but dismissed it because it's meaningless without clarification.

 

[timhoward]

I saw it immediately but dismissed it because it's meaningless without clarification.

I've since read the whole thing including schedule of inspections...and see exactly what you and others mean.

Keeping things simple as the original poster is wanting advice - the report says the actual wiring is 17 years old, and perfect in every single way. One of the tests (Insulation Resistance) says it's as good as the day it went in which would be rare. It's hard to therefore assess what testing was actually carried out as I'm not alone in suspecting some tests were skipped.

I'd be inclined to get a couple of quotes for a new consumer unit and ask for that amount off the purchase price. If there's an 100ma RCD as the main switch and it isn't tripping every minute then I'd expect the wiring to be healthy and serviceable. I'd therefore be a bit surprised if it needed a rewire.

You could say that you have had some electricians review the report and there is a consensus that it contradicts itself, and in particular if it only has 100ma RCD protection then some of the items shouldn't be ticked that are ticked. Therefore you'd like a quote for a new CU with 30ma RCD protection for all circuits.
I hope that is of some help.

 

[westward10]

Based on the BS4293 device, withdrawn 2009 and the BS3871 devices, withdrawn 1994 I would say 17 years is incorrect.

 

[UNG]

Reading that EICR I can't help but think it is a work of fiction,
The test results show an R1 + R2 reading of 0.44Ω on the main switch / RCD whats that about, even if it was the Ze on another page that is given as 0.26Ω
Cooker supply is 10mm² with a 6mm² cpc when 10mm² T&E has a 4mm² cpc
5.11 Provision of additional protection by 30mA RCD is all ticked with no 30mA RCD installed

A good start would probably be another EICR done properly

 

[pc1966]

Getting another EICR done might be the best way to sleep easily knowing everything is just fine. It is not that unusual to see errors being made, but equally it casts some doubts about how useful the results are. The various folk above have gone in to that in some detail.

Having near-perfect IR (insulation resistance) on an older property is quite possible, my own flat was rewired in the early 80s so around 40 years old and all but one circuit was above 1000M ohm, but one of the light circuits varies from around 200M to 800M depending on how damp it has been. But that is not always the case by any stretch so it is one of the slightly suspicious pointers as to whether it was really measured or not.

The C1/C2/C3/FI codes are all about how serious a problem is found, though FI = further investigation when it could not be determined at the time of the inspection (problem suspected but too invasive to check such as lifting floorboards, or needed access to locked areas, etc).

The Best Practice Guide #4 has a lot of information and examples of typical issues and suggested coding:

https://www.----------------------------/professional-resources/best-practice-guides/

Basically it is not about whether an installation is 100% up to date, but about how much risk there is from aspects that are not as installed today. So something like old colour coded wire is not compliant but has zero impact on safety (assuming insulation OK, etc).

The guidance from BPG#4 differs slightly from some other guidance (e.g. NICEIC) but most agree it is the most appropriate starting point, however, the electrician doing the inspection is expected to apply their own judgment as some things that are not complaint will have different risks depending on the particular setup.

 

[pc1966]

Folk have commented on the 100mA up-front RCD used as a main switch. That was quite common practice for a TT supply (local earth rod in the ground, no earth from the supply) but your is down as TN-S (supply has earth, separate from neutral) and it looks quite old, so I wonder if your current board might have simply replaced the configuration of a much older setup from when there was no supplier earth.

The risk here is a 100mA RCD will provide virtually no protection against electric shock, and that is why both the original report and the folks here are suggesting you get a new board fitted that has 30mA RCDs.

While it is slightly more expensive most would suggest a board using all RCBOs - these combine the over-current protection of a MCB with the shock protection of an RCD and they have the advantage over a dual RCD board that a fault on one circuit does not take out the supply to several circuits due to a shared RCD.

In reality you should not see them trip too often, but 30mA RCD are more prone to nuisance trips than other types (fuse, MCB, 100mA delay type RCDs, etc)