Boiler Cabling

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Hopefully a simple subject.

I'm redoing the kitchen, and part of the job has turned out to be a need to move the sockets etc. so that they don't end up behind the new tall units etc.. Besides they were always a little low on the wall having cut into the 'splash backs' (?) above the worktops.

While chasing out the existing cables I discovered that the heater in the adjacent room was supplied, not by cable, but by flex running horizontally through the wall to a single socket in the kitchen, from where it joined to another piece of flex that ran vertically up into the ceiling.

I'm unhappy with that and wish to replace it with cable.

What I wish to know is, is it permissible to spur off from a socket in the kitchen, or do I have to run a separate cable back to the c/u ? All it needs to do is to fire up the gas so the load should be minimal.

Also, if anyone has any 'tricks of the trade' that may help me sort out the cabling above the ceiling, without having to pull the ceiling down, that'd be a real benefit. It's rather depressing to think it may need to come down, as this job has grown considerably since the start, already.

Cheers.
 
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Is this a boiler (i.e. central heating) or a heater i.e. oil filled radiator, fan heater etc?
 
Gosh that was quick.

I'd need to be back home if you want details but it is a gas boiler that runs the central heating and also heats the water in the hot tank upstairs.
 
Gary0 said:
While chasing out the existing cables I discovered that the heater in the adjacent room was supplied, not by cable, but by flex running horizontally through the wall to a single socket in the kitchen, from where it joined to another piece of flex that ran vertically up into the ceiling.

Do you mean this bit as the C/H boiler or a heater?
 
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Sorry if I used an inappropriate term. It runs the central heating.

I called it a heater as it heats the water, but it's the main boiler for the central heating.

Has, as I recall, a couple of pipes coming out of the top which must be the feed and return, which supplies the heat to both the hot water tank in the floor above, and to all the radiators also.

It's nothing to do with single room heaters etc.

Thanks
 
Gary0 said:
Gosh that was quick.

I'd need to be back home if you want details but it is a gas boiler that runs the central heating and also heats the water in the hot tank upstairs.
OK so the current requirements aren't excessive (check the service plate to make sure). As long as it needs less than 13A you can run a spur in 2.5mm² T&E subject to the usual rules of spurs to a Fused Connection Unit (FCU) in the other room, then flex (heat resitant would be good) to the boiler itself. Put a fuse of the appropriate value in the FCU and you're done. Oh, actually it should be a Switched FCU so you can switch off the boiler without taking down the rest of the ring it's fed from. This is the sort of thing:
MKK1040.JPG

Make sure you get the type that has a flex-exit point.

And as you're working in the kitchen, you're obviously aware of part P :)

Cheers,

Howard
 
Obviously, and if there's anything I've missed I'll await the Amazon book recommendation ;)

Thanks for that. I'll check tonight, but I believe there is already a connection unit in the 'utility room'. It is the flex from it, to wherever it is picking up the mains (it seems probable it's some jb in the kitchen ceiling) that I wanted to put right.

If I can just connect cable from the existing connection unit to the ring at the nearest kitchen socket, then that'll be great.

Thanks all.

++++++++++++++++++++++++++++

http://www.odpm.gov.uk/stellent/groups/odpm_buildreg/documents/divisionhomepage/br0054.hcsp

Homework :)

________________________
moderator

please note 10a which is here
 
DIY Electrical work and the law

On January 1st 2005 legislation came into effect which brought electrical work in dwellings under the Building Regulations, and made it a controlled service. This amendment to the Building Regulations, known as "Part P", imposes safety requirements, and also classifies electrical installation work into two basic categories, notifiable and non-notifiable.

Essentially the distinction is between major work, or work in what are deemed high-risk areas such as kitchens, bathrooms and gardens, and minor work such as replacing switches or adding sockets to existing circuits. (NB to those with a knowledge of the IEE Wiring Regulations, the term "minor work" is used here in its generic sense rather than the meaning defined in the Wiring Regs.)

A very important and fundamental point to note is that DIY electrical work has not been outlawed. It has been brought within the remit of the Building Regulations and cannot be carried out as freely as it was before, and in many cases cannot be carried out without involving your local council, but you may still DIY.

Major work is classed as notifiable, i.e. it must be notified to your Local Authority's Building Control department (LABC). How this happens depends on who does it.

If the work is carried out by an electrician who is registered with one of the organisations who administer self-certification schemes, (sometimes referred to as "Competent Person" schemes) they carry out the work and report the details to their scheme organiser, who then notify the appropriate LABC that the work has taken place, and that it has been certified by the person who carried it out as being in compliance with the Building Regulations. You may be familiar with this method of operation if you have ever had windows replaced by a FENSA member.

If the work is carried out by someone who is not registered with one of the schemes, be they an electrician or another type of tradesman (e.g. kitchen fitter) who has chosen not to register, or a DIYer, then it must be notified to LABC in advance in the same way that any building work which requires their involvement is notified in advance. And just like when you are building an extension, or converting a loft, etc, there is a fee payable to LABC to cover their activities related to checking compliance with the Building Regulations. (But see "LABC Issues" below regarding this).

Another important point to note is that apart from a Building Inspector, nobody can certify someone else's work as being compliant with the Building Regulations. Unless arranged by or in cooperation with LABC, a 3rd party electrical inspection is of no value in terms of complying with the law.

The full text of the legislation can be found here: http://www.opsi.gov.uk/si/si2004/20043210.htm and it is worth making the effort to read it, and understand it, because there is a lot of misinformation on the Internet, some of it put out by organisations with a vested interest in pretending that DIY work is illegal, some of it by LABCs who have either misunderstood the legislation, or who are also attempting to mislead the public in order to reduce the amount of work notified to them by non-self-certifying people, some of it, surprisingly, by the ODPM themselves (The Office of the Deputy Prime Minister were responsible for the legislation), and much of it on electrical advice and discussion fora like this one.

At the time of writing (September 2005), the following work was classed as not needing notification to LABC:

[code:1]1. Work consisting of -

(a) replacing any socket-outlet, control switch or ceiling
rose;

(b) replacing a damaged cable for a single circuit only;

(c) re-fixing or replacing enclosures of existing
installation components, where the circuit
protective measures are unaffected;

(d) providing mechanical protection to an existing
fixed installation, where the circuit protective
measures and current carrying capacity of
conductors are unaffected by the increased thermal
insulation.


2. Work which -

(a) is not in a kitchen, or a special location,

(b) does not involve work on a special installation, and

(c) consists of -


(i) adding light fittings and switches to an
existing circuit;

(ii) adding socket outlets and fused spurs to an
existing ring or radial circuit; or

(iii) installing or upgrading main or supplementary
equipotential bonding.


3. Work on -

(a) telephone wiring or extra-low voltage wiring for the
purposes of communications, information technology,
signalling, control and similar purposes, where the
wiring is not in a special location;

(b) equipment associated with the wiring referred to in
sub-paragraph (a).
[/code:1]
The terms "kitchen", "special installation" and "special location" are defined in the legislation.

Like any law, things can change, and you are urged to ensure that you make yourself familiar with the law as it stands now, not necessarily as it was when this document was written.

The starting point on the ODPM website for information related to Building Regulations is http://www.odpm.gov.uk/stellent/gro...ments/sectionhomepage/odpm_buildreg_page.hcsp and a list of the relevant legislation can be found at http://www.odpm.gov.uk/stellent/groups/odpm_buildreg/documents/page/odpm_breg_600270.hcsp .

It is in the nature of the Internet for sites to change, and it may well be that today, when you are reading this, the links above no longer work, and you will have to search for the pages you want.


Useful Information

On the ODPM website there are a number of "Approved Documents"
( http://www.odpm.gov.uk/stellent/groups/odpm_buildreg/documents/divisionhomepage/br0041.hcsp ). These are not definitions of the law, nor do they tell you what you must, or must not, do. Instead they give guidance on ways in which the law can be satisfied. They do point out that you are not obliged to adopt any solution contained in them if you prefer to meet the requirements in another way, but that said they are useful as they contain common sense advice and often there is no good reason not to adopt the solutions they contain.

Approved Document P can be found here: http://www.odpm.gov.uk/stellent/groups/odpm_buildreg/documents/page/odpm_breg_br1007.pdf .


Technical Requirements

The technical requirements laid down by Part P are remarkably simple. They are:

  1. Reasonable provision shall be made in the design, installation, inspection and testing of electrical installations in order to protect persons from fire or injury.
  2. Sufficient information shall be provided so that persons wishing to operate, maintain or alter an electrical installation can do so with reasonable safety.
It is worth noting however that they apply to all work, not just notifiable work, no matter who does it. So a DIYer adding a socket or a fused spur to a ring final circuit must work to the same technical standards as a registered electrician doing a complete rewire.

The biggest practical issue that arises is testing. To carry out testing of electrical circuits requires expertise and equipment, neither of which are likely to possessed by the average DIYer. So although Part P allows a DIYer to replace an entire circuit cable if it is damaged, without notification, it is arguable that he could not be sure that he had done it properly unless he carried out a series of tests on it, something he would probably be unable to do.


The IEE Wiring Regulations, aka BS 7671

Surprisingly, perhaps, Part P does not alter the status of the Wiring Regulations. They are still non-statutory, and there is still no legal requirement to adhere to them in domestic installations. This is a source of great discomfort to many electricians, and some of them will jump through hoops to try and prove that they are mandatory, but the fact remains that they are not.

HOWEVER, adherence to them is a very good way of ensuring that you meet the technical requirements of Part P, and you would need a very good reason, and a very good understanding of what you were doing, to decide to not adhere to them.


LABC Issues

As mentioned above, some LABCs are spreading misinformation, either by accident or design, about the status and acceptability of electrical work done by DIYers or other non-registered people.

These include:

1) Stating that such persons simply cannot carry out notifiable work, and that it must be done by registered electricians. The legislation referenced above, Statutory Instrument 2004 No. 3210 The Building (Amendment) (No.3) Regulations 2004 makes it quite clear that this is not the case. LABCs are not allowed to refuse to process Building Notices submitted by non-registered people.

2) Stating that work carried out by a non-registered person must be inspected and tested by someone who is registered. Again, there is no mention of this requirement in the statutory instrument.

Recently the ODPM issued a circular to local authorities making it absolutely clear that they are not allowed to do this:

http://www.odpm.gov.uk/stellent/groups/odpm_buildreg/documents/page/odpm_breg_037024.hcsp

3) Attempting to impose extra charges to cover the inspection and testing of work done by a non-registered person. An LABC may well elect to subcontract inspection and testing if they do not have the capacity to do it themselves, but they are not allowed to charge extra because of this – the cost to them of subcontracting must be borne by them

Individual local authorities co-ordinate their services regionally and nationally (and provide a range of national approval schemes) via LABC Services. (http://www.labc-services.co.uk).

I recently posed LABC services the following question:

"My local Building Control dept has told me that because of staffing problems they are unable to inspect some building work, and will have to sub-contract it, and that I will therefore have to pay this cost on top of their fees.

Are they allowed to do this?
"

Their reply was:

"Building Regulation fees are set to a scale that embraces the whole scope of what may be necessary in respect of checking and approving the plans and inspecting the work. The input necessary can vary according to the circumstances of a specific scheme, but the fees are not variable due to this feature.

The local authority has a legal duty to carry out the Building Regulation function to a proper degree. This can also vary in extent according to the demands of any scheme and considerable discretion rests with the authority. However they are responsible to give a proper service within the fee and cannot charge extra for the reason you mention. Indeed if they failed to inspect yet still charged you might have a case for a refund
."
 
Interesting.

At the risk of attracting a lot of flak, I think all this is an unwarranted intrusion into what individuals can do in their own home. Appreciate some of the stuff I've discovered in the past really ought to have been prevented, but it was still my moral responsibility to get it all checked out myself, before I bought the place. Seems the government want control over everything. I did write to Liberty about it, they didn't even bother to reply. Creeping restrictions not serious enough for them I guess. Will get it checked out once done.

Meanwhile, the sticker on the bottom of the boiler says 0,032 + 0,02 A which I take means 52 mA. Unsure why it's shown as 2 values though. But it's a fairly insignificant load in any case.

Actually
"Competent Person" schemes
sounds very interesting. Wonder if that's done at night school, and how much it'd cost. "No" and "Too much" probably.
 
Excellent review of the situation BAN.

In fact it could do with airing in place of the ODPM add on TV
(Not yet seen it on TV here by the way)
 
This job has progressed and I'd like to reopen the issue if I may. Isn't going to be succinct, hope that doesn't put many off, sorry. :oops: :)

First. Is it permissible to bury flex, rather than cable, in the wall ? This is the original situation and I am of the view that it is not permissible, but I'd appreciate an answer from those in the know.

Why do I ask ? Because since my last post I have taken down the ceiling in order to remove cables that are now no longer required (they would not pull through) and it has allowed me to follow the route taken by the boiler flex.

It turns out the situation is as follows, and it is confusing me.


The boiler has electricity supplied by a flex coming from a FCU on the wall next to it. So far so good.

This then goes through the wall (still using flex) and runs horizontally, in the wall, to where a wall-box used to be before I removed it. The box used to house a single outlet socket, but the flex didn't join to that, it joined to a choc block connector that had been jammed in there too. Then a further piece of identical flex runs vertically in the wall, up to the ceiling.

I had assumed this made its way to a source of mains power elsewhere, as the red wire seems to be permanently live.

In fact it reaches the top and then runs along the rafter to the other side of the room where it enters what used to be the external wall (before the extension was built). It is then in the 'airing cupboard', along with the hot tank etc.. I checked where it goes from here, and it is to the pump.

A second identical flex enters the pump at the same place. (I've not opened the pump up as I don't wish to disturb something that is working, but I have assumed the two are connected to the same points. This may not be the case.)

The other flex then goes to a box of electrical connections. Clearly part of the heating system, but so full of wires it is difficult to trace where each goes. And even when I think I have traced one, the 'key' on the inside of the lid gives precious little information as to what connection point is what.


Does any of this sound a familiar situation to anyone ? I have no desire to mess with the electrical box, but my alternatives seem to have reduced somewhat.

I can leave the flex in the wall, perhaps re-routing it slightly better, quoting, "if it ain't broke, don't fix it" as justification. Or I can replace the flex with cable for part of the routing, but that'll mean at some point, cutting and joining the new cable to existing flex.

I'm unsure of the best next step. Any suggestions gratefully welcomed.
 
It is fairly regular for a CH system to have power going from source (usually the CU) TO the wiring center (in your airing cupboard- the confusing, scary bit). This is all interlinked with your control valves, programmer, etc, and it is from here that the supply to the boiler starts.

The flex between the wiring center and the boiler, is it regular 3 core? (L, N + E)?

If so, then you will probably be ok simply replacing the flex with T+E from the wiring center to the FCU at the boiler. So long as you router the T+E appropriately and according to the regs.

If what I describe is the case, and the wiring centre is supplied directly from the consumer unit, then there really ought to be a separate FCU (fused at 3A) at the wiring centre too. This should isolate everything- controls and boiler too. And if that FCU is in place with a 3 A fuse, then you can (probably) use 1.0mm T+E from there to the boiler.

I hope that makes sense.


----------------------------------------------

Just re-read some of your post, i can expand a little:-

A second identical flex enters the pump at the same place. (I've not opened the pump up as I don't wish to disturb something that is working, but I have assumed the two are connected to the same points. This may not be the case.)

The wiring centre output a switched live, neutral, earth where the live is neutral when there is boiler demand. In your system, this has been wired to the pump, and then from the pump on to the boiler. The pump and boiler are in parralel.

You should open the pump connections. Leave the flex from pump to wiring centre in place, remove flex that goes to the boiler from the pump.

Fit new cable from the FCU next to the boiler, all the way to the wiring centre. It should connect to the SAME terminals that the pump does.
 
Yes, it seems to be regular 3 core flex. My desire to change it wasn't due to not believing it was up to the task, it was a general distaste for flex in the wall, a belief it shouldn't be done. (Plus the route it was taking, and the choc block, etc..)

Yes, the control unit is on an adjacent wall and connects via separate flex to a) the wiring centre, b) a FSU labelled 'boiler mains' and c) a house thermostat dial (When I first moved in and had to get a plumber to get the system working he expressed surprise the control dial was upstairs, but it seems to work ok if always set to max.) That all seems to fit with your description.

So you are suggesting that the boiler supply need not go via the wiring centre and pump, but can go directly from there ? Or alternatively it can go via the wiring centre only ? Things are becoming clearer. Thanks for that.
 
Gary0 said:
Yes, it seems to be regular 3 core flex. My desire to change it wasn't due to not believing it was up to the task, it was a general distaste for flex in the wall, a belief it shouldn't be done. (Plus the route it was taking, and the choc block, etc..)

flex should not be used for fixed wiring. it's not allowed under the regs/

Yes, the control unit is on an adjacent wall and connects via separate flex to a) the wiring centre, b) a FSU labelled 'boiler mains' and c) a house thermostat dial (When I first moved in and had to get a plumber to get the system working he expressed surprise the control dial was upstairs, but it seems to work ok if always set to max.) That all seems to fit with your description.

yep, fairly normal

So you are suggesting that the boiler supply need not go via the wiring centre and pump, but can go directly from there ? Or alternatively it can go via the wiring centre only ?

The wiring centre is where your control logic happens. All the inputs from DHW cylinder stat, room stat, and programmer, are "mixed" there, and there is an output switched live to tell the boiler when to fire. Same signal tells pump when to run.

It's poor practise to do what your installer has done. You need to run *cable* from the wiring center to the boiler, and flex from the wiring center to the pump. The are wired to the same terminals inside the wiring center.

You must not wire your boiler up to the mains directly, from say a fused spur. If you did that, the boiler would run all the time.

Make a very very careful note of what wire goes where in the wiring center before you disconnect anything.
 
slippyr4 said:
Make a very very careful note of what wire goes where in the wiring center before you disconnect anything.
:D :D :D

Cheers again. Got all that. Not tonight methinks. Need to wait for a time when the pipes in front of the wiring centre ain't so hot ;)
 

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