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16th edition fuse box question

I've just found out that when we had our electric fuse box replaced about a month ago a 16th edition one was fitted. The electrician says it's because the newer one wouldn't fit. His response today was:

"its the only mantel unit that we could get to fit into the gap,as I said to your husband, as cables to the upstairs flats are wired through your unit,it has reduced the room for fitting anything else in there. As you know even fitting that one was a struggle."

It's true it's a very tight squeeze getting it into the box, but will this cause a problem in the future? We only had the fuse box upgraded because we wanted an electrical safety certificate as we are renting our place out. I don't want to be told in 5 years time when we have a new safety inspection done that we'll have to have it upgraded yet again.

Please could you let me know your thoughts?

Thank you,



Thank you for all your replies. I have asked for further info form the electrician who installed it and this is what he said:

"This will not cause any complications at all, there is no option unless you completely remove the steel mantel unit and ask to have the rising cables to the other flats removed and rerouted which would be a logistical nightmare. I am happy to send you a statement of fact regarding your installation. You will not fail a further inspection."

I was sent a copy of the electrical safety certificate after the work was done but I haven't read it I'm afraid. I'll have a look and see what it says.

4 Answers from MyBuilder Electricians

Best Answer

Since 1st of July 2008, the 17th edition wiring regulations (BS7671:2008) has required that RCDs protect virtually all doemestic circuits. Therefore new consumer units that are retrofitted to existing wiring must be of the dual RCD high integrity type or that all circuits are protected by individual RCBO's.

I would agree that mantel units designed in the 1940's are not easy to upgrade and your electrician should have thefore advised you of the need to fit a surface mounted consumer unit outside of the mantel unit and extended the circuits to the new position. Were you given this option at all?

Fitting a 16th edition consumer unit is an improvement over old reqwireable fuses, but does not meet the current regulations. As you have correctly highlighted, at any future inspection this will always be noted as a defect against the current 17th edition standards as it is non-compliant to with BS7671:2008. Lack of space is not a justification for lack of compliance!

For completeness, were you issued a full 17th Edition electrical test certificate staing that the work carried out meets BS7671:2008 or is the certificate ammended with a comment stating that not all circuits are RCD protected? I would have also thought that the electrician would have had problems registering this work with building control as it does not fully meet BS7671:2008. I take it that you have you recieved the building control compliance letter through the post yet? If so what work has been registered with LABC?

Its worth just asking your installer if RCBO's can be fitted instead if space is a real issue.

If you have not got a copy already go to the Electricity Safety Council website and download the FREE Landlords electrical guide. It has loads of good info and clearly sets out your responsibility as a landlord.

If it were my property I was renting, then i would want full RCD protection on every circuit as required by the regulations, just in case the tenant tried to sue me if they got a shock etc.

Hope this helps, please click "like" if it does!


Answered 1st Dec 2011

Hi there
A 16 th edition does not comply with the current 17 th edition
If the electrician says it woulnt fit then the existing fuse box could be upgraded to 17 th edition this can be done by replacing the mcbs with individual rcds


Answered 1st Dec 2011

Briony ,The electricians responce of it wouldnt fit is not acceptable . 17th edition should include rcd protection to all circuits in normal cicumstances by means of rcd's or rcbo's within the consumer unit , there are exceptions such as circuits with surface run cables , cables buried over 50mm from wall surface or for specific circuits supplying fixed appliances which should be labelled as such . If he couldnt get a 17th edition consumer unit to fit he should have used a 16th edition and included rcbo's to cover all circuits not covered by the rcd ( unless of course he has installed all circuits covered by the single rcd in the unit , again this is not good practice as you would lose all circuits in the case of a fault , seperation is necessary for safety and convenience. Hope this helps wayne soppitt ( WPS Electrical Services ) .


Answered 1st Dec 2011

A 16th edition split load board is the same size as a 17th edition dual RCD board.

He may have fitted a board with an RCD main switch which is ok but not very practical


Answered 1st Dec 2011

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