Fuse Box
Installation (Consumer Unit)
Still running an old wire-fuse board? Our approved electricians carry out complete fuse box installation across London: 18th Edition metal consumer units with full RCD protection, tested, certified and notified under Part P.
- 18th Edition Metal Units
- RCD / RCBO Protection
- EIC Issued On Completion
- Part P Notified For You
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Simple, All Inclusive Pricing
Supply, fit, full testing and certification. All prices include VAT.
| Board Size | Price (Inc VAT) | Action |
|---|---|---|
| 6 Way Consumer Unit | £580* | |
| 6-10 Way Consumer Unit | £680* | |
| 10-15 Way Consumer Unit | £860* | |
| 15-20 Way Consumer Unit | £1080* | |
| Double Decker Consumer Unit | £1150* | |
| Skeleton Board | £980* |
Your Fuse Box Installation Guide
Everything a London property owner needs to know about fuse box installation, in the order people usually ask it. Jump straight to the part you need.
- What is a fuse box installation?
- Why your property needs one
- Part P Building Regulations
- BS 7671 and the 18th Edition
- Why old boards fail an EICR
- Who needs an upgrade?
- RCD, RCBO and surge protection
- What it costs in London
- Preparing for the visit
- What happens on the day
- Certificates and testing
- How it fits your other checks
What Is a Fuse Box Installation?
A fuse box installation is the removal of the existing fuse board and the fitting of a modern consumer unit built to the 18th Edition of BS 7671, the British Standard that governs every fixed electrical installation in the UK.
The board is the control centre of the property. Every circuit — lights, sockets, cooker, shower, immersion, outbuilding — passes through it, and every protective device that is supposed to disconnect a faulty circuit lives inside it. When that equipment is forty years old and made of rewirable fuse carriers, it cannot do the job the current standard expects of it.
A replacement board is metal-clad rather than plastic, carries either a pair of residual current devices or an individual RCBO on every circuit, and normally includes a surge protection device and a main switch that isolates the whole installation. The work is notifiable under Part P of the Building Regulations, so the finished job comes with an Electrical Installation Certificate and a Building Control notification lodged on your behalf.
Metal Enclosure
Non-combustible steel housing, as the 18th Edition requires for domestic boards.
RCD / RCBO
Life-saving earth fault protection on every circuit that needs it.
Full Circuit Test
Insulation resistance, continuity and polarity proved before anything is energised.
EIC & Part P
Electrical Installation Certificate plus Building Control notification.
Key Information
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01
Duration
Typically 4-6 hours with the power off.
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02
Standard
BS 7671:2018, the 18th Edition Wiring Regulations.
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03
Paperwork
EIC issued plus Part P notification lodged.
The power goes off
The whole property is isolated for most of the working day while the board is changed and every circuit is tested, so plan around freezers, home working and any powered medical equipment.
Why Your Property Needs a Fuse Box Installation
The single biggest reason to replace an old board is shock protection. A rewirable fuse or an early miniature circuit breaker protects the cable from overload; it does nothing at all to protect a person who touches a live conductor. A residual current device compares the current flowing out with the current coming back and disconnects in around 30 milliseconds if the difference reaches 30 milliamps, which is the margin that keeps an electric shock survivable.
The second reason is fire. Loose or corroded terminals inside a board heat up under load, and a plastic enclosure will burn and drop molten material onto whatever is underneath it — usually a hallway cupboard or the space under the stairs. Since 2016 the standard has required domestic boards to be housed in non-combustible material, which in practice means steel, so that any fault that does start inside the enclosure stays inside it.
The third reason is entirely practical. An old board is the single most common reason a rental property comes back with an unsatisfactory report, and a landlord who has to arrange remedial work in a hurry pays more and loses more time than one who plans the upgrade. If your report has already flagged the board, the sensible move is to book the work rather than patch around it.
The Rules Behind Every Consumer Unit Upgrade
Fuse box installation and Part P Building Regulations
Replacing a consumer unit in a dwelling is notifiable work under Part P of the Building Regulations. That means the job has to be either carried out by an electrician registered with a competent person scheme, who self-certifies the work and notifies Building Control, or notified to the local authority in advance and inspected by them. The Approved Document P guidance published by the government sets out exactly which jobs are caught.
Our electricians are registered with NICEIC and NAPIT, so the notification is handled for you and a Building Regulations compliance certificate follows in the post. Keep it with the deeds. A missing notification is the sort of thing that surfaces during conveyancing, when a buyer’s solicitor asks for evidence that the board was changed lawfully and an indemnity policy becomes the only alternative.
It is worth being clear about what Part P is not. It is a Building Regulations requirement about who may do the work and how it is recorded; it is not a safety standard in itself. The technical rules the installation must satisfy come from BS 7671.
BS 7671 and the 18th Edition
BS 7671:2018, the IET Wiring Regulations, is the standard every new board is designed and tested against. The requirements that matter most on a domestic replacement are the non-combustible enclosure, residual current protection for socket circuits and for cables buried in walls at a shallow depth, and consideration of a surge protection device against transient overvoltages.
Standards move, and a board installed to an earlier edition is not automatically dangerous. What matters is that the installation as it stands is safe for continued use — which is precisely the judgement an inspector makes when they produce an EICR certificate for your property. Where a landlord is involved, the Electrical Safety Standards in the Private Rented Sector (England) Regulations 2020 require an inspection at least every five years and remedial work within 28 days of a report that identifies it.
For plain-English background on protective devices and what they actually do, the charity Electrical Safety First is a reliable independent source. Rules and guidance change over time, so check the current published version before relying on any detail here.
The Installation Process
Isolate, test, connect, certify — nothing is energised until it has been proved safe.
Isolation
Engineer shows ID, agrees the circuit schedule and isolates the supply at the main switch.
Strip Out
Old board and any wooden backboard removed; a fire-resistant mounting surface fitted where needed.
Dead Testing
Continuity, insulation resistance and polarity proved on every circuit before it is connected.
Certification
Live tests, RCD trip times, labelled schedule and your Electrical Installation Certificate.
Why Old Wire-Fuse Boards Fail an EICR
Inspectors do not fail a board because it is old. They fail it because of what the old design cannot do, and the same handful of observations come up again and again on London properties.
Rewirable fuse carriers, wooden backboards, plastic enclosures under a staircase, no residual current protection on socket circuits, and cables that have been added over the years with no room left in the board — each of those is a recognised observation, and several of them are enough to make a report unsatisfactory on their own.
Where that happens, replacing the board is usually cheaper and faster than trying to modify what is already there. Spare parts for a board made in the 1970s are scarce, the enclosure will still be the wrong material afterwards, and you will be paying twice within a few years.
No RCD Protection
Socket circuits and buried cables without residual current protection are a routine C2 observation.
Combustible Housing
Plastic enclosures and wooden backboards give a fault somewhere to spread instead of somewhere to stop.
Common Observations
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01
Rewirable fuses
No shock protection and no reliable disconnection time.
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02
No spare ways
Nowhere to add a shower, cooker or EV charge point circuit.
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03
Missing labelling
Nobody can identify which switch isolates which circuit in an emergency.
C1 and C2 codes
A report that records a C1 or C2 observation is unsatisfactory, and a landlord in England must have the remedial work completed within 28 days of receiving it.
What Is Included With Every Consumer Unit We Fit
One fixed price covering the hardware, the labour, the testing and the paperwork.
The Hardware
A new metal-clad consumer unit with main switch, MCBs or RCBOs to suit your circuits, and surge protection where the installation calls for it.
The Testing
Every circuit tested dead before connection and live afterwards: continuity, insulation resistance, polarity, loop impedance and RCD trip times.
The Paperwork
Electrical Installation Certificate with full schedule of test results, a labelled circuit chart inside the cover and Building Control notification under Part P.
Who Needs a Fuse Box Installation?
Landlords, homeowners and commercial premises
Landlords make up most of the work we do. A private rented property in England needs a satisfactory inspection report at least every five years, and where the report flags the board, an upgrade is the route back to compliance. Agents will not market a property with an outstanding C1 or C2 observation against it, and a licensing officer visiting an HMO will ask to see the paperwork.
Homeowners come to us for a different set of reasons: a board that trips whenever the shower and the kettle run together, an extension or a new kitchen that needs circuits the existing board has no way to accommodate, an electric vehicle charge point, or a survey during a purchase that recommended replacement. There is no legal deadline for an owner-occupier, but the safety argument is identical.
Commercial premises are a separate discipline. Distribution boards in shops, offices and small industrial units are often three-phase, the inspection cycle is shorter, and the paperwork differs. If that is your situation, start with our commercial EICR service and we will scope the board work from the findings.
RCD, RCBO and surge protection explained
Three pieces of equipment do the protective work in a modern board, and it is worth knowing which is which before you choose a specification.
- MCB (miniature circuit breaker). Protects the cable from overload and short circuit. It is the direct replacement for the old rewirable fuse and it resets with a switch rather than a length of fuse wire.
- RCD (residual current device). Protects people. It detects current leaking to earth — through a person, or through damaged insulation — and disconnects in milliseconds. A dual-RCD board splits the circuits into two banks, each behind one RCD.
- RCBO. Both functions in a single device, fitted per circuit. The advantage is isolation: a fault on the garden socket trips the garden socket only, instead of taking out half the property including the freezer and the boiler.
- SPD (surge protection device). Clamps transient overvoltages from lightning or switching events on the network before they reach televisions, computers, boiler controls and heat pumps.
For a rental property we normally recommend a full RCBO board. It costs more than a dual-RCD arrangement, but it dramatically reduces the number of out-of-hours calls where a tenant has lost power to everything because of one faulty appliance.
What a fuse box installation costs in London
Our prices start at £580.00 for a 6-way board, which suits most flats and smaller houses, and £680.00 for a 6-10 way board, which is the usual choice for a three or four bedroom property with a shower circuit, a cooker circuit and an outbuilding. Larger and bespoke boards are quoted on request once we know the circuit count.
The price covers the unit, the labour, the isolation and reconnection of every circuit, full testing and the certification. What it does not cover is pre-existing faults in the fixed wiring. We test each circuit before it is connected to the new board, and if a circuit has failed insulation resistance or a broken earth it has to be put right before it can be energised safely. Anything of that kind is quoted in writing before we proceed.
That is the honest answer to the question everybody asks, and it is why we test first rather than after. A new board on top of defective wiring simply trips, and the fault was there all along.
What a Fuse Box Installation Includes, Step by Step
1. Survey and Circuit Schedule
Before anything is ordered we establish how many circuits the property actually has, what each one serves, and whether the incoming supply arrangement is TN-S, TN-C-S or TT. That determines the board size, the protective device ratings and whether additional earthing work is needed.
2. Safe Isolation
The supply is isolated at the main switch and proved dead with an approved voltage indicator that is itself proved before and after use. Where the meter tails have to be disconnected, we work to the supplier’s requirements and reseal correctly.
3. Removing the Old Board
The existing unit and any wooden backboard are taken off the wall. If the mounting surface is combustible, a fire-resistant board goes on first. Cable tails that are too short to reach the new terminals are extended properly in an accessible enclosure, never buried.
4. Dead Testing Every Circuit
This is the stage that protects you. We measure continuity of protective conductors, ring final circuit continuity, insulation resistance and polarity on each circuit. A circuit with degraded insulation is identified here, before it is connected to a device that will simply trip.
5. Fitting and Terminating
The new metal unit is mounted, the main switch and protective devices are installed to the agreed specification, and each circuit is terminated to the correct torque setting. Every way is labelled so anyone can identify what a switch controls without guesswork.
6. Live Testing and Certification
Power is restored and we measure earth fault loop impedance and RCD disconnection times on every device, confirming they operate within the times BS 7671 requires. The readings are recorded on your Electrical Installation Certificate and the Part P notification is submitted.
Preparing For Your Installation Day
Preparing for your fuse box installation
The power is off for most of the working day, so a little preparation makes the difference between a smooth visit and a frustrating one:
- Plan around the outage. Expect four to six hours without electricity. Leave freezers closed, charge phones and laptops beforehand, and if anyone in the property relies on powered medical equipment, tell us when you book so we can arrange a temporary supply.
- Clear the board and the meter. We need working room in front of the existing board and access to the meter and the main isolator. Coats, shoes and storage in the cupboard all have to come out first.
- Warn the tenant properly. Written notice of at least 24 hours is the usual standard, and a tenant who knows the power will be off all day is far more likely to give access without difficulty.
- Find the last inspection report. It tells the electrician which circuits already carry observations and saves time hunting for faults on the day.
- Think about the alarm and the boiler. Intruder alarms, smart heating controls and some door entry systems need resetting once power returns; have the codes to hand.
If the property is empty and you cannot be there, we collect keys from an agent, a concierge or a neighbour. Say so at the time of booking and we will build it into the appointment.
What happens on installation day
The sequence is always the same, and it exists to make sure nothing is energised until it has been proved safe.
The electrician arrives, shows identification, and confirms the circuit schedule with you. The supply is isolated at the main switch and, where the seal allows, the installation is disconnected from the meter. The old board comes off the wall along with any wooden backboard behind it, and a fire-resistant board is fitted if the surface needs one.
Every circuit is then tested dead: continuity of protective conductors, ring final circuit continuity, insulation resistance and polarity. That is the stage where existing faults show up, and it is the point at which we speak to you if something needs quoting. Circuits that pass are terminated into the new unit and labelled clearly.
With the board complete, the supply is restored and the live tests are carried out — earth fault loop impedance and RCD trip times on every protective device. The results go onto the certificate, the schedule of circuits is fixed inside the cover, and the electrician walks you through what each switch does before leaving.
Certificates, Testing and What Comes Next
After your fuse box installation: certificates and testing
Two documents come out of the job and they do different things. The Electrical Installation Certificate (EIC) is the technical record: it names the person responsible for the design, construction, inspection and testing, lists every circuit, and records the measured values for each test. Keep it permanently, because the next inspector will compare their readings against it.
The Building Regulations compliance certificate follows from the competent person scheme once the Part P notification has been processed. It is the document a buyer’s solicitor asks for, and it is much easier to file it now than to reconstruct it in five years’ time.
A new board does not reset your inspection cycle. A rental property still needs a periodic report at least every five years, and the certificate for the board covers the board and the circuits as tested on the day — not the condition of the wiring for the rest of its life. If a circuit trips repeatedly after the work, that is nearly always the wiring or an appliance telling you something, and it is worth investigating rather than resetting.
How it fits with your other landlord checks
Electrical work rarely happens in isolation. Most London landlords are juggling four compliance documents at once, and the board upgrade normally arrives as the outcome of one of them.
- Electrical. The five-year inspection is the trigger for most upgrades. Book the EICR certificate first and let the findings decide the specification.
- Gas. An annual gas safety certificate runs on a twelve-month cycle and is a separate legal duty entirely.
- Appliances. Where you supply white goods or furnish the property, PAT testing covers the portable items that the fixed-wiring inspection does not.
- Energy. An EPC lasts ten years, and rented homes in England must currently meet at least band E under the minimum energy efficiency standards.
Booking two or three of these on one visit saves an access appointment and a tenant’s afternoon. Tell us what is due when you book online and we will put them on the same slot wherever the engineer qualifications allow.
Frequently Asked Questions
Clear answers about the work itself, the certificates you receive and what happens if we find a fault.
A typical consumer unit replacement takes between 4 to 6 hours. During this time the power to the property will be turned off, so please plan accordingly (for example, freezer contents and home working). Larger properties with more circuits to test take longer.
Yes. Upon completion and testing you will receive an Electrical Installation Certificate (EIC) recording every test result. We also notify Building Control under Part P on your behalf, and the compliance certificate follows from the scheme provider.
No. The price covers the unit replacement and testing. We test your circuits before connecting the new board. If we find critical faults that make the new unit unsafe or cause it to trip, these must be fixed. We will provide a quote in writing for any remedial work required.
Current regulations require consumer units in domestic premises to be made of non-combustible material, in practice steel, so that any fire starting within the enclosure is contained rather than spreading into a hallway or cupboard.
An RCBO is a modern safety device that combines overcurrent protection (MCB) and earth fault protection (RCD) in one module. The benefit is that if one circuit trips it does not cut power to the other circuits, unlike older dual-RCD boards.
We ensure the unit is mounted securely. However, if the new unit is smaller than the old wooden backboard there may be some gaps or decorating required. We do not plaster or paint.
A Surge Protection Device protects sensitive electronics such as televisions, computers and boiler controls from transient voltage spikes. Protection against transient overvoltages now has to be considered for most new installations.
It removes the observations relating to the board itself, which is the most common reason for an unsatisfactory result. It does not cure faults in the fixed wiring elsewhere in the property, which is why we test every circuit before connecting it.
Our Accreditations
Recognized and certified by the UK's leading property safety bodies.
Ready to upgrade your consumer unit?
Fixed prices from £580.00, metal 18th Edition boards, full testing and your certificate on completion.
Fuse Box Installation & Consumer Unit Replacement Service Areas in London
We cover all 32 London boroughs, including North London, East London, South London, West London, and central districts. Fast dispatch for: