How to move a consumer unit

Helpful video reference. This walkthrough from the Domestic Electricians Life UK channel, "Consumer unit relocation UK - what the job involves", covers the key stages of a board move including DNO co-ordination, cable extensions and the tests carried out before sign-off. Worth watching before you speak to an electrician so you know what to expect.

1. Understand what moving the board actually involves

A consumer unit relocation is not a lift-and-shift job. Every circuit cable in the building originates at the board. When the board moves, either each circuit cable must be long enough to follow it to the new position, or new cable must be run, or existing cable must be extended with a joint in an accessible enclosure.

Beyond the circuit work, the meter tails need extending or replacing. That section is the DNO's job to disconnect and an approved operator's responsibility to reconnect. Your electrician co-ordinates this on your behalf, which is why booking early matters and why giving a realistic date is important from the start.

2. Notify your DNO and plan the disconnection

The UK has six regional distribution network operators. Your postcode finds yours on the Energy Networks Association website in seconds. Contact their connections team and explain that you need the service disconnected and reconnected on a specific date for a consumer unit relocation.

Lead times vary. In some areas the wait is two or three weeks. In east Kent, UK Power Networks typically responds promptly, but give yourself at least a fortnight to avoid the job stalling halfway. Your electrician may handle the DNO application as part of the contract; ask when you get quotes, because that conversation needs to happen early.

3. Measure the circuit cable lengths

The electrician traces every circuit from the board to its first accessory or junction and records whether there is enough slack to reach the new position. In older homes where cables are buried in walls and run through floor voids, this can take most of a morning.

Circuits that fall short will need one of three things: new cable running all the way to the first junction, a joint in an accessible and clearly labelled enclosure, or in some cases a sub-board arrangement. Your electrician sets out the options and costs for each before starting work.

4. Prepare the new mounting position

Consumer units must be mounted on a Class O non-combustible backboard under BS 7671. Plywood is fine; bare plasterboard is not. Beyond the backboard, the location must tick several boxes:

• Accessible for maintenance and testing without removing permanent fixtures.
• Away from sinks, hot water cylinders, condensation-prone external walls and direct heat sources.
• At a height where the main switch is reachable in an emergency, typically between 1.4 m and 1.8 m from the floor.
• Positioned so circuit cables enter cleanly without sharp bends at the board knockouts.

If the new location is a flush recess or purpose-made cupboard, check the enclosure dimensions against the board size before anything is ordered. A recess that is 10 mm too narrow costs a day's work to sort out.

5. Isolate, label and disconnect circuits

With the main switch off and the DNO disconnection date confirmed, the electrician works through each circuit breaker, records what it supplies and labels every cable core before removing it. A photo of the board taken before any disconnection backs up the labels. Each circuit also gets a tag at the board end and at the first accessible point on the run.

Cables are extended or rerouted as needed, run in BS 7671 prescribed safe zones in walls and floors, and any joints are made in accessible Wago or similar maintenance enclosures, never concealed behind finished plasterboard.

6. Reinstall the consumer unit and connect circuits

The board goes onto its new backboard. Circuit conductors are connected: CPCs to the earth bar, neutrals to the neutral bar, line conductors to the MCBs or RCBOs. The main protective earth connection from the board to the incoming earthing terminal must be re-established with the correct conductor, usually 10 mm² green-and-yellow.

On a TN-C-S supply (PME earthing, which most urban UK properties have), the main protective bonding conductors run from the earth bar to the gas and water intake pipes. If the board moves significantly, these may need extending too, and the correct size under BS 7671 is typically 10 mm².

7. Dead test every circuit before the DNO arrives

With circuits wired but before the meter tails are connected, the electrician carries out a full set of dead tests under BS 7671 Chapter 61:

• Continuity of protective conductors: R1+R2 values recorded for every circuit.
• Insulation resistance at 500 V DC: should read at least 1 MΩ between live conductors and earth; healthy circuits read far higher.
• Polarity checks: live on the correct terminal at every socket, switch and fixed appliance connection.

Any circuit that fails is traced and put right before the DNO visit. Sending the network operator out to energise a board that then fails live testing is a wasted appointment and another week's delay.

8. DNO reconnection and live tests

Once dead tests are clear, the DNO attends to reconnect the service. With the supply live, the electrician carries out:

• Earth fault loop impedance (Zs) on each circuit, confirming the protective device will disconnect within the required time under a fault condition.
• Prospective fault current (PFC) at the board, confirming every MCB and RCBO is rated for the available fault current.
• RCD trip times: 30 mA devices must trip within 300 ms at 1×I_n and within 40 ms at 5×I_n.
• Functional tests across every circuit: lights on, sockets live, cooker working, shower responding.

On completion the electrician issues the Building Regulations Electrical Installation Certificate, which you keep with the house deeds.

When to call us

Board relocations are a regular part of kitchen and conversion projects in Sandwich and east Kent. Richard co-ordinates the DNO application, assesses every circuit, carries out the full test suite and issues the certificate. Get in touch early if building work is on the horizon: the DNO wait is usually the longest part of the job, so the sooner that conversation starts the better.