Consumer unit & fuse board upgrades, done in a single visit.
If your fuse board still runs on rewireable fuse wire, sits in a plastic enclosure or has no RCD protection, it is behind the current standard. We replace it with a metal, 18th-Edition RCBO board — isolated, installed, tested and certified in one day.
Signs your board has had its day.
- Rewireable fuses or cartridge fuses. Old fuse wire offers no fine overload protection and none of the shock protection an RCD provides.
- A plastic or wooden enclosure. Since the January 2016 amendment, consumer units in domestic premises must have a non-combustible — typically metal — enclosure.
- No RCD protection. Without residual current protection there is no automatic disconnection in the event of an earth fault or contact with a live part.
- Frequent nuisance tripping. On a shared RCD, one minor fault takes out half the house. It points to a board that can no longer discriminate properly.
- A C2 on your EICR. An unsatisfactory report often traces back to the board itself — inadequate protection is a common potentially-dangerous observation.
- You're adding load. An EV charger, electric shower or an extension needs spare ways and modern protection the old board simply cannot supply.
What an 18th-Edition unit actually gives you.
- A metal enclosure. Non-combustible steel that contains a fault rather than feeding it — the requirement for domestic premises since the 2016 amendment.
- An RCBO on every circuit. Each way gets its own combined overcurrent and RCD protection, so a single fault isolates only its own circuit — not the whole board.
- A Surge Protection Device. Under Amendment 2 an SPD is now the default requirement, guarding sensitive electronics against transient overvoltage from the grid or nearby strikes.
- A clearly labelled main switch. One accessible point of isolation, with every circuit identified so you always know exactly what you are switching off.
The older split-load board shared two RCDs across all the circuits. A single earth fault would drop everything on that RCD — half the house in the dark. RCBO-per-circuit ends that: the faulty circuit trips alone and the rest of the installation stays live.
One engineer, one day, one certificate.
Safe isolation
We agree the outage window, isolate the supply and prove dead before any work begins — the installation is made safe throughout.
Out with the old
The existing board is removed and each circuit is checked and re-terminated ready for the new unit and its protective devices.
New unit fitted
The metal RCBO board — with SPD and main switch — is installed, every circuit labelled and the enclosure sealed to standard.
Test & certify
Full dead and live testing, then your Electrical Installation Certificate — plus Part P notification to Building Control.
Expect the power off for part of the day; a typical swap runs 4–6 hours. Because we are a registered installer, notification to Building Control under Part P is handled for you with no separate council fee. The existing installation must pass testing — if we find a problem on a circuit, we quote any remedials before proceeding rather than certifying over a fault.
“Our 1990s board was tripping the whole flat every time the shower ran. Polarity fitted a metal RCBO unit with surge protection in an afternoon — power back on before the school run — and the certificate was in my inbox that evening.”
Board swaps, priced up front.
Indicative domestic prices including VAT, EIC and Part P notification. Confirmed after a quick survey; any pre-existing remedials are quoted separately first.
Dual-RCD board swap
- Metal 18th-Edition enclosure
- Split-load twin-RCD arrangement
- Full testing & EIC
- Part P notified, no council fee
Full RCBO board
- RCBO on every circuit
- One fault isolates one circuit
- Metal enclosure & labelled ways
- Full testing, EIC & notification
RCBO board + SPD
- Everything in the RCBO board
- Surge Protection Device fitted
- Amendment 2 default protection
- Full testing, EIC & notification
Straight answers before you book.
Not sure whether your board needs replacing? Call 0330 043 8871 or email info@polarityelectrics.com and speak to a qualified engineer.
Ask a questionDo I legally have to upgrade my consumer unit?
There is no blanket law forcing a swap on an existing installation, but a board that lacks RCD protection or sits in a combustible enclosure will often draw a C2 on an EICR, rendering the report unsatisfactory. For rented property that must be resolved, and any new board is fitted to the current standard regardless.
How long does the work take and will the power be off?
A typical domestic board swap takes 4–6 hours. The supply is isolated for part of the day while the old unit is removed and the new one installed and tested. We agree the outage window with you in advance so you can plan around it.
What's the difference between RCBOs and the older dual-RCD board?
A split-load board shares two RCDs across every circuit, so one earth fault trips a whole bank of circuits at once. An RCBO gives each circuit its own combined overcurrent and RCD protection, so a fault isolates only the affected circuit and the rest of the installation stays live.
Do I really need a Surge Protection Device?
Under Amendment 2 to BS 7671, an SPD is now the default requirement for most installations. It protects sensitive electronics — boilers, EV chargers, computers and TVs — from transient overvoltage caused by grid switching or nearby lightning. It can be omitted only where a documented risk assessment justifies it.
Will I get a certificate, and is Building Control notified?
Yes. Replacing a consumer unit is notifiable work, so you receive an Electrical Installation Certificate (EIC) and we notify Building Control under Part P. As a registered installer we self-certify, so there is no separate council fee to pay.
What if a circuit fails testing during the upgrade?
The existing installation must pass testing before we can certify the new board. If we identify a fault on a circuit — such as poor insulation resistance or an inadequate earth — we stop and quote the remedial work first rather than certifying over a defect. You approve any additional cost before we proceed.
A safer board, fitted and certified in a day.
Send us a photo of your current fuse board for a fixed quote — metal enclosure, RCBOs and SPD, installed by our own qualified engineers.
Book your survey