RMP Electrical: Services
Consumer unit / fuse board upgrades
Replace old fuse boards with modern 18th Edition consumer units, RCBO-protected.
Your consumer unit is the hub of your home's electrical system. Every circuit in the property runs through it. When it is out of date, the whole system is less safe than it should be, and most inspection certificates will flag it.
What a consumer unit upgrade involves
We isolate the supply, disconnect all existing circuits from the old unit, and reconnect them one by one to the new board. Each circuit gets a correctly rated breaker, RCD protection is fitted on all socket and lighting circuits, and the whole installation is tested before we restore power. You end up with a correctly labelled board showing exactly what controls what.
Most consumer unit swaps take between four and six hours on a standard three-bedroom house. Larger properties or those with a high circuit count may need a full day.
When you need a new consumer unit
The most common reasons we get called for a board replacement:
- Your property has failed an EICR because of missing RCD protection
- The existing board still uses rewireable or cartridge fuses rather than MCBs
- You are selling the house and a buyer's survey has flagged the board
- A landlord EICR has returned C2 observations about the consumer unit
- The board is full and you want to add a new circuit, such as for an EV charger
- The board is making a buzzing or humming sound, or has scorch marks
RCBO boards versus split-load boards
The current standard for consumer unit upgrades is either a split-load board (one RCD protecting half the circuits) or an RCBO board (individual protection on every circuit). We fit RCBO boards as standard where the budget allows. The reason: if one circuit trips, only that circuit goes off. With a split-load board, a fault on one circuit can take down everything on that side of the board.
For rental properties and HMOs in particular, an RCBO board significantly reduces the chance of a nuisance trip leaving a tenant without power.
What the 18th edition of the wiring regulations requires
BS 7671 18th edition, which came into force in 2019, introduced stricter requirements around RCD protection. Most circuits in a domestic property now require RCD protection, including lighting circuits, which were previously often left unprotected. A board that was compliant ten years ago may no longer meet current requirements.
We only fit consumer units that comply with BS 7671 18th edition. We do not fit units into plastic enclosures, which have been prohibited in new domestic installations since 2016 due to fire risk.
Part P certification
Consumer unit replacement is notifiable work under Part P of the Building Regulations. This means the work must either be carried out by a registered electrician (who self-certifies) or notified to the local building control department. We are registered to self-certify, so you receive a Part P completion certificate automatically. This is the document your solicitor will ask for during a property sale.
What you get at the end
- New consumer unit fitted and all circuits re-terminated
- Every circuit tested and labelled
- Electrical Installation Certificate issued
- Part P Building Regulations completion certificate
- Honest advice on anything else worth attending to on the day
Fixed price quoted before we start. No charge for the visit if we cannot proceed for any reason.
Common questions
- How long does a consumer unit replacement take?
- Four to six hours for most properties. Larger installations with many circuits, or properties where circuit access is difficult, may take a full day.
- What is the difference between a split-load and an RCBO board?
- A split-load board uses one or two RCDs covering groups of circuits. A fault on any circuit in a group trips the whole group. An RCBO board gives every circuit its own combined MCB and RCD, so a fault trips only that circuit and leaves everything else on.
- Does the work need to be certified?
- Yes. Consumer unit replacement is notifiable under Part P Building Regulations. We self-certify as registered competent persons, which carries the same legal standing as local authority building control approval.
- Will my existing circuits need retesting?
- We carry out a visual inspection and basic tests on the circuits before connecting them to the new board. A full periodic inspection is only required if we find specific concerns during that check.
- My RCD keeps tripping. Does that mean I need a new board?
- Not necessarily. A tripping RCD points to a fault on one of the circuits it protects. Diagnosing and fixing that fault is a separate job. In most cases only the affected circuit needs attention, and the board itself is fine.
From our guides
Do I Need a New Consumer Unit When Selling?
There is no legal requirement to replace a consumer unit before selling a property. But if the existing board generates C2 observations on the buyer's EICR, it can delay or derail the sale. Here is what to expect.
What Is RCD Protection and Why Does It Matter?
An RCD (residual current device) disconnects a circuit in 30 milliseconds if it detects a fault to earth. Properties without RCD protection on socket and bathroom circuits are at a higher risk of fatal electric shock.
Do I Need a Consumer Unit Upgrade?
Old fuse boxes can be a fire risk and won't pass an EICR. Here's how to tell if your consumer unit needs replacing, what the upgrade involves, and what it costs.
How quoting works
No hourly rates.
Fixed prices.
Every job is quoted individually so you know exactly what you're paying before any work starts.
Tell us about the job
Drop a quick message with what needs doing. A few details, a photo if you have one.
Get a fixed quote
We reply within the hour with a clear, fixed price. Quoted in writing. Locked in.
Price locked. Work starts.
Once you're happy, we book a time. The price you agreed is the price you pay.
Quotes are always free. All notifiable work properly certified to current Building Regulations.
What people say
Trusted across the Thames Valley.
“Came and installed outside sockets for me. Was a lovely guy, came on time and did a good job. The price was reasonable compared to some of the quotes I got from other companies. Would really recommend. Will call for work in the future as good tradespeople can be hard to find.”
Kirsty Pumfrey
Hayes
“Excellent experience with RMP Electrical. Changed an old tube light to a new LED strip, good price. Would use again.”
Chris Corthine
Hayes
“Reliable polite friendly service. Good value. Needed more electric plug sockets in all rooms. Was carried out with professional work and no mess left behind. Very impressed. Highly recommend.”
Sharon Nuro
Hayes
Make Ryan your
electrician.
Our phone is on, 7am to 8pm, 7 days a week. Free quotes and estimates: tell us about the job and we'll agree a fair price.