Consumer Unit & Fuse Board Upgrades

Signs You Need an Upgrade

The clearest sign is a fuse board that still uses rewireable fuses, the type where a length of fuse wire physically breaks the circuit when it's overloaded. Beyond that, common triggers include:

• A failed EICR flagging the absence of RCD protection, one of the most common C2 findings on older properties in the area, requiring remediation within 28 days

• Your insurer or mortgage lender requesting confirmation of RCD protection as a condition of cover or lending

• Frequent tripping or the need to reset your consumer unit regularly

• You're planning a rewire or adding new circuits, such as an EV charger

• Battery storage and solar-ready consumer units are affected by the current wiring regulations

What's Included

A modern consumer unit replaces old fuse wire with circuit breakers and RCD protection that trips automatically and can be reset with the flick of a switch. Every installation includes:

• Full removal of the old board and replacement with a modern, metal-clad consumer unit

• RCBO protection fitted per circuit, reducing nuisance tripping compared to a single shared RCD

• A surge protection device (SPD) to safeguard appliances and electronics from power spikes

• All circuits individually tested before and after installation

• A NAPIT completion certificate issued the same day, suitable for insurance records, mortgage files or a property sale

Understanding Your Consumer Unit

Not sure what each part of your consumer unit actually does? The main switch cuts power to the whole property. MCBs (Miniature Circuit Breakers) protect individual circuits from overload. RCDs (Residual Current Devices) detect earth faults and cut power within milliseconds to prevent electric shock. RCBOs combine both functions on a single circuit, which is why they cause far less nuisance tripping than an older shared-RCD setup.

If a switch keeps tripping repeatedly, that's usually a genuine fault rather than something to keep forcing back on.

What It Costs

Consumer unit and fuse board replacement starts from £600 for a standard domestic installation with modern RCBO and surge protection. The exact price depends on the number of circuits and the condition of your existing wiring. We always confirm a fixed price after a quick site survey, before any work begins.

How Long It Takes

Most standard domestic upgrades take between 4 and 6 hours, including installation, full circuit testing and certification. Larger properties or more complex installations may take longer, and we'll confirm timings after the initial survey.

Areas We Cover

We install and replace consumer units and fuse boards across Horley, Crawley, Reigate, Redhill and the surrounding Surrey and West Sussex area, for homeowners, landlords and businesses alike, including commercial and landlord properties.

Consumer Unit & Fuse Board Upgrades Across Horley, Redhill, Reigate & Crawley

Consumer Unit Upgrades in Horley

A lot of the older properties near Horley town centre are still running on original rewireable fuse boards from decades ago. We upgraded one recently for a couple who'd just found out their mortgage lender wouldn't complete without it, since the survey flagged the old board as a fail. Six hours start to finish, and they had a proper RCBO board with surge protection by the end of the day, certificate included.

Consumer Unit Upgrades in Redhill

Redhill's converted flats throw up a particular problem: shared supplies and boards that were never really designed for how the building's used now. We upgraded a board in a converted Victorian house last month where the landlord had three separate tenancies all pulling off one ageing consumer unit. Splitting it out properly, with dedicated protection for each flat, fixed a run of nuisance trips that had been going on for months.

Consumer Unit Upgrades in Reigate

Reigate's period homes often still have their original board tucked away somewhere awkward, under the stairs, in a cupboard that's clearly been built around it since. One Reigate job involved a board so old the customer genuinely didn't know it wasn't safe until we pointed out it had no RCD protection at all. Straightforward upgrade, but a useful reminder that "it's never tripped" isn't the same as "it's safe."

Consumer Unit Upgrades in Crawley

Crawley's newer estates are usually in better shape, but we still get call outs where an extension or loft conversion has been added to a board that was only ever sized for the original house. We upgraded one in Crawley where a home office and an EV charger had been bolted onto an old board that simply didn't have the capacity, tripping constantly under load. New board, sized properly for how the house is actually used now.

Frequently Asked Questions

How long does it take to replace a fuse box?

Typically 4 to 6 hours for a standard domestic upgrade, including installation, full circuit testing and same-day certification.

What does a consumer unit replacement cost?

From £600 for a standard domestic installation. Costs vary depending on the number of circuits and the condition of existing wiring, confirmed with a fixed-price quote after a site survey.

Will I get a certificate for the work?

Yes. As NAPIT-accredited contractors, we issue an Electrical Installation Certificate and notify Local Authority Building Control on your behalf where required.

How do I know if my consumer unit needs upgrading?

The clearest sign is a fuse board still using rewireable fuses, or a lack of RCD protection. A failed EICR, a request from your insurer or mortgage lender, or frequent tripping are all strong indicators too.

Why Does My Consumer Unit Switch Keep Tripping?

This is one of the most common calls I get, and it's rarely as worrying as it feels in the moment. When people say their "switch unit" or "unit switch" keeps tripping, they're usually describing one of two things - and knowing which one matters, because the fix is completely different.

If it's a single switch tripping - that's almost always an RCBO or MCB doing exactly its job. Something on that specific circuit (a faulty appliance, a damp outdoor socket, a fridge on its last legs) is drawing current it shouldn't be, and the switch is protecting you from it. Annoying, yes. Dangerous to ignore, also yes.

If everything trips at once - that points to a shared RCD covering multiple circuits, which is common in older consumer units built before RCBOs became standard on every circuit. One faulty appliance anywhere on that shared group can knock out your whole downstairs, even though only one circuit is actually at fault. It's one of the main reasons I recommend upgrading to individual RCBOs on new installs - it isolates the problem instead of taking the whole board down with it.

Either way, the switch tripping isn't the problem. It's telling you there is one. If it trips once and resets fine, keep an eye on it. If it trips repeatedly, or won't reset at all, that's worth getting looked at properly rather than leaving it switched off - a repeatedly tripping switch is doing its job, not malfunctioning.