No RCD protection
Older units using only fuses or MCBs give no protection against electric shock from an earth fault, a gap modern boards close with RCDs or RCBOs.

An outdated or unsafe fuse board is replaced with a modern, correctly protected consumer unit, tested to current standards and certified on completion.
Rated 5.0 on Google · 12+ years in the trade · NAPIT registered
NAPIT registered
Work certified to current standards
18th Edition
BS 7671 wiring regulations
£5m / £10m cover
Public and employer's liability
5.0 on Google
Rated by local customers
12+ years
Experience in the trade
Overview
The consumer unit, sometimes still called a fuse box, is the point where a property's incoming electricity supply is divided into individual circuits and protected. Replacing it means fitting a new unit with correctly rated breakers and RCD or RCBO protection, connecting each existing circuit to it, and testing the whole arrangement before it goes back into service.
This work is typically needed when an EICR identifies a consumer unit as a safety concern, when an older unit uses rewireable fuses or lacks RCD protection altogether, when a property is being renovated or rewired and the board needs to match the new circuit count, or simply when an existing unit is showing signs of wear such as scorching, cracked casings or unreliable breakers.
Because the consumer unit is central to the safety of every circuit in the property, this is notifiable work under Part P. As a NAPIT registered contractor, Hardi Electrical LTD notifies building control directly where required and issues an Electrical Installation Certificate once testing is complete.
Swapping an outdated fuse box for a modern consumer unit with RCD or RCBO protection throughout.
Fitting a board sized correctly for a new or expanded set of circuits during a rewire or renovation.
Replacing a unit that's tripping unpredictably, overheating, or has been flagged by an EICR.
Moving to a metal-clad consumer unit where current guidance calls for it, depending on the property's construction.
What happens if it is left
Consumer units don't announce their own failure. A board can look intact from the outside while offering little real protection, which is exactly why EICRs so often flag them.
Older units using only fuses or MCBs give no protection against electric shock from an earth fault, a gap modern boards close with RCDs or RCBOs.
Fuse wire can be replaced with the wrong rating by well-meaning DIY, removing the circuit protection it's meant to provide.
Loose or corroded terminations inside an old board generate heat, and scorching around breakers is a sign the unit needs urgent attention.
Older plastic consumer units in some property layouts don't meet the level of fire containment now expected, particularly on escape routes.
Our process
Replacing a consumer unit means the property is briefly without power while the swap happens, so the work is planned to keep that downtime as short as reasonably possible.
The existing board, circuits and any known faults are reviewed to establish the right specification for the replacement.
A written quote is provided based on the number of circuits and the unit specified, priced individually for the property.
The supply is safely isolated and the old consumer unit is removed.
The new board is fitted and each existing circuit is connected, with RCD or RCBO protection allocated correctly across circuits.
Every circuit is tested from the new board, with an Electrical Installation Certificate issued and building control notified directly where the work is notifiable.
What you get
Most domestic consumer unit replacements are completed within a single working day.
RCD or RCBO protection across circuits closes gaps that older boards simply don't cover.
A correctly specified modern unit is built to give many years of reliable protection.
Every replacement is priced individually once the number of circuits and specification are known.
RCBOs allow individual circuits to be protected separately, so a fault on one circuit doesn't take out the whole house.
An EIC and, where required, building control notification give a clear record for insurers, buyers and future electricians.
In detail
A dual-RCD board splits circuits across two RCDs, so a fault on one circuit only affects the circuits sharing that RCD rather than the whole property. An RCBO-based board gives each circuit its own combined overcurrent and residual current protection, which reduces nuisance tripping further and is often the preferred specification where budget and circuit count allow.
The right choice depends on the number of circuits, how the property is used, and what's practical for the existing installation, which is assessed during the site visit rather than assumed in advance.
Consumer units are available in various enclosure types, and current guidance on fire-resistant construction is considered when specifying a replacement, particularly in relation to where the unit is sited within the property, such as under stairs or on an escape route.
Where a consumer unit replacement happens alongside a full or partial rewire, the board is sized for the final circuit count rather than the existing one, so there's no need to revisit the installation shortly after completion. Where it's a standalone replacement, the existing circuits are assessed to confirm they're suitable to connect to the new board as they are.
Most replacements are for the main household consumer unit, but sub-boards feeding garages, outbuildings or extensions are assessed on the same basis, since they carry the same safety considerations as the main board.
Recent work
Scroll across to see more of our completed work.







Common questions
It depends on the number of circuits and the specification needed, so a site visit is used to assess this before a written quote is provided.
Most domestic replacements are completed in a single working day, including testing and certification.
A site visit and assessment lead to a written quote, then isolation, fitting of the new unit, reconnection of circuits, and full testing and certification.
Yes. An Electrical Installation Certificate is issued once testing is complete, and building control is notified directly where the work is notifiable.
A correctly specified and installed unit is designed to provide reliable protection for many years, though periodic inspection and testing helps confirm it remains in good working order.
Once the site visit and quote are agreed, work is scheduled Monday to Friday, 8am to 5pm. Call 07730 498814 to discuss timing.
Yes, consumer unit replacements are carried out across Locks Heath, Warsash, Hedge End, Southampton, Fareham, Titchfield, Park Gate and Whiteley.
The supply needs to be isolated while the old unit is removed and the new one connected, so there's a period without power, kept as short as practically possible during the visit.
Related services
Next step
We'll assess your existing board and circuits, then provide a written quote. Call 07730 498814 or send an enquiry.
hardielectrical@outlook.com
Monday to Friday, 8am–5pm
NAPIT registered · £5m public liability · £10m employer’s liability