Do I Need a New Consumer Unit?

It is one of the most common questions homeowners ask when something goes wrong with their electrics — or when they are buying an older property and want to know what they are taking on. The consumer unit, also known as the fuse board or fuse box, is the heart of your home’s electrical installation. When it is working well, you never think about it. When it is not, you notice immediately.

So how do you know whether yours needs replacing? The answer depends on age, condition, safety features, and what your property demands of its electrical system. This guide covers everything you need to know — including the signs that a replacement is overdue, what a modern consumer unit gives you that an older one cannot, and what the process involves.

What Does a Consumer Unit Actually Do?

Your consumer unit is the distribution point for all the electrical circuits in your home. Electricity arrives from your supplier via the meter and enters the consumer unit, where it is split into individual circuits — lighting, sockets, kitchen, immersion heater, outdoor power, and so on. Each circuit is protected by either a fuse or a circuit breaker. If a fault develops on any circuit, the relevant fuse blows or circuit breaker trips, cutting the power to that circuit and protecting the rest of your installation.

Modern consumer units go further than this. They incorporate RCDs — residual current devices — which provide an additional layer of protection against electric shock by detecting tiny imbalances in current that indicate a fault. Older fuse boards often lack this protection entirely, which is one of the main reasons they are increasingly considered inadequate by modern safety standards.

Signs You May Need a New Consumer Unit

Not every fuse board needs immediate replacement, but there are clear indicators that yours may be due an upgrade. If any of the following apply to your property, it is worth having a qualified electrician carry out an assessment.

Your consumer unit is more than 25 years old

Consumer units have a finite working life. Components degrade, insulation deteriorates, and older designs simply do not meet the safety standards expected of a modern electrical installation. If your fuse board dates from the 1990s or earlier — or if you genuinely have no idea how old it is — that alone is a reason to have it inspected.

It uses rewirable fuses rather than circuit breakers

Older fuse boards use ceramic fuse carriers with fuse wire that physically melts when a circuit is overloaded. These are slower to respond than modern circuit breakers and offer no RCD protection. If your board has individual fuses rather than switches or toggle breakers, it is almost certainly due for replacement.

It has no RCD protection

RCD protection is now a requirement for most circuits under the 18th Edition Wiring Regulations (BS 7671) . An RCD trips within milliseconds of detecting a fault, which can be the difference between a minor incident and a fatal electric shock. Consumer units without RCD protection are not compliant with current regulations and represent a genuine safety risk.

Your circuit breakers or fuses keep tripping

A circuit breaker that trips occasionally is doing its job. One that trips repeatedly — or a fuse that keeps blowing — usually indicates an underlying fault on the circuit rather than a nuisance trip. This may be caused by a failing appliance, a wiring fault, or an overloaded circuit. In some cases it can indicate a failing consumer unit. Either way, repeated tripping warrants investigation by a qualified electrician.

The unit feels warm to the touch or shows scorch marks

A consumer unit should run cool. If yours feels warm, has any discolouration, scorch marks, or a burning smell around it, that is a serious warning sign. These are indicators of overheating, arcing, or loose connections — all of which require immediate attention. Do not ignore them.

You are having significant electrical work done

If you are rewiring part or all of your home, adding an EV charger, installing solar panels, or carrying out a major renovation, it often makes sense to replace the consumer unit at the same time — particularly if it is already ageing. It avoids the cost of returning to do it later and ensures the new installation is built around a compliant, modern board.

You are buying or selling a property

If an Electrical Installation Condition Report (EICR) has been carried out as part of a property transaction and the consumer unit has been flagged as requiring improvement or replacement, acting on that recommendation is important — both for safety and for the transaction itself. Many buyers and mortgage lenders will require remedial work to be completed before proceeding.

What Does a New Consumer Unit Give You?

Beyond addressing the safety concerns above, a modern consumer unit brings several practical benefits that older boards simply cannot provide.

Full RCD protection across all circuits

Current best practice — and the requirement under the 18th Edition Wiring Regulations — is to provide RCD protection for all circuits. Modern dual RCD or RCBO consumer units achieve this, giving every circuit in your home the protection that older boards lack entirely.

Metal enclosure as standard

Since 2016, consumer units installed in domestic properties must use a non-combustible enclosure — in practice, this means a metal housing. Older plastic-encased fuse boards do not meet this requirement. A metal consumer unit significantly reduces the risk of the unit itself contributing to a fire if an internal fault develops.

Capacity for modern electrical demands

The average home draws considerably more electricity than it did twenty years ago. More appliances, more circuits, electric vehicle chargers, heat pumps, home offices, and smart home systems all place demands on an electrical installation that older consumer units were never designed to handle. A modern board gives you the capacity and the circuit count to support your home as it actually is — not as it was in 1995.

Individual RCBO protection per circuit

Higher-specification consumer units use RCBOs — combined residual current and overcurrent devices — for each individual circuit. This means that if a fault develops on one circuit, only that circuit is affected. With a dual RCD board, a fault on one circuit can take down half the house. For households where losing lighting or refrigeration is a significant inconvenience — or a health risk — RCBO protection is worth considering seriously.

Does My Consumer Unit Need to Meet Any Regulations?

Yes. Any new consumer unit installed in the UK must comply with BS 7671, the 18th Edition IET Wiring Regulations, which was updated in 2022. The work must be carried out by a qualified electrician who is registered with a competent person scheme such as NAPIT or NICEIC. Registration with a competent person scheme allows the electrician to self-certify the work and issue a Building Regulations compliance certificate without requiring a separate inspection by the local authority.

At Portcullis Power Solutions, we are NAPIT-accredited. Every consumer unit installation we carry out is certified, compliant, and backed by the relevant documentation. You should never use an electrician who is unable to provide this certification — it leaves you without proof that the work meets legal requirements, which causes problems when you come to sell the property.

How Long Does a Consumer Unit Replacement Take?

In most properties, a consumer unit replacement takes between four and eight hours, depending on the size of the installation and the number of circuits involved. The power to the property will be off for the majority of this time, so it is worth planning the day around that. In some older properties where circuits need to be tested and documented before the new board can be commissioned, the work may extend into a second day.

Our domestic electrical services team will give you a clear timeline when they carry out your pre-installation survey, so there are no surprises on the day.

How Much Does a New Consumer Unit Cost?

Consumer unit replacement costs vary depending on the size of your property, the number of circuits, the type of unit specified, and whether any additional work is required to bring circuits up to standard at the same time. As a general guide, most domestic consumer unit replacements fall in the range of £400 to £900 for a standard installation. Properties with larger or more complex installations, or where additional remedial work is identified, will fall outside this range.

We provide fixed-price quotes following a survey, so you know exactly what you are committing to before any work begins. There are no hidden charges.

Can I Replace My Own Consumer Unit?

No — and this is not a grey area. Consumer unit replacement is notifiable work under Part P of the Building Regulations in England and Wales. It must be carried out by a qualified electrician registered with a competent person scheme. Attempting to replace a consumer unit yourself is illegal, will not be certifiable, will void your home insurance, and is genuinely dangerous. The supply side of a consumer unit remains live even when the main switch is off. This is not a DIY job under any circumstances.

We Cover Nantwich, Crewe and the Wider Cheshire Area

Portcullis Power Solutions is based in Wybunbury, minutes from Nantwich town centre, and covers Crewe, Sandbach, Middlewich, Audlem, and the wider Cheshire area. Whether you need a consumer unit assessment, a full replacement, or an EICR to establish the current condition of your installation , our qualified electricians can help. We also cover commercial and industrial properties requiring consumer unit or distribution board upgrades.

If you are unsure whether your consumer unit needs replacing, the most sensible first step is an honest assessment from a qualified electrician — not a sales call. We will tell you what we find and what we recommend, without pressure.