The consumer unit — often still called a fuse box — is the central point where a property’s electrical circuits connect and are protected. It’s what you go to when a circuit trips, and it’s the part of the installation most likely to raise questions as a property gets older: is it still doing its job properly, does it need replacing, or is a specific fault the real issue? If it’s reaching that point, this page explains when a consumer unit replacement makes sense and what affects the cost.
Voltify Contractors carries out consumer unit and fuse box work across East and South-East London, as part of our full range of electrical services. This page is here to help you understand what these terms mean, what typically leads to a replacement being considered, and what can affect the cost — so that if you do need work carried out, you know what you’re deciding on.
Consumer Unit or Fuse Box: Is There a Difference?
In everyday conversation, “fuse box” and “consumer unit” are usually used interchangeably to mean the same thing: the unit that houses the circuit breakers or fuses protecting each circuit in a property. Older properties may have a genuinely older-style fuse box with rewireable fuses; most consumer units installed in recent decades use circuit breakers and RCDs or RCBOs — safety devices that automatically cut power to a circuit if they detect a fault, such as current leaking to earth. This page covers work relating to both terms, since customers search for them interchangeably. If you’re not sure which type you have, our guide to consumer units vs fuse boxes explains how to tell them apart and why the difference matters.
Signs Your Consumer Unit May Need Professional Attention
A consumer unit doesn’t need to be replaced just because it’s old. That said, certain signs are worth having assessed by a professional:
- it still uses rewireable fuses (fuse wire) rather than circuit breakers;
- the casing is an older plastic type showing signs of heat damage, cracking or discolouration;
- circuits trip repeatedly without an identifiable external cause;
- there’s no RCD or RCBO protection on relevant circuits;
- the unit has been added to or altered informally over the years, with mismatched components;
- you’re planning an extension, rewire or major renovation and want the consumer unit assessed as part of that work.
None of these signs on their own automatically mean replacement is required — that’s a judgement made after inspecting the specific installation, not a blanket rule. For independent guidance on consumer unit safety, see Electrical Safety First.
Repair, Replacement, or Investigation First?
| Situation | Likely next step |
|---|---|
| The consumer unit trips repeatedly and the cause isn’t clear | Electrical Fault Finding, to establish the actual cause before deciding on the unit itself |
| The unit is old, uses fuse wire, or shows visible wear, and you want it assessed | Consumer Unit & Fuse Box Services (this page) |
| A specific breaker or component has failed but the rest of the unit is sound | Assessed on site — a single component repair may be possible rather than full replacement |
| You want a general safety assessment of the property’s electrics, not just the consumer unit | Electrical Testing & Inspection |
| There’s a burning smell, visible damage or the unit feels unsafe right now | Emergency Electrician |
Because a consumer unit sits at the centre of the whole installation, the right first step often depends on what’s actually found on inspection rather than what’s visible from the outside.
What Affects Consumer Unit Replacement Cost in London
Consumer unit replacement cost varies considerably between properties, and reputable quotes should reflect the actual job rather than a flat online price. Variables that genuinely affect scope and cost include:
- Number of circuits. More circuits generally means a larger unit and more work to test and connect each one.
- Condition of existing wiring. If cabling connected to the unit is found to be in poor condition or incompatible with modern protective devices, that can extend the scope of work.
- Access and location. A consumer unit in a straightforward, accessible location is quicker to work on than one in a tight cupboard, under stairs, or requiring additional access work.
- Remedial findings. Sometimes issues are only found once the existing unit is opened up — bad connections, outdated cabling, or non-standard previous work.
- Whether other work is being carried out at the same time, such as rewiring or an extension, which can change how the job is scoped.
The documented minimum call-out for Voltify Contractors’ work is £80 for the first hour; this figure relates to attendance and initial assessment and is not the price of a consumer unit replacement, which depends on the factors above and is confirmed after inspection.
What to Expect During a Consumer Unit Replacement
A consumer unit replacement typically starts with an on-site assessment of the existing installation before any firm scope or price is confirmed — this is standard practice given how much the job can vary between properties. Because the consumer unit controls power to the whole property, replacement work usually means the electricity supply to the property will need to be switched off for a period while the work is carried out; this is discussed and planned for in advance, not sprung on the day.
A Note on Certification and Inspection
Some searches around consumer units relate to formal testing, certification or periodic inspection (often referred to by its report name). Voltify Contractors’ approved service scope for this page does not cover issuing that kind of formal certification — see Electrical Testing & Inspection for what’s covered there, or contact us directly to discuss your specific requirement.
Areas We Cover for Consumer Unit & Fuse Box Work
Voltify Contractors carries out consumer unit and fuse box work across East and South-East London, including Canary Wharf & E14, Stratford & E15, Bow & E3, Canning Town & E16, Greenwich & SE10, Woolwich & SE18 and Barking & IG11. See the areas we cover for full details.
