Consumer Unit Replacement Cost: £500–£1,200 (Fuse Board)

A consumer unit replacement typically costs £500–£800 for a standard dual RCD board, or £800–£1,200 for a full RCBO board — including the unit itself, labour, testing, an Electrical Installation Certificate, and Part P notification. Replacing a consumer unit (also called a fuse board or fuse box) is one of the most common jobs for domestic electricians, and this guide breaks down exactly what you are paying for and what factors affect the price.

For a broader overview of consumer unit types and technical details, see our comprehensive consumer unit guide. This page focuses specifically on costs, what is included, and how to make sure you are getting a fair price.

The total cost of a consumer unit replacement includes the unit itself, labour, testing, certification, and Part P notification. The type of board you choose is the biggest factor.

Dual RCD Split-Load Board (500-700 Pounds)

The most common and cost-effective option. The consumer unit has two RCDs, each protecting a bank of circuits. If a fault occurs, the affected RCD trips and all circuits on that bank lose power. This is acceptable under BS 7671 but less convenient than an RCBO board.

• ✓Unit cost: 80 to 150 pounds (metal, dual RCD)
• ✓Labour: 200 to 350 pounds (4-6 hours typical)
• ✓Testing and certification (EIC): included in labour
• ✓Part P notification: included (through competent person scheme)
• ✓Total typical cost: 500 to 700 pounds

Full RCBO Board (800-1,200 Pounds)

The premium option where every circuit has its own RCBO — combining overcurrent and RCD protection in one device. A fault on one circuit only trips that circuit; all others remain live. Increasingly considered best practice for domestic installations.

• ✓Unit cost: 150 to 250 pounds (metal, populated with RCBOs)
• ✓RCBOs cost more than MCBs (15-25 pounds each vs 5-8 pounds)
• ✓Labour: 250 to 400 pounds (slightly longer installation)
• ✓Testing and certification (EIC): included in labour
• ✓Part P notification: included (through competent person scheme)
• ✓Total typical cost: 800 to 1,200 pounds

A straightforward consumer unit replacement assumes the existing wiring is in reasonable condition and the earthing arrangement is adequate. Several factors can increase the total cost.

Common Additional Work

• ✓Earthing upgrades — upgrading the main earthing conductor or main bonding (100-300 pounds)
• ✓Supplementary bonding in bathrooms — if not already present (50-150 pounds)
• ✓Tails upgrade — replacing the meter tails between the meter and consumer unit (100-200 pounds)
• ✓Additional circuits — adding new circuits not previously present (150-300 pounds per circuit)
• ✓Remedial work — addressing defects found during testing (variable)
• ✓SPD (surge protection device) installation — increasingly recommended (80-150 pounds)

Regional Price Variations

Labour rates vary significantly across the UK. London and the South East are typically 20 to 30 percent higher than the national average. Rural areas may also see higher costs due to travel time. The material costs are broadly similar across the country — the main variable is labour.

For guidance on earthing and bonding requirements, see our dedicated guide.

Consumer unit replacement is always notifiable work under Part P of the Building Regulations (England and Wales). This means it must be carried out by a competent person scheme member who can self-certify, or the homeowner must notify building control and pay for an inspection (200-400 pounds).

What You Should Receive After the Work

• ✓An Electrical Installation Certificate (EIC) with test results
• ✓A Building Regulations Compliance Certificate (from the competent person scheme)
• ✓A circuit chart showing all circuits, their ratings, and which devices protect them
• ✓Confirmation that the RCD test button has been demonstrated to you

If the electrician does not issue an EIC or is not a member of a competent person scheme, the work is not compliant. This can cause problems when selling the property and may invalidate your home insurance. For more on certificates, see our electrical certificates explained guide.

Since January 2016, all new and replacement consumer units in domestic premises must be manufactured from non-combustible material — in practice, this means metal (steel). This requirement comes from Regulation 421.1.201, introduced by Amendment 3 to the 17th Edition and carried forward into the 18th Edition.

Key Points

• ✓All new and replacement consumer units in domestic premises must be metal
• ✓Existing plastic consumer units do not need to be replaced purely because they are plastic
• ✓The requirement applies to domestic premises only (not commercial or industrial)
• ✓The metal enclosure contains any fire that starts within the unit, preventing spread
• ✓All reputable manufacturers now produce metal consumer units as standard

For a deeper understanding of consumer unit types, regulations, and protection options, see our full consumer unit guide.

Not every consumer unit needs replacing. However, certain signs indicate that an upgrade is necessary or strongly recommended.

Definite Replacement Needed

• ✓Old rewireable fuse board with fuse wire instead of MCBs
• ✓No RCD protection on any circuits
• ✓Signs of overheating — discoloured terminals, melted plastic, burning smell
• ✓The board cannot accommodate additional circuits you need
• ✓An EICR has identified the consumer unit as a C2 (potentially dangerous) defect

Recommended Upgrade

• ✓Plastic consumer unit (current but no longer compliant for new installations)
• ✓Dual RCD board where nuisance tripping is causing frequent disruption
• ✓Insufficient circuits for the property needs (overloaded circuits)
• ✓No surge protection where recommended by BS 7671

If you are unsure whether your consumer unit needs replacing, the best course of action is to arrange an EICR (Electrical Installation Condition Report). This will identify any defects and tell you whether the consumer unit is satisfactory or needs attention.

Modern consumer units increasingly include provision for surge protection devices (SPDs). The 18th Edition introduced requirements for SPD installation in certain circumstances, and Amendment 2 strengthened these requirements further.

• ✓SPDs protect against transient overvoltages from lightning or switching events
• ✓Type 2 SPDs are the most common for domestic installations
• ✓Cost: typically 80 to 150 pounds for the device plus installation
• ✓Many new consumer units come with SPD provision built in
• ✓Under Regulation 443.4.1 (as amended), SPDs are required in most cases unless the owner declares the risk of damage tolerable — in practice they are fitted in most new domestic installations

When having a consumer unit replaced, it is worth discussing SPD installation with your electrician. Adding an SPD during a consumer unit replacement is far cheaper than retrofitting one later.

A standard consumer unit replacement typically takes 4 to 8 hours for a competent electrician. The process involves:

• ✓Isolating the supply and confirming safe isolation
• ✓Removing the old consumer unit and disconnecting all circuits
• ✓Installing the new metal consumer unit
• ✓Reconnecting all circuits with correct torque settings
• ✓Verifying polarity and circuit identification
• ✓Full testing in accordance with BS 7671
• ✓Issuing the Electrical Installation Certificate (EIC)
• ✓Demonstrating the RCD test button to the homeowner

The property will be without power during the changeover period, which is typically 2 to 4 hours. A good electrician will keep this interruption as short as possible and will advise you in advance so you can plan accordingly. If additional work is needed (earthing upgrades, additional circuits, remedial work), the job may extend to a full day.

Consumer unit replacement is often part of a larger house rewire, in which case the consumer unit is installed during the second fix stage.