Electrical advice · Hertfordshire
How Much Does Consumer Unit Replacement Cost?
There's no single price for replacing a consumer unit. The cost depends on your property, the board you need and the condition of the wiring it's connected to. Here's what makes the difference.
What affects the cost?
Number of circuits
A small flat may have six or seven circuits; a large house with an extension, outbuilding and EV charger can have many more. More circuits means a larger board, more protective devices and more testing.
Type and specification of consumer unit
Boards vary in quality and features. Modern domestic consumer units have metal enclosures, and some installations benefit from surge protection or arc fault detection devices. Each of these affects the price.
RCD and RCBO protection
A board using shared RCDs is generally cheaper than one with an individual RCBO on every circuit. RCBOs cost more, but a fault on one circuit won't take out others — worth weighing up if you work from home or rely on a freezer or medical equipment.
Condition of the existing installation
If the main earthing arrangement or the protective bonding to gas and water pipes is missing or inadequate, it will need upgrading before a new board can be certified.
Testing and certification
Proper testing of every circuit, notification under Part P and the issue of certificates are part of the job — not optional extras. They take time and should be included in any quote.
Additional remedial work
Modern RCD protection often exposes faults that an old fuse box tolerated, such as damaged cables or borrowed neutrals between circuits. These need to be found and put right, which can add to the cost.
Why the installation needs assessing first
Because so much depends on what's behind the board, an accurate quotation normally requires an electrician to look at the installation. A figure given without seeing it can easily change once work begins.
Replacing an old fuse box vs upgrading a modern board
Replacing a fuse box with rewirable fuses is usually a bigger job: earthing and bonding are more likely to need work, and older circuits are more likely to show faults when tested. Swapping a relatively modern consumer unit — for example to add capacity or switch to RCBOs — is often more straightforward.
Why the cheapest quote may not be comparable
Two quotes for “a new consumer unit” can describe very different jobs. When comparing, check:
- Whether the board uses RCDs or RCBOs, and whether surge protection is included
- Whether earthing and bonding upgrades are included or priced separately
- That full testing, notification and certification are included
- That the electrician is registered with a scheme such as NAPIT
Related guides
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