The short answer
Replacing a consumer unit is worth doing when it has no RCD protection (which is the protection that cuts the power fast enough to prevent most fatal electric shocks), still uses old rewireable fuses, shows heat damage or persistent faults, or has failed an EICR with C1 or C2 codes. A modern RCBO board also isolates faults to a single circuit rather than tripping half the house. For some insurers, an unprotected older board is a material risk that affects cover. The work typically costs £500–£1,200 installed and adds a verifiable safety improvement rather than a cosmetic one. It is not worth replacing a board that already has RCD or RCBO protection, is undamaged and is passing its periodic tests — age alone does not make a sound, protected board unsafe.
The 'is it worth it' question really has two strands: whether the safety improvement is genuine and whether the money spent translates into other benefits like insurance cover or property saleability. Here is an honest assessment of both.
Key considerations
- No RCD protectiongenuine safety risk worth addressing
- Rewireable fusesno shock protection; worth upgrading
- Passing modern testsmay not need replacing yet
- Typical cost~£500–£1,200 installed
- Property salebuyers and conveyancers scrutinise older boards
When replacing is genuinely worthwhile
There are clear cases where a consumer unit replacement delivers a real and verifiable improvement:
- No RCD or RCBO protection: an RCD (residual current device) detects current leaking to earth and disconnects in milliseconds — fast enough to prevent many fatal shocks. An old board with only rewireable fuses, MCBs or an older main switch has no such protection. This is a genuine safety gap, not a theoretical one. Modern consumer units meet this requirement, and BS 7671 has required RCD protection on most circuits for some years.
- Old rewireable fuses: these protect against overload by melting, but they offer no residual-current protection and their condition is hard to assess without testing the fuse wire. A modern MCB or RCBO trips and resets; there is no ambiguity about whether it has operated.
- Heat damage, burning smell or persistent faults: a board showing scorch marks, an unusual smell or repeated unexplained tripping is telling you something is wrong. A board in this condition needs inspection and likely replacement regardless of age.
- EICR codes C1 or C2: a periodic inspection (EICR) that returns a C1 (danger present) or C2 (potentially dangerous) code means remedial work is required before the installation can be signed off. A C2 at the consumer unit commonly points to a board replacement as the appropriate remedy.
- Adding a major new circuit: an EV charger, an extension or an outbuilding sub-feed may require a board that can accommodate that load safely, which an old or full board cannot.
| Situation | Worth replacing? | Reason |
|---|---|---|
| No RCD/RCBO protection | Yes | Genuine shock-protection gap |
| Old rewireable fuses | Yes | No residual-current protection |
| Heat damage / burning smell | Yes | Active safety concern |
| EICR C1 or C2 at the board | Yes | Remedial work required |
| Adding EV charger / extension circuit | Often yes | Board may be full or inadequate |
| Modern board, protected, no faults | Not necessarily | Sound board does not need replacing |
General guidance. A registered electrician's inspection confirms the right course of action for your installation.
The insurance and property value angle
Two further practical arguments are sometimes made for replacing a consumer unit:
Insurance: some home insurers ask about the type of consumer unit or age of wiring on the application form. An older board without RCD protection can be flagged as a material fact. If your insurer knows about an unprotected board and you do not disclose it or correct it, that can affect a claim. Check your policy terms; a registered electrician's letter confirming the board type can help if there is any ambiguity.
Property sale: when a property is sold, conveyancers and buyers' surveyors typically ask about electrical condition. An older consumer unit without RCD protection, or a board with known faults, can come up in the survey or the legal enquiries. Having a modern, certified board with a current EIC removes one source of negotiation or delay. That said, replacing a sound board purely to add marginal value to a sale is a decision for the seller — there is no fixed 'value added' figure, and the cost should be weighed against the sale price and buyer expectations for the type of property.
When it probably is not worth replacing
A consumer unit that already has RCD or RCBO protection on all circuits, is undamaged, not overheating, not tripping unexpectedly, and has passed its most recent EICR does not need replacing simply because it is a few years old or looks dated. Modern consumer units have a long service life when they are correctly installed and maintained. The argument 'it's old so it should go' is not supported by the wiring regulations, which are concerned with safety and condition, not age alone.
Be cautious of any pressure to replace a board without an inspection finding a specific reason to do so. A periodic inspection (EICR) by a registered electrician is the correct way to establish whether any action is needed.
Frequently asked questions
Does replacing a consumer unit add value to a house?
There is no fixed figure for value added, but a property with a modern, certified consumer unit and current EIC is less likely to produce issues in a survey or conveyancing process. Whether that translates into price is property and market dependent. The clearer argument for replacement is safety, not purely financial return.
Will my home insurance be affected by an old consumer unit?
Some insurers ask about electrical installation on the application form, and an older unprotected board can be a material fact you are obliged to disclose. Check your policy wording. A registered electrician's confirmation of the board's condition can support any declaration you make.
How do I know if my consumer unit already has RCD protection?
Look for a test button on the board labelled 'Test' or 'T'. Modern boards typically have one or more RCDs visible as wider switches, or individual RCBOs per circuit. If you are unsure, a registered electrician can check and tell you within minutes. Do not press the test button without knowing whether you have sensitive equipment (medical devices, fish tanks) on circuits that may be affected.
Sources & further reading
- Electrical Safety First — replacing a consumer unit best practice guide
- Checkatrade — cost of replacing a fuse box / consumer unit
- gov.uk — Part P: electrical safety in dwellings
Figures on this page are typical UK ranges drawn from published sources and depend on your specific property and installation. They are guidance, not a quotation.