Updated
Signs Your Fuse Box Needs Upgrading
Your fuse box is showing signs that it is outdated and no longer providing adequate protection.
Find an electrician
What's happening?
A fuse box that needs upgrading may still be working, but it is not providing the level of protection required by modern standards. Common signs include rewirable fuses, no RCD protection, frequent tripping, inability to add new circuits, physical damage, or having failed an EICR. Upgrading to a modern consumer unit brings your installation in line with the current 18th Edition of BS 7671.
What usually causes it?
- Board is over 25 years old and uses outdated protection devices
- EICR has identified the consumer unit as unsatisfactory (C2 or C3 codes)
- No space to add circuits for new installations (EV charger, extension, etc.)
- RCD protection is absent or only partial
- Board has been modified with external add-on RCDs or secondary fuse boxes
- Physical damage, burn marks, or corrosion visible on the board
Is it dangerous?
An outdated fuse box is a passive danger — it may work under normal conditions but fail to protect you adequately when a fault occurs. Without RCD protection, earth faults that could cause lethal electric shock may not be detected. Rewirable fuses can be fitted with incorrect fuse wire, defeating overcurrent protection.
Can I fix it myself?
No. Consumer unit replacement is notifiable under Part P of the Building Regulations and must be carried out by a registered electrician. The work requires isolating the mains supply, which involves working near live components at the meter.
When should you call an electrician?
Contact an electrician for a quote if you recognise any of the signs above. Many electricians offer free assessments. An upgrade is particularly advisable if you are adding circuits, letting a property, selling a property, or have had an EICR recommend it.
What will the electrician actually do?
- Survey the existing installation to specify the correct replacement board
- Isolate the supply and remove the old fuse box
- Install a new 18th Edition consumer unit with MCBs and RCD/RCBO protection
- Reconnect all circuits and test each one to BS 7671 standards
- Issue an Electrical Installation Certificate
- Notify Building Control (included in the registration scheme)
What will it cost to fix?
£350–£650
Standard consumer unit upgrade with testing and certification. RCBO boards cost £100–£200 more than dual-RCD boards. Add £50–£100 if earthing and bonding needs upgrading.
Find an electricianFrequently asked questions
We’re happy to answer all your questions.
How often should a fuse box be replaced?
There is no fixed lifespan, but consumer units installed before the mid-1990s are likely due for replacement. The key factor is whether it provides RCD protection and complies with current regulations.
What is the difference between a fuse box and a consumer unit?
They serve the same purpose, but a fuse box uses fuses while a consumer unit uses MCBs and RCDs. The term consumer unit is the modern, correct term. Many people still say fuse box out of habit.
Do I need an RCBO board?
An RCBO board is not required by regulations but is recommended. With RCBOs, a fault on one circuit does not trip half the house. The extra cost (£100–£200) is worth it for the convenience.
Will the electrician need to turn my power off?
Yes. The power will be off for 4–8 hours during the upgrade. Plan accordingly — charge devices, have a flask of hot water ready, and consider timing the work for a day when you can be flexible.
Need an electrician?
Compare local electricians on Tradehand — coverage areas, accreditations and phone numbers, no middleman.
Find an electrician