Do I need a new fuse board?
Probably not just because it is old. A fuse board needs replacing when an inspection finds it is no longer protecting you properly, or when you are adding load it cannot carry. Here is how to tell which side of that line yours is on.
Age is not the trigger. Findings are.
There is no rule in BS 7671, the wiring regulations, that says a fuse board expires at fifteen or twenty years. Some websites say there is. There is not. A board with rewirable fuses that was properly installed and has never been overloaded is not automatically dangerous, and no inspector will fail it on age.
What an inspector will do is test the installation behind it. That is an Electrical Installation Condition Report, and its findings are the real answer to this question. The board is replaced when the report says the protection is missing or not working, not when a calendar says so.
The four honest reasons to replace one.
- No RCD protection where you need it. An RCD cuts the power in a fraction of a second when current leaks to earth, which is what stops a damaged cable or a wet garden socket becoming a shock. Older boards often have none. Missing RCD protection on circuits feeding a bathroom, or sockets that could run equipment outdoors, is the finding that most often turns a report unsatisfactory.
- Adding load it cannot carry. An EV charger, an electric shower, a heat pump, a kitchen extension. Each wants its own circuit and its own protection, and an old board with no spare ways has nowhere to put them. Replacing the board is the enabling job for the thing you actually want.
- Nuisance tripping that traces back to the board. A single RCD protecting the whole house means one faulty kettle blacks out everything. If yours trips often and the fault keeps moving, splitting circuits across separate protection is usually the fix.
- Physical condition. Heat marks, a cracked enclosure, loose or scorched terminals, a lid that does not close. These are C1 or C2 findings in their own right and the board goes.
When you can leave it alone.
If a recent report is satisfactory, the house has RCD protection where it matters, you are not adding load, and the board is in sound condition, you do not need a new one. Plastic enclosures are a good example of something that gets sold as urgent. Since 2016 new domestic consumer units have had to be in a non-combustible enclosure, which in practice means metal. That rule applies to new boards. It does not make an existing plastic board a fail, and an inspector will usually record it as an observation rather than a defect.
What the price is made of.
We do not publish figures because the same job varies from house to house, and we would rather explain why than guess. The price is built from the number of circuits, the type of protection each one needs, the condition of the main earthing and bonding to the gas and water pipes (which must be right before a new board can be certified, and often is not in older houses), whether the meter tails need replacing, the testing of every circuit afterwards, and the certificate and Building Regulations notification. The board itself is a small part of it.
What happens on the day.
Replacing a consumer unit is notifiable work under Part P of the Building Regulations in England, so it must be done by a registered electrician who certifies and notifies it. Expect the power to be off for a good part of the day. Every circuit is tested before it is reconnected, which is the part that takes the time and the part that matters. You get an Electrical Installation Certificate, the notification is done for you, and you should keep both with the house paperwork. If you let a property, the Electrical Safety Standards in the Private Rented Sector Regulations mean a satisfactory report every five years, so the certificate for a new board is worth keeping to hand for your next one.
We fit boards across all four counties. If you are in Hemel Hempstead or Aylesbury we are there most weeks anyway.
Sources: BS 7671, the IET Wiring Regulations; Approved Document P, Electrical safety; The Electrical Safety Standards in the Private Rented Sector (England) Regulations 2020.
Asked about this.
How do I know if my fuse box needs replacing?
Have it inspected. An EICR tests the installation and tells you in coded findings whether the protection is adequate. Missing RCD protection, no spare ways for a circuit you need, a board that trips constantly, or visible damage are the real reasons. Age on its own is not one.
How long should a fuse board last?
There is no fixed lifespan in the regulations. A well installed board in a dry location can serve for decades. What changes is what the regulations expect of new work, so an older board usually gets replaced when the house needs something it cannot provide, not because it has worn out.
Are old fuse boxes still legal?
Yes. The wiring regulations are not retrospective, so an installation that met the rules when it was fitted is not illegal now. If you let the property, the installation must pass an inspection every five years, and an old board can fail that on its findings, but not on its age.
Can you get a new fuse box without rewiring?
Usually, yes. The board and the wiring are separate jobs. The existing circuits are tested before the new board goes on, and if they are sound they stay. If testing finds a circuit that cannot be made safe, you are told before the work starts, not after.