Do I need a full rewire, or just a new fuse board?

The short answer

A rewire is a large, disruptive, expensive job. A fuse board replacement is a day’s work. Plenty of people are quoted the first when they only needed the second.

The question is not how old the house is. It is what condition the cable is in.

What actually makes a rewire necessary

The cable is the thing that cannot be upgraded in place. Everything else, the board, the sockets, the switches, can be replaced without pulling up floors.

Cable needs replacing when the insulation has failed or is failing. In practice that means:

• Rubber insulated cable. Common up to the early 1960s. It goes hard, then it cracks, and once it cracks the conductors are exposed inside the wall.
• Fabric or cloth covered cable. Same era, same problem.
• Lead sheathed cable. Older still, and long past its life.
• Brittle PVC. PVC lasts decades, but heat and age eventually take it. If it snaps rather than bends at the board, that is a bad sign.
• No earth on lighting circuits. Very common in houses wired before the mid-1960s. Sometimes fixable circuit by circuit, sometimes not.

If your cable is sound PVC in red and black, or brown and blue, the cable is almost certainly not the problem.

What a new fuse board actually does

A modern consumer unit gives every circuit its own protection, usually an RCBO, which trips on both overload and earth fault. That means a fault on one circuit no longer takes out the whole house, and it means an earth fault disconnects fast enough to protect a person.

It also gives you a board with a proper main switch, correct labelling, and, in most cases, surge protection.

What it does not do is repair cable. That is why an inspection comes before the quote. A new board on top of failing cable is money spent hiding a problem.

How to tell which one you need

Get an EICR. It exists precisely to answer this question.

The report will code what it finds, and the pattern tells you the answer. A handful of C3 items and one or two C2 items on specific circuits means targeted work. C2 items spread across every circuit, with insulation resistance readings dropping low everywhere, means the cable is going and a rewire is the honest answer.

Ask to see the insulation resistance figures. They are the numbers that separate the two cases, and any electrician should be happy to talk you through them.

The honest position

We would rather quote you for a fuse board and some remedials than sell you a rewire you do not need. Partly because it is the right answer, and partly because in a town this size the reputation is the business.

If you want a second opinion on a rewire quote you have been given, call us on 01732 655003. We will tell you what we think, and if the rewire is genuinely needed we will say so.