Will a new consumer unit fix it, or do you need a rewire?
A new board fixes protection, not wiring. How to tell whether a consumer unit upgrade is enough or your property genuinely needs rewiring.
A new board gives you modern protection: RCDs or RCBOs, surge protection, proper labelling. What it cannot do is improve the cable behind the wall. If the cabling is sound, a board upgrade transforms the installation. If it is not, a new board is lipstick.
The honest test is what a condition report finds on the circuits, not what the board looks like.
- Board upgrade: protection, isolation, compliance with current standards
- Rewire: replaces the cabling, earthing and accessories themselves
- Insulation resistance readings are the deciding evidence
- Fitting a new board to failing cable can expose faults immediately
Why a new board sometimes trips straight away
Old boards with no RCD protection tolerate leakage that a modern board detects instantly. Fit RCDs to tired cabling and circuits start tripping — not because the new board is faulty, but because it is doing its job and revealing what was already there.
We test insulation resistance before quoting so this is a known quantity rather than an unpleasant surprise on the day.
When the board alone is genuinely enough
PVC-cabled installations in reasonable condition with sound earthing gain most of the benefit from a board upgrade at a fraction of a rewire's cost and disruption. That covers a great many properties built or rewired from the 1970s onwards.
When to plan the bigger job
Rubber or fabric cabling, no earth at lighting points, or repeatedly poor insulation readings all point to rewiring. We would rather tell you that up front than take the smaller job and leave you calling someone else next year.
Common questions
Can you test before I commit?
Yes — an EICR gives you the readings and a clear recommendation in writing.
How long does a board change take?
Typically a working day, with power off for part of it.
Will a new board reduce my bills?
No. It improves safety and fault isolation, not consumption.
Get a fixed price
Book an EICR first — it costs a fraction of either job and tells you which one you actually need.