What does an RCD do?
A residual current device cuts power within milliseconds if it detects current leaking to earth — the main protection against electric shock from a faulty appliance or damaged cable. Modern consumer units have RCD protection built in across multiple circuits (RCBOs); older ones may only protect part of the property.
How often should wiring be tested?
The IET recommends an electrical inspection every 10 years for an owner-occupied home, 5 years for a rented property, and on change of occupancy for some property types. A periodic inspection is different from routine maintenance — it's a formal check against current wiring regulations, not just a visual look.
Lighting design and circuit planning
Adding recessed downlights, under-cabinet lighting or dimmer circuits usually means new cabling even if you're keeping the existing consumer unit, since older lighting circuits weren't sized for LED transformers or multiple dimmer switches. Plan lighting changes before, not after, a room's redecorated.
Electrical upgrades: EV chargers, solar PV & smart home systems
Beyond repairs, many electricians now fit EV charging points, solar PV inverters and battery storage, and smart home systems — app-controlled lighting, heating and security. These jobs usually need a separate circuit and, for EV chargers, a dedicated consumer unit way — worth checking your existing setup can support the extra load before booking.
Satisfaction and aftercare — support beyond the job
A registered electrician's paperwork doesn't end when the job does — you should receive a Building Regulations compliance certificate (for notifiable work) or an Electrical Installation Certificate, which you'll need if you sell the property or make an insurance claim. Keep this with your household paperwork.
When does a consumer unit need replacing?
Older fuse boxes with rewireable fuses or plastic (rather than metal) casings don't meet current wiring regulations and are a common reason a rewire quote comes in higher than expected. A modern consumer unit uses RCBOs, which cut power to a single faulty circuit rather than the whole property.
Common electrical myths, busted
"If it's not broken, the wiring's fine" — wiring can be dangerous long before it visibly fails. "Any handyman can do electrics if it's small" — scope, not size, determines whether work is notifiable. "A tripped RCD means the RCD is faulty" — usually it means something else on that circuit is, and the RCD is working as intended.
Understanding the labour vs materials split
Materials — consumer units, cabling, sockets, fittings — are usually a smaller share of an electrical quote than labour, particularly for jobs involving lifting floors or chasing walls. If a quote seems unusually cheap, check whether it's using a lower-spec consumer unit or cabling than a competing quote, not just a lower labour rate.