RCBO consumer unit: is it worth it?
By Azzeddine Kebbi, NAPIT-registered electrician and director of Kebbi Electrical Services · Updated 10 November 2026
An RCBO consumer unit gives every circuit its own combined RCD and circuit breaker. If one circuit has a fault, only that circuit switches off, instead of half the house. It costs more than a dual RCD board, but for most homes it is the better choice.
RCBO board vs dual RCD board
RCBO consumer unit
Each circuit has its own RCBO. A fault trips only that circuit, so the lights and fridge stay on.
Dual RCD (split-load) board
Two RCDs each protect a group of circuits. One fault can switch off every circuit in that group.
Why people choose RCBOs
- Fewer nuisance trips taking out several circuits at once.
- Faults are easier to find, because you can see which circuit tripped.
- Small leakages from several circuits do not add up on one shared RCD.
- Useful for freezers, alarms and home offices that should stay on.
Things to know
- An RCBO board usually costs more than a dual RCD board because each RCBO costs more.
- New consumer units in homes must have a non-combustible (usually metal) enclosure.
- Replacing a consumer unit is notifiable work. Use a registered electrician who tests every circuit and issues the certificates.
Common questions
What is the difference between an RCD and an RCBO?
An RCD protects against earth leakage only. An RCBO combines an RCD with a circuit breaker (MCB), so it also protects one circuit against overload and short circuit.
Is an RCBO consumer unit worth it?
For most homes, yes. One fault only switches off one circuit, which makes faults easier to find and avoids losing half the house.
Can I add RCBOs to my existing consumer unit?
Sometimes, if the board is compatible and in good condition. Many older boards are not, so an electrician needs to check.
Does a new consumer unit need certifying?
Yes. Replacing a consumer unit is notifiable under Part P. A registered electrician issues an Electrical Installation Certificate and notifies building control. See what is a Part P certificate.
Thinking about an upgrade?
We install and certify consumer units across Bristol. See our consumer unit upgrades.