What is this?
In UK homes, lighting and socket circuits are separate. When sockets stop working but lights remain on, it means the socket ring circuit (or radial circuit) has a fault while the lighting circuits are unaffected.
Common causes
- MCB protecting the socket circuit has tripped
- RCD has tripped affecting only socket circuits
- Break in the ring circuit (loose connection or damaged cable)
- Faulty socket causing the circuit to trip
- Overloaded socket circuit
Is it dangerous?
Not immediately dangerous, but a tripped circuit indicates a fault. If the MCB trips repeatedly, there could be a short circuit or earth fault that needs professional attention. Do not bypass the protection by using higher-rated fuses.
Can I fix it myself?
Check your consumer unit for a tripped MCB or RCD. Try resetting it. If it stays on, the problem may have been a temporary overload. If it trips again, unplug everything and try again. If it still trips with nothing plugged in, you need an electrician.
When to call an electrician
Call an electrician if the MCB trips with nothing plugged in, if resetting does not restore power to sockets, or if only some sockets on the circuit are affected (suggesting a break in the ring).
What will an electrician do?
Identify which socket circuits are affected
Test ring circuit continuity (R1, Rn, R2 tests)
Locate any breaks in the ring or loose connections
Test insulation resistance to find earth faults
Repair connections and replace any damaged sockets or cables
Typical cost
£80 – £250
Ring circuit testing and repair is standard work. Costs increase if cables need replacing behind walls.
