What is this?
When lights stop working but sockets remain powered, the lighting circuit has a fault while socket circuits are unaffected. UK homes typically have one or two dedicated lighting circuits separate from socket circuits.
Common causes
- MCB for the lighting circuit has tripped
- Faulty light fitting causing the circuit to trip
- Loose connection at a ceiling rose or junction box
- Failed LED driver in a light fitting
- Damaged cable in the loft or ceiling void
Is it dangerous?
Not an emergency, but you should not ignore it. A tripped lighting circuit MCB indicates a fault that needs diagnosis. Working in the dark can itself be a safety risk, so use torches and be careful on stairs.
Can I fix it myself?
Check the consumer unit for a tripped lighting MCB and try resetting it. If it trips immediately, switch off all light switches and try again. Then turn lights on one at a time to identify which one causes the trip. Check that bulbs are not loose or the wrong type for the fitting.
When to call an electrician
Call an electrician if the MCB trips with all switches off, if you cannot identify the faulty light, or if the problem started after any DIY work. Lighting circuit work should always be done by a qualified person.
What will an electrician do?
Test the lighting circuit for faults
Check each light fitting, switch, and junction box on the circuit
Inspect wiring in the loft and ceiling voids
Replace faulty fittings, switches, or connections
Test the circuit after repair to confirm it is safe
Typical cost
£80 – £200
Most lighting faults are resolved with a simple repair. Costs increase if access to hidden wiring is needed.
