What is this?
Garden lighting includes a wide range of installations from low-voltage LED path lights to mains-voltage bollard lights and wall-mounted fittings. When they stop working, the cause is usually a failed transformer, a damaged cable, or a faulty fitting. Low-voltage garden lights (12V) are less dangerous than mains-voltage outdoor lights.
Common causes
- Failed transformer or driver unit for low-voltage LED garden lights
- Damaged cable from gardening activity (digging, mowing, strimming)
- Corroded connections at junction boxes or light fittings
- Tripped MCB or RCD on the outdoor lighting circuit
- Timer or photocell sensor not set correctly or has failed
Is it dangerous?
Low-voltage garden lights (12V) pose minimal shock risk, but mains-voltage outdoor lights (230V) are dangerous if cables are damaged. If you suspect a mains cable has been cut by a spade or mower, do not touch it. Turn off the circuit at the consumer unit immediately.
Can I fix it myself?
For low-voltage LED garden lighting, check the transformer is plugged in and working, and inspect visible cable connections for damage or corrosion. Replace any blown bulbs. For mains-voltage lighting, only check the consumer unit for tripped MCBs. Do not attempt to repair mains-voltage outdoor wiring yourself.
When to call an electrician
Call an electrician if you have mains-voltage garden lights that are not working, if you have accidentally cut through a cable while gardening, if the outdoor circuit keeps tripping, or if you want to install new permanent outdoor lighting. Any new mains-voltage outdoor circuit requires Part P notification.
What will an electrician do?
Trace the outdoor lighting circuit and test for cable damage or breaks
Inspect and clean corroded junction boxes and connections
Replace failed transformers, drivers, or light fittings
Repair or replace damaged buried cables with correctly rated armoured cable (SWA)
Test the completed circuit and issue appropriate certification
Typical cost
£80 – £200
Fault-finding and repair on existing garden lighting. New outdoor lighting installations with buried armoured cable start from around £400.



