Low-Voltage Systems · Buried Cables · Timers & Sensors · Kettering

Garden Lighting Faults Diagnosed Without Guesswork

When garden lights stop working, the fault can be in the supply, transformer, driver, timer, sensor, external cable, buried joint or individual fitting. We diagnose garden lighting systems properly before deciding whether repair or replacement makes sense.

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Cable & Driver Faults
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Not Sure If Garden Lighting Is Safe?

If the lights trip, flicker, fail after rain or have visible cable damage, start with safe triage before opening any external joint, fitting or transformer enclosure.

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System Faults

Garden Lights Not Working? The Fault May Not Be the Light Itself

Garden lighting systems often include several parts before power reaches the fitting: a supply circuit, timer, photocell, PIR or sensor, transformer or LED driver, external cable, buried or weatherproof joints, and then the light fittings. One failed component can take out the whole system, while one bad joint can leave only part of the garden dark.

This page is specifically about garden lighting systems and multiple-light faults. For general exterior lights such as security lights, PIR floodlights, wall lights and driveway lights, see our outdoor lighting repairs page.

Low-voltage garden lighting is common, but low voltage does not mean the system can be ignored. The transformer or driver is usually supplied by mains electricity, and outdoor joints, cables and fittings still need to be suitable for the environment.

Wall-mounted outdoor security floodlight
Supply Side
Consumer unit protection, switches, timers, photocells and the circuit feeding the garden lighting equipment.
Transformer Side
Low-voltage transformers, LED drivers, loading, output voltage and weather exposure around control gear.
Cable Side
External cable routes, buried sections, branch points, connectors and joints damaged by water or landscaping.
Fitting Side
Failed lamps, LED fittings, corroded terminals, cracked housings and water ingress inside individual lights.
Low Voltage vs Mains

Low-Voltage Garden Lighting and Mains Garden Lighting

Low-voltage garden lighting usually uses a transformer or driver to reduce voltage before feeding the garden fittings. It is popular for spike lights, path lights and feature lighting because the fittings can be smaller and the design more flexible. The mains side of the transformer still needs to be safe, protected and installed correctly.

Mains-powered garden lighting runs at 230V and may feed bollards, wall lights, larger feature lights or fixed external lighting circuits. These systems need suitable cable, protection, weatherproof accessories and testing. If they trip an RCD or behave differently in wet weather, the circuit should not be repeatedly reset.

Low Voltage Is Not a Free Pass

A low-voltage fitting may be safer than mains at the light head, but the system still contains mains equipment, outdoor joints, drivers, transformers and cables that can fail. If you are unsure, stop using the system and ask a qualified electrician.

Whole System vs One Area

All Lights Off, or Only Some?

If the whole garden lighting system is dead, the fault is often upstream: a timer, photocell, transformer, driver, supply circuit or RCD. If some lights work and others do not, the fault is more likely after a branch point: a corroded connector, damaged cable section, failed lamp, failed fitting or one overloaded driver output.

That difference changes the diagnostic route. Replacing one garden light will not fix a failed transformer, and replacing a transformer will not repair a waterlogged joint buried along the cable route.

Common Causes

Why Garden Lighting Systems Fail

Transformer or driver failureDrivers can fail through age, heat, water exposure, overload or unsuitable enclosure positioning.
Timer, photocell or sensor faultsControls can fail, lose settings, stick on, stay off, or behave unpredictably after water ingress.
Damaged buried or external cableDigging, landscaping, edging tools, movement, settlement and animal damage can break insulation or conductors.
Water ingress in joints or fittingsOutdoor connectors, glands and fittings fail when seals crack, cable entries are poor or joints are not suitable for external use.
Failed lamps or LED fittingsIndividual light heads can fail while the rest of the system remains healthy, especially on older LED garden lights.
RCD tripping from moisture or cable damageEarth leakage from wet joints, damaged cable or failed fittings can trip the RCD, sometimes only after rain.
External Cables

Buried and External Garden Lighting Cable Faults

Garden lighting cable has a harder life than most indoor wiring. It can be clipped along fences, run through beds, buried under paths, routed around patios or joined near planting. The cable type must suit the installation, and any joints need to be suitable for outdoor or buried use.

A cable fault can sometimes be repaired, but not always. If there is one clean damage point and the route is otherwise sound, a suitable weatherproof or buried joint may be possible. If the cable has several poor joints, wrong cable type, repeated water ingress or a vulnerable route, replacing a section may be more reliable.

Route Matters

Garden lighting routes should reduce damage risk from spades, edging tools, pets, vehicles, foot traffic and future landscaping. A hidden cable that no one knows about is easy to damage later.

What We Check

How We Diagnose Garden Lighting Faults

01
Protective Device Behaviour
We check whether an RCD, RCBO or breaker is tripping and whether the fault appears when the garden lighting is switched on.
02
Supply and Controls
Timers, photocells, sensors, switches and supply-side connections are checked before assuming the garden cable or fittings are faulty.
03
Transformer or Driver Output
For low-voltage systems, we check whether the transformer or LED driver has correct output and whether it is overloaded or damaged.
04
Cable and Joint Testing
Where appropriate, insulation resistance and continuity testing helps separate cable-side faults from fitting-side faults.
05
Repair or Replacement Options
We explain whether a joint, fitting, driver, cable section or full system upgrade is the sensible route.
Safe Immediate Steps
  1. 1
    Turn off the affected circuit if garden lights are tripping, wet, visibly damaged, overheating or failing intermittently.
  2. 2
    Do not keep resetting an RCD that trips when garden lighting is used. Repeated resets do not dry out waterlogged joints or repair damaged cable.
  3. 3
    Do not dig around suspected cables while energised. Switch off first and avoid disturbing the route until it has been assessed.
  4. 4
    Avoid opening external joints in wet conditions unless you are competent, the circuit is isolated, and it has been proved dead.
  5. 5
    Call a qualified electrician if the fault involves water, buried cable, RCD tripping, control gear or fixed wiring.
When to Call

When Garden Lighting Faults Need an Electrician

Call a qualified electrician if the system trips the RCD, only fails after rain, has damaged external cable, has wet or corroded joints, or includes mains-fed control gear. Garden lighting faults often need proper testing because the visible failed light is not always the source of the problem.

Attendance depends on workload, urgency, access and location. If the garden lighting circuit can be isolated and the area made safe, we can usually plan the next step. If there is burning smell, exposed cable, water in equipment or repeated tripping, contact us for advice before using it again.

Related
Outdoor Lighting Repairs
Security, wall and PIR lights →
External Power
Outside Socket Installation
RCD and outdoor cable design →
Hub
Electrical Faults & Fixes
Common home faults →
Related Fault
RCD Keeps Tripping
Moisture and leakage faults →
Urgent
Emergency Electrician
Damaged or wet electrics →
Contact
Ask Entigen
Send details and photos →
Repair or Replace

When Garden Lighting Can Be Repaired

Repair May Be Sensible
  • One accessible cable damage point can be joined using a suitable outdoor or buried joint.
  • A timer, photocell, transformer or driver has failed but the cable route tests correctly.
  • One fitting, lamp or connector has failed while the rest of the system remains sound.
  • The installation uses suitable cable and the fault is localised.
  • The load is within the transformer or driver rating.
Replacement May Be Better
  • There are multiple poor joints, waterlogged connections or repeated failures.
  • The cable type is not suitable for the route or environment.
  • The transformer or driver is overloaded for the number of fittings.
  • Buried routes are unknown, vulnerable or repeatedly damaged by landscaping.
  • Several LED fittings have failed and matching parts are no longer available.
Common Questions

Garden Lighting Fault FAQs

A whole garden lighting system failure often points to the supply, timer, photocell, transformer, driver or a common cable fault before the lights split into separate runs. If the RCD has tripped, moisture or cable damage may be involved. A qualified electrician can test whether the fault is supply-side, transformer-side, cable-side or fitting-side.
Garden lighting cable can sometimes be repaired if the damaged section is accessible and a suitable outdoor or buried joint can be made. In other cases, replacement is better, especially where the cable type is unsuitable, several joints have failed, insulation is degraded, or the route is vulnerable to future damage from digging, landscaping or foot traffic.
Low-voltage garden lights are not automatically risk-free. The transformer or driver is still supplied by mains electricity, and outdoor cables, joints and fittings can still fail, overload or allow water ingress. If lights are tripping, damaged, wet, intermittent or connected to fixed wiring, use a qualified electrician.
Garden lights commonly trip because water has entered a fitting, joint, transformer enclosure or cable connection, or because a buried or external cable has been damaged. Other causes include overloaded drivers, failed LED fittings, corroded connectors and faults that only appear after rain or when the ground is wet.
If some garden lights work and others do not, the fault may be after a branch point in the cable, at a connector, inside one fitting, or on one transformer output. It may also be caused by voltage drop, a failed lamp, corroded joint or a damaged cable section serving only part of the garden lighting system.
Fault Support

If your issue sounds similar, these pages may help you understand the fault before getting in touch.

Outdoor Lighting Repairs Outside Socket Installation RCD Keeps Tripping Electrical Faults & Fixes Contact Entigen

Garden Lighting Fault in Kettering?

Tell us whether the whole system is off, only some lights have failed, whether the RCD trips, and whether rain or recent garden work changed anything. We will confirm the practical next step before attending.

Phone
01536 645661
Mobile
07950 512246
Email
sales@entigen.co.uk
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Mon–Fri 8:30–16:30 · NAPIT Registered · Serving Kettering and Northamptonshire