All categories

Lighting

Lights out, flickering, downlights, dimmers and LEDs.

Lighting

A single light not working

One light fitting is dead while the rest of the lights on the circuit work fine — points at the lamp, the fitting, or the switch for that point rather than the whole circuit.

4 causes3 test steps
ApprenticeMedium risk
Lighting

Lights flickering

One or more lights flicker — constantly, intermittently, or when other appliances run. Common with LEDs and dimmers, but can also signal a loose connection.

5 causes3 test steps
QualifiedMedium risk
Lighting

Downlights cutting out then coming back

Downlights switch off after a while then come back once cooled — classic thermal cut-out behaviour, usually from heat build-up around the fitting or driver.

4 causes3 test steps
QualifiedMedium risk
Lighting

Dimmer buzzing or LEDs not dimming smoothly

A dimmer buzzes, the LEDs flicker/strobe at low levels, won't go very low, or some lamps glow when 'off' — typically an LED/dimmer compatibility issue.

4 causes2 test steps
ApprenticeLow risk
Lighting

Fluorescent light not starting or flickering

A fluorescent tube won't strike, flickers, or glows only at the ends — common in older garages, laundries, and sheds.

4 causes3 test steps
ApprenticeMedium risk
Lighting

All lights in one area out (others fine)

Every light in one part of the house is dead while power points and other lighting still work — points at that lighting circuit's protective device or a shared fault.

4 causes3 test steps
ApprenticeMedium risk
Lighting

LED lights glowing faintly when switched off

LED lamps glow dimly or pulse even after the switch is off — unsettling but usually a small leakage/induced-voltage effect rather than a dangerous fault.

4 causes2 test steps
QualifiedLow risk
Lighting

Motion-sensor light not working correctly

A sensor (PIR) light won't come on, stays on permanently, or triggers at the wrong times — common on eaves, garages, and entries.

4 causes3 test steps
ApprenticeLow risk
Lighting

Two-way light switch — works from one switch but not the other

A stair, hallway or bedroom light on two-way switching only behaves from one position — the other switch does nothing, or the light only works with the switches in certain combinations. Classic after a switch has been replaced.

4 causes4 test steps
ApprenticeMedium risk
Lighting

Light bulbs keep blowing in the same fitting

One fitting eats lamps — sometimes weekly — while the rest of the house is fine. The lamp isn't the problem; something about that fitting or its supply is.

5 causes4 test steps
ApprenticeMedium risk
Lighting

LED batten / panel flickering or strobing

An LED batten or panel (garage, office, retail) flickers, strobes, or won't switch off cleanly — common with cheaper fittings, sensors, or shared neutrals.

4 causes2 test steps
QualifiedMedium risk
Lighting

High-bay or floodlight not working / cutting out

A high-bay (warehouse) or floodlight is out or cuts out after warming up — pointing at the driver, heat, supply, or a daylight/photocell control.

4 causes2 test steps
QualifiedMedium risk
Lighting

Lighting circuit trips its breaker

The breaker (or RCBO) feeding a lighting circuit trips — either the moment it's switched on, or after the lights have been on a while. Resetting holds for a bit or trips straight back.

5 causes3 test steps
QualifiedMedium risk
Lighting

Light switch warm, buzzing or crackling

A switch plate feels warm to touch, buzzes, or crackles when operated. Lights may flicker as you toggle it, and there can be a faint hot-plastic smell.

4 causes3 test steps
ApprenticeHigh risk