Most flickering we are called out to falls into three buckets: an incompatible dimmer, a loose connection, or something happening upstream of your house. The first is an annoyance, the second is a fire risk worth treating seriously, and the third is a job for your network operator rather than an electrician.
Dimmer and LED mismatch
Retrofit LED lamps draw very little current, and older trailing-edge dimmers were designed for filament loads. The result is flicker at low brightness, or lamps that glow faintly when switched off. Changing to a dimmer rated for LED loads, and checking the minimum load figure, resolves most of these.
Loose terminations
A connection that is not fully tight heats up, expands, and makes intermittent contact. That shows as flicker that comes and goes with load or temperature. It is also how junction boxes scorch. If flicker affects several fittings on one circuit, or coincides with a heavy appliance switching on, we would want to check terminations at the switch, rose and board.
Whole-house dimming
If every light in the property dips at once — especially when a neighbour's equipment starts, or during bad weather — the cause may be on the supply side. We can test the incoming voltage and earth loop impedance and, if the readings point upstream, tell you exactly what to report to the network operator.
Common questions
- Is flickering dangerous?
- It can be. Flicker caused by a loose or heating connection is a genuine fire risk, which is why we do not recommend living with it.
- Why do only my kitchen downlights flicker?
- Usually a driver or dimmer issue confined to that circuit, or a transformer nearing the end of its life.
- Will new bulbs fix it?
- Sometimes, if the lamps are the wrong type for the control gear. If new lamps flicker too, the wiring or dimmer is the problem.
- Can you test without pulling the ceiling apart?
- Yes. Most diagnosis is done at the accessories and the board, and we only open up ceilings when the readings say we must.
Tell us which rooms flicker and whether it happens with a specific appliance — that alone narrows the fault considerably.
Related guides
- Why Your Fuse Box Keeps TrippingA consumer unit that trips is doing its job — the question is what it keeps objecting to.
- Getting LED Dimming RightMost LED dimming complaints are a compatibility problem, not a faulty lamp.
- LED Downlights, Spotlights and Retrofit LampsThe right choice depends on whether you are replacing lamps or replacing a ceiling's worth of old transformers.