Flickering LEDs are one of the most common lighting complaints in UK homes and hotels — and in most cases the cause is one of five things. Work through this checklist from cheapest fix to most involved.
Quick diagnosis flowchart
1. Incompatible dimmer (the most common cause)
Old leading-edge dimmers were designed for 40–400W of incandescent load. A handful of 5W LEDs sits below their minimum load, causing flicker, buzzing or lights that won't turn fully off. The fix is a trailing-edge LED dimmer with a low minimum load — see our LED dimmer guide and dimmer range. Check your bulbs are marked dimmable, too: non-dimmable LEDs on any dimmer will flicker and fail early.
2. Cheap or failing LED drivers
Every LED needs a driver to convert mains AC. Budget bulbs and strip-light PSUs with undersized capacitors produce visible ripple flicker, which worsens as they age. Swapping to quality lamps — such as Luceco LED bulbs — usually cures it.
3. Loose connections
Flicker isolated to one fitting, or triggered by vibration (footsteps upstairs), points to a loose terminal at the switch, rose or lamp holder. Isolate the circuit, prove dead, and check terminals are tight. If flicker affects whole rooms and lights dip when appliances start, that suggests a loose neutral or supply issue — stop and call a qualified electrician; a loose main neutral is dangerous.
4. Voltage fluctuation from big loads
Momentary dimming when an oven, shower or vacuum starts is voltage drop. Occasional dips are normal; constant dipping justifies an electrician's investigation of the circuit design.
5. Smart switches and minimum loads
Some smart/WiFi switches leak a small current through the lamp to power themselves, making low-wattage LEDs shimmer when "off". Use switches rated for no-neutral LED loads, or fit a bypass capacitor.
Refurbishing a hotel or HMO? Flicker-free corridors and emergency lighting compliance go together — see the emergency lighting guide (BS 5266) and our lighting range.
FAQs
Why do my LEDs flicker on a dimmer?
Usually a leading-edge dimmer whose minimum load exceeds the small LED load, or non-dimmable lamps. Fit a trailing-edge LED-compatible dimmer and dimmable lamps.
Why do my LEDs glow when switched off?
A small leakage current — often from smart switches or illuminated rockers — charges the LED driver. A bypass capacitor across the fitting, or a switch designed for LED loads, stops it.
Is flickering dangerous?
Lamp-level flicker is an annoyance, not a hazard. Property-wide flickering or dimming, warm plates, or buzzing at the consumer unit can indicate loose connections and needs a qualified electrician promptly.