Things you can check
- One bulb flickering: switch off, let it cool, and check it's screwed or pushed in properly. Try a new bulb.
- LED bulbs on a dimmer: not all LEDs are dimmable, and not all dimmers suit LEDs. A mismatch is a very common cause of flicker or buzzing.
- Flicker when a big appliance switches on (a washing machine or heater): a brief dip can be normal, but frequent or severe dimming is worth getting checked.
Signs it could be a wiring problem
- Flickering in several rooms, or the whole house
- Buzzing or crackling from switches or light fittings
- Warm or discoloured switches or ceiling roses
- Flickering along with a burning smell
Safety first
Always switch off and let a bulb cool before touching it. If you notice heat, buzzing or a burning smell from a switch or fitting, switch that circuit off at the consumer unit and get it checked. See burning smell: what to do.
If lights across your street are flickering too, the problem may be on the network: report it to your network operator on 105.
When to call an electrician
- Flickering on more than one circuit or room
- Any buzzing, heat or smell
- It continues after changing the bulb and checking dimmer compatibility
Sources and further reading
- Electrical Safety First – Lighting
- Electrical Safety First – Fire prevention tips
- Electrical Safety First
General guidance only, based on the sources above. Last reviewed October 2026. It isn't a substitute for an inspection by a qualified electrician.