Lights Flickering? Causes, Safe Checks and When to Call an Electrician

By Tim, NICEIC registered electrician · Published 6 October 2026 · 6 min read

Lights that flicker are usually down to the bulb, the dimmer or a loose connection. One light flickering on its own is normally the bulb, or an LED that doesn’t suit the dimmer switch. Lights that flicker when the kettle or the shower comes on are often just a heavy load starting up. Flickering with a buzz, a burning smell, a warm switch or scorch marks means a loose connection that’s arcing, and that wants an electrician straight away. If every light in the house flickers, check whether the neighbours have it too.

In Poole or Bournemouth, ring Tim on 07809 680068. Planned fault finding starts from £85.

Burning smell or a hot switch? Switch that circuit off at the fuse box, or the main switch if you’re not sure which one, and call us. Emergency call-outs start at £150 including the first hour.

Lights flickering: work out which kind you have

Safe checks you can do yourself

1. Change the bulb. Switch off first and let it cool. If a new bulb fixes it, that was the problem.
2. Check the bulb is tight. A bayonet or screw bulb that isn’t seated properly will flicker when there’s any vibration.
3. Check the dimmer. If the flicker started when you changed to LEDs, the dimmer is the most likely culprit. Older dimmers were made for filament bulbs, and LEDs need a dimmer rated for them. The bulb itself has to say it’s dimmable as well.
4. Watch when it happens. If it lines up with the shower, the oven or the heat pump starting, note it down. That tells an electrician a lot.
5. Ask the neighbours. If they’ve got it too, it’s not your wiring.

Don’t take a light fitting or a switch apart unless you’re qualified, and never with the circuit live.

When flickering lights are dangerous

The flicker itself does no harm. The danger is the cause. A loose connection in a switch, a ceiling rose or a junction box makes a small gap, and the current jumps it. That’s arcing, it gets hot, and it’s one of the ways electrical fires start.

Call an electrician if:

• the switch or the fitting feels warm
• you can hear buzzing or crackling
• you can smell burning or hot plastic
• there are brown or black marks round a switch or fitting
• it keeps happening on one fitting after you’ve changed the bulb
• it’s every light, and the neighbours don’t have it

A loose connection at the main fuse or in the consumer unit can affect the whole house, and on rare occasions it’s a lost neutral, which can put unusual voltages on your circuits. That isn’t something to sit on. Switch off and call us.

Flickering LEDs

LEDs flicker for different reasons from the old filament bulbs. The common ones are:

• The wrong dimmer. It’s the most common cause by a distance.
• Cheap drivers. Every LED has a small driver inside it, and some don’t cope well with small changes in the supply.
• A glow or flicker when they’re switched off. That’s usually a small current getting through an illuminated or smart switch. It isn’t normally dangerous, and changing the switch usually cures it.

If you’re replacing old halogen downlights, it’s worth doing the dimmer at the same time. Our LED downlights start from £65 each, supplied and fitted.

What it costs to fix

Everything we charge is on our prices page. If the fault turns out to be in the fuse box, our fuse box keeps tripping and old fuse box guides explain the next step.

Get it sorted

Lights still flickering? Call Tim on 07809 680068 or send a video on WhatsApp. It often tells us what’s wrong before we arrive. We do everyday electrical work across Poole, Bournemouth, Christchurch and Wimborne, with 24/7 emergency call-outs.

Sources

• Electrical Safety First: warning signs of electrical faults
• SSEN: power cuts, call 105
• Energy Saving Trust: LED lighting

Frequently Asked Questions