A bulb that flickers occasionally is usually just dying. Lights that flicker in one specific room — particularly when something else turns on, or when it's windy outside — are telling you something more important about your wiring. Here's how to figure out what.
Test 1: Does It Flicker With New Bulbs?
Swap one of the flickering bulbs for a new LED. If the flicker stops, you had a dying bulb (or a wrong-spec bulb on a dimmer circuit — see test 4). If it still flickers, there's a circuit issue.
Test 2: Does It Flicker When Big Appliances Run?
Watch the lights when the kettle, washing machine or shower comes on. A brief dim is normal. A persistent flicker that follows the appliance is a loose connection somewhere — most often at the consumer unit, in a junction box, or at the meter tails.
This is a real safety issue (loose connections cause arcing and overheating) and not a DIY fix. Don't leave this — call an electrician within a few days.
Test 3: Does It Flicker in Wind / Wet Weather?
Lights flickering during storms usually mean a connection issue at the meter or in the supply itself. The grid voltage fluctuates slightly and a loose connection makes it visible.
Step 1 is reporting it to your DNO (distribution network operator) — for most of the area I cover that's UK Power Networks. They check the supply and meter free of charge. If the supply is fine, the issue is internal.
Test 4: Is It a Dimmer Switch with LEDs?
Most older dimmer switches were made for halogen and incandescent bulbs. LEDs need a "trailing edge" or "LED-compatible" dimmer. The wrong combination causes random flickering, buzzing, or LEDs that don't turn fully off.
Easy fix: replace the dimmer with an LED-compatible one (£15-£25). Also check the LEDs are dimmable — not all are, and a non-dimmable LED on a dimmer will flicker no matter what dimmer you use.
Test 5: Old Wiring or Loose Junctions?
In houses built before the 1970s with original wiring, age alone causes connections to loosen. Lath-and-plaster walls also let loose connections shift over decades.
I find these by isolating the affected circuit, opening the relevant junction boxes, and checking each connection with a torque screwdriver to manufacturer spec. Usually 1-2 hours' work and £80-£150 to fix permanently.
When to Call an Electrician
If new bulbs and a new dimmer don't solve it, you need someone with proper test equipment. I cover Pinner, Hemel Hempstead, Harrow, Watford, Northwood and the surrounding area for fault-finding visits — typically £110 + materials, often resolved in the first hour. Call 07405 629 940.