Flickering Lights — Causes, Fixes & When to Worry
A flickering light isn't always just a duff bulb. Some causes are harmless — others are a fire risk. Here's how a Devon electrician diagnoses the difference.
When to switch off and call us today
Flickering is getting worse over days/weeks; multiple rooms affected at once; a burning smell or warm switch plate; lights dim sharply when an appliance turns on. Any of these = loose connection / voltage drop = fire risk.
The 6 most common causes
- LED bulb + leading-edge dimmer mismatch (the #1 cause we see)
- Loose neutral in the consumer unit, junction box or back of a switch
- Failing CFL/LED driver inside the lamp itself
- Voltage drop from undersized cable or service-head fault
- Appliance on a shared circuit (kettle, shower, oven) drawing peak current
- Network supply issue from the DNO (we can confirm and report it)
Lights flickering? We'll find it fast
From £85 plus VAT for diagnosis. CHAS approved. Devon-wide.
Frequently Asked Questions
Why are my lights flickering?
The most common causes are: an incompatible LED + dimmer combination, a loose neutral connection in the consumer unit or a junction box, a failing light fitting, voltage fluctuation from the supply, or a large appliance (kettle, shower) drawing current on a shared circuit. Loose neutrals are the dangerous one and need investigation immediately.
Are flickering lights dangerous?
They can be. A loose neutral connection causes flickering and is also a fire risk — connections heat up and arc. If flickering is widespread, getting worse, or accompanied by a burning smell, switch off at the consumer unit and call us today.
Why do my LEDs flicker but old bulbs didn't?
LEDs draw very little current and react instantly to tiny voltage changes that an old filament bulb would simply absorb. Often the fix is a "trailing edge" LED-compatible dimmer switch, or replacing the LEDs with a brand designed for dimming.
Lights flicker when the kettle / shower is on — why?
This indicates voltage drop, usually from undersized cable or a loose connection at the consumer unit, meter tails or service head. We can measure the voltage drop and identify the cause in one visit.
How much does it cost to fix flickering lights?
Most flickering light call-outs in Devon are £85 plus VAT for the first hour. Many faults (loose terminal, wrong dimmer) are fixed within that hour. Insulation testing or part-replacement is quoted before any extra work.