What is this?
When all the lights in your home flicker simultaneously, the problem is with the shared supply rather than an individual circuit. This could be a loose main connection, a fault in the consumer unit, or an issue with the incoming supply from your Distribution Network Operator (DNO). Whole-house flickering should always be taken seriously because it can indicate a dangerous wiring fault.
Common causes
- Loose connection on the main supply tails or meter
- Faulty or deteriorating neutral connection at the cutout or meter
- Problem with the DNO supply — voltage fluctuations or a failing service cable
- Loose busbar connections inside the consumer unit
- Corroded or overheating main switch in the consumer unit
- High-draw equipment on a neighbour's supply affecting the shared neutral (in some older installations)
Is it dangerous?
Yes, whole-house flickering is a serious warning sign. A loose neutral connection can cause dangerous voltage fluctuations — some circuits may receive too much voltage and others too little. This can damage appliances and create a fire risk. If the flickering is accompanied by a burning smell, buzzing from the consumer unit, or appliances behaving strangely (running too fast or too slow), turn off the main switch and call an emergency electrician.
Can I fix it myself?
There is very little you can safely do yourself. Check with your neighbours to see if they are experiencing the same issue — if so, it is likely a DNO supply problem and you should call 105. Do not open the consumer unit or touch the meter or main fuse. If the flickering is severe or getting worse, turn off the main switch and wait for a professional.
When to call an electrician
Call an electrician urgently if all lights in the house are flickering. This is not something to leave. If you smell burning, hear buzzing from the consumer unit, or notice any discolouration or heat around the meter area, treat it as an emergency. If the DNO confirms the supply is fine, an electrician needs to inspect your consumer unit and main connections.
What will an electrician do?
Test the incoming supply voltage for fluctuations or instability
Inspect and tighten all main connections including supply tails and busbar
Check for overheating, arcing, or corrosion at the main switch and connections
Test the neutral integrity throughout the installation
Liaise with the DNO if the fault is on the supply side
Replace the consumer unit or main switch if damaged
Typical cost
£100 – £300
If the fault is on the DNO supply side, their repair is free. Internal connection repairs are at the lower end. A full consumer unit replacement is £350–£600.
