Why won't my consumer unit main breaker reset – Advice from Electriman, North London Electricians

Why Won't My Consumer Unit Main Breaker Reset?

The main switch (sometimes called the main breaker or incomer) in your consumer unit is a safety device. When it trips or refuses to reset, it means something on your electrical installation has caused it to operate — and it is protecting you from a potentially dangerous situation.

What the Main Switch Actually Does

The main switch isolates your entire home's electrical supply from the meter tails. It is not a standard MCB (miniature circuit breaker) — it is usually a 100A double-pole isolator or a combined RCD/RCBO main switch. If it has tripped rather than simply been switched off, there is an underlying fault.

Safe Steps You Can Try Yourself

Switch off every individual circuit breaker inside the consumer unit before attempting to reset the main switch. This removes any downstream load.

Try to reset the main switch — if it now holds, switch circuits back on one at a time until you find the faulty one.

Check for obvious causes — a recently plugged-in appliance, a trip caused by a power cut, or accidental knock.

Look for signs of burning or smell around the consumer unit — if present, do not touch anything and call an electrician immediately.

Check your electricity meter — if the meter shows no supply, the fault may be with your DNO (Distribution Network Operator) rather than your consumer unit.

When You Must Call a Qu

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Electriman covers Mill Hill, Barnet, Finchley, Edgware, Enfield, Watford and surrounding areas. All work is Part P certified and fully insured.