How serious is a burning smell from the fuse box?

Extremely serious. This is an electrical emergency. Turn off the main switch if safe to do so and call an emergency electrician immediately. If there is smoke or flames, call 999.

Should I turn everything off?

Yes, turn off the main switch if you can safely reach it and it is not hot or damaged. This disconnects the load and may slow or stop the overheating. If you cannot safely access it, evacuate.

Do I need a new consumer unit?

If the existing unit has heat damage, the answer is almost certainly yes. Modern consumer units must be metal-clad under BS 7671. If your unit is plastic, this is an additional reason to replace it.

Why do consumer units catch fire?

The most common cause is loose connections. A loose connection creates electrical resistance, which generates heat. Over time, this heat damages the connection further, making it even looser and hotter — a dangerous cycle. This is why periodic inspection (EICR) is important.

How can I prevent this?

Have an EICR carried out regularly (every 10 years for homeowners, every 5 years for landlords). Ensure your consumer unit is modern, metal-clad, and installed by a registered electrician. Do not overload circuits.

Emergency

Updated 30 August 2026

Burning Smell From The Fuse Box

Your consumer unit or fuse box smells of burning — this needs immediate action.

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What's happening?

A burning smell from the consumer unit (fuse box) is extremely serious. The consumer unit is the central distribution point for all your home's electricity, carrying the full load of the property. Overheating here means a connection is failing under the full electrical demand of the house. Consumer unit fires are a significant cause of domestic electrical fires in the UK, which is why BS 7671 now requires all new consumer units to be metal-clad (non-combustible).

What usually causes it?

Loose busbar connections overheating under load
Failing MCB or RCD with degraded internal contacts
Corroded main switch connections
Overloaded consumer unit carrying more current than designed for
Poor workmanship from a previous installation — loose terminals, exposed conductors
Old rewirable fuse carriers with incorrect fuse wire ratings

Is it dangerous?

This is an emergency. The consumer unit carries the highest currents in your home, and a fault here can escalate into a fire rapidly. If you smell burning from the consumer unit, turn off the main switch immediately if it is safe to do so. If the unit is visibly damaged, smoking, or you cannot safely reach it, evacuate and call 999. Do not touch the unit if you can see damage or melting.

Can I fix it myself?

No. If it is safe to do so, turn off the main switch at the consumer unit. If the unit is hot to the touch or smoking, do not touch it — evacuate and call 999 and then an emergency electrician. Do not attempt to open the consumer unit cover under any circumstances.

When should you call an electrician?

Call an emergency electrician immediately. If there is visible smoke, flames, or you cannot safely turn off the main switch, call 999 first, then call the electrician. This is one of the most serious domestic electrical faults.

What will the electrician actually do?

Safely isolate the supply (may need to contact the DNO to pull the main fuse)
Open the consumer unit and inspect all connections for overheating damage
Identify the source of the burning — loose terminal, failing device, or cable issue
Replace any damaged MCBs, RCDs, or the entire consumer unit if compromised
Torque-test all connections to the correct specifications
Issue a Minor Works Certificate or Electrical Installation Certificate as appropriate