What temperature should my consumer unit be and when is it dangerous – Advice from Electriman, North London Electricians

Is My Consumer Unit Too Hot?

Your consumer unit (also called a fuse box) should feel slightly warm at most — never hot. A small amount of warmth is normal because electrical components generate a little heat during operation, but anything beyond that warrants attention.

What is a normal temperature?

In a room at around 20–25°C, the consumer unit surface should stay below 35°C — barely warm to a careful touch

The internal components (busbars, breakers) should be no more than 10°C above ambient under normal load

Anything you cannot comfortably hold your hand near for several seconds is too hot

Warning signs you should never ignore:

Hot to the touch on the casing or cover

Burning smell — plastic, rubber, or a sharp electrical odour

Discolouration or scorch marks around breakers or cables

Breakers tripping repeatedly without an obvious cause

Buzzing or crackling sounds from inside the unit

Flickering lights throughout the property

What you can safely check yourself:

Stand back and look for any visible scorch marks or melting plastic on the outside

Sniff carefully near (not touching) the unit for burning smells

Check whether any breakers or RCDs have tripped — reset only if it is safe and you know why they tripped

Check that the area around the unit is clear — units must not be enclosed in tight spaces that trap heat

What you must NOT do:

Do not ope

Need a qualified electrician in North London?

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