Why is my electrical panel showing signs of burning plastic smell when it's cold – Advice from Electriman, North London Electricians

A burning plastic smell coming from your consumer unit or fuse box is never normal and should always be taken seriously. In cold weather this can become more noticeable because metal components contract slightly in lower temperatures, which can worsen connections that were already loose or corroded. Here is what you need to understand and what you can safely do.

What is likely causing it

The most common cause is a loose or corroded connection inside the panel. When electrical current passes through a poor connection, it generates heat rather than flowing cleanly. This heat can melt the plastic insulation on wires or the plastic casing of circuit breakers. Other possible causes include an overloaded circuit, a failing circuit breaker that is not tripping when it should, rodent damage to wiring inside the panel, or an ageing consumer unit that has reached the end of its serviceable life.

Why cold weather makes it worse

Metals expand in heat and contract in cold. If a connection inside your panel was already slightly loose, a drop in temperature can cause the metal to pull away just enough to increase resistance further. This creates more heat during normal use, which is why the smell may be more noticeable on cold mornings when the heating kicks in and demand on your circuits rises.

What you can safely check yourself

1. Stand back and look at the outside of the panel for any scorch marks, discolouration, or melting around

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.