Why does my RCD trip when it rains – Advice from Electriman, North London Electricians

Why Your RCD Trips in the Rain

An RCD (Residual Current Device) is a safety device that trips when it detects electricity leaking to earth — for example through water, a damaged cable, or a faulty appliance. Rain can trigger this because water is a conductor and can find its way into places it shouldn't be.

Most common causes:

Outdoor sockets or garden power outlets — even IP-rated (weatherproof) sockets can allow water ingress if seals degrade or covers are left open

External lights or flood lights — if the fitting isn't rated for outdoor use or the seal has failed, rainwater gets inside

Garden power tools or extension leads — using indoor-rated extension leads outside lets moisture into the connections

Damaged or poorly routed cables — cables buried in the garden or clipped to external walls can crack over time, especially at joints

Outdoor junction boxes — non-weatherproof junction boxes on external walls are a very common culprit

Greenhouse or shed wiring — older DIY installations often lack proper weatherproofing

What you can safely do:

Note exactly which RCD trips — the label on your consumer unit will tell you which circuits it protects

Switch off and unplug all outdoor appliances and garden tools

Visually inspect outdoor sockets and lights for obvious water ingress, damaged covers, or cracked fittings — do not touch if wet

Try resetting the RCD once outdoor equipment is disconnected — if it holds, the fault is likely in that equipment

Do not keep resetting an RCD that trips repeatedly — this defeats its safety purpose

When to call a registered electrician:

The RCD still trips after disconnecting all outdoor equipment

You cannot identify the faulty circuit

There is visible water inside any socket or fitting

The installation is more than 10 years old and has never been inspected

You have any doubt whatsoever

Always use an electrician registered with a competent persons scheme such as NICEIC, NAPIT, or ELECSA. This work requires inspection and testing — it is not a job for guesswork.

Need a qualified electrician in North London? Electriman covers Mill Hill, Barnet, Finchley, Edgware, Enfield and surrounding areas. Call us on 07701 366 284 or get a free quote at www.electriman.co.uk

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.