Why does my RCD trip at night – Advice from Electriman, North London Electricians

Why Does My RCD Keep Tripping at Night?

An RCD (Residual Current Device) is a life-saving safety device in your consumer unit (fusebox). It monitors electrical current flowing in and out of a circuit, and if it detects even a tiny imbalance — as little as 30 milliamps — it cuts the power in milliseconds to protect you from electric shock or fire.

When it trips specifically at night, it usually means something is turning itself on after you've gone to bed and creating a small electrical fault called earth leakage.

Most Common Causes

Fridge or freezer compressor cycling — these switch on and off automatically and can develop faulty heater elements or worn insulation over time

Overnight heating systems — electric storage heaters, boilers, or underfloor heating timers activating on a schedule

Dishwashers or washing machines set on a delay timer programme

Outdoor lighting or sockets — moisture ingress into external fittings is worse overnight as temperatures drop

Ageing wiring — insulation resistance drops as cables cool down at night, especially in older properties

Garden water features or pond pumps — these can allow moisture into the circuit overnight

What You Can Safely Do

1. Note the time the trip occurs — this helps identify the appliance if it's on a timer

2. Unplug all appliances on the tripping circuit before bed

3. Reset the RCD — if it holds with everything unplugged, plug appliances back in one at a time over successive nights to identify the culprit

4. Check outdoor sockets and lights for visible water or damage

5. Check the appliance — if a specific item causes the trip, stop using it immediately

When to Call an Electrician

The RCD trips with nothing plugged in

It trips multiple times per night

You notice burning smells, scorch marks, or buzzing from your consumer unit

The property has older wiring (rubber-insulated cables, no earth sleeving)

The fault started after building work or rain

Never tape an RCD in the ON position or replace it with a standard MCB — this removes critical protection and is a serious safety hazard.

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.