Why Does My RCD Keep Tripping?

What the device is doing

An RCD, and many RCBOs, monitor the balance between the live and neutral current. A leak to earth, through a person, damp equipment or damaged cable, upsets that balance and the device switches off. That is the protection working. Resetting it does not remove the leak.

Likely causes

• A faulty or wet appliance. Kettles, outdoor equipment, irons and fridge compressors are common starting points.
• Moisture in an outside socket, a light or a junction.
• Damaged cable, including cable pierced by a nail or screw, or crushed in a door.
• A neutral-to-earth fault, which needs test equipment to find.
• Several small leaks that together are enough to trip a shared RCD.

A safe first check

Switch off and unplug portable appliances on the affected circuits. Reset the RCD once. If it stays on, plug things back in one at a time until it trips again. That appliance should stay unplugged.

If the RCD trips immediately with the appliances unplugged, or trips again as soon as a circuit is switched on, stop. Leave it off and ask an electrician. Do not keep resetting it, and do not open the consumer unit.

Fire, shock and a power cut

Call 999 if there is fire, smoke, or someone has had a shock and needs urgent help. The NHS guidance on calling 999 is for life-threatening emergencies. If the whole street is dark and your RCD has not tripped, the supply itself may be off. You can report a power cut on 105. That number does not find a fault inside your consumer unit.

Getting it investigated

Describe which device tripped, whether it stays on, and what you had plugged in. Use the emergency electrician page if the power will not stay on or you can smell burning. Use electrical fault finding if the trip is occasional and the installation is safe to leave. The firm you choose agrees the price. This site does not.