It's incredibly frustrating when you're settling down for the evening and the power suddenly cuts out. If your RCD (Residual Current Device) keeps tripping, it’s doing its job to protect you from an electrical fault, but finding the root cause can be tricky.
What is an RCD?
An RCD is designed to instantly switch off the electricity if it detects a leak in the current. This life-saving device prevents fatal electric shocks and electrical fires.
Top 3 reasons your RCD is tripping
- Faulty appliances: The most common culprit. A defective kettle, iron, or washing machine can leak enough current to trip the board.
- Water ingress: Have you had heavy rain recently? Water getting into outdoor sockets or leaking through the roof into junction boxes will immediately short the circuit.
- Damaged wiring: Rodents chewing cables under the floorboards or old, degrading insulation can cause persistent tripping.
How to fix an RCD that won't stay up
First, try the process of elimination. Unplug absolutely everything in the house—don't just switch them off, pull the plugs out. Reset the RCD. If it holds, start plugging appliances back in one by one until it trips again. You've found your culprit!
If the RCD refuses to reset even with everything unplugged, you're dealing with a hardwired fault. At this stage, you need to call in a qualified electrician to run a diagnostic on the circuit. Expect to pay around £60-£90 for an initial call-out and fault-finding session.