RCD Doesn’t Stay Back On? Here’s Why It Keeps Tripping
What an RCD Actually Does
An RCD (Residual Current Device) is designed to protect you from electric shock.
It constantly monitors the balance between live and neutral current. If it detects
electricity leaking to earth — even a small amount — it trips instantly to cut power.
So if your RCD won’t stay back on, it’s usually doing its job and detecting a fault somewhere in the system.
A qualified Electrician in London
would always treat repeated RCD tripping as a sign that something needs investigating.
Why Your RCD Won’t Stay On
If the RCD trips immediately and won’t reset, there is likely an active earth leakage fault.
Common causes include:
- Faulty electrical appliance
- Damaged wiring
- Water ingress
- Overloaded circuits with leakage accumulation
- Neutral-to-earth faults
In split-load boards, one RCD may control multiple circuits, which makes identifying the fault more complex.
Faulty Appliances – The Most Common Cause
White goods such as washing machines, dishwashers and ovens are frequent culprits.
Internal heating elements can deteriorate and cause earth leakage.
Try unplugging all appliances on the affected circuits and then reset the RCD.
If it stays on, plug appliances back in one at a time to identify the faulty item.
Wiring or Earth Leakage Faults
If unplugging appliances doesn’t solve the issue, the problem may lie in fixed wiring.
Damaged cables, loose connections or insulation breakdown can all cause persistent tripping.
During London Landlord EICR Certificates,
these faults are often identified through insulation resistance testing.
Moisture and Outdoor Circuits
Outdoor sockets, garden lighting and sheds are particularly vulnerable to moisture ingress.
Rainwater inside fittings can create leakage paths that trip the RCD.
This is especially common during heavy rain or after flooding.
How to Safely Troubleshoot
- Switch off all MCBs protected by the RCD.
- Reset the RCD.
- Turn circuits back on one at a time.
- Identify which circuit causes the trip.
If the RCD still will not reset with all circuits off, the device itself could be faulty.
When to Call a Qualified Electrician
If you cannot identify the cause quickly, do not keep repeatedly forcing the RCD back on.
Persistent faults require professional testing equipment.
Contact London Emergency Electricians
if the RCD trips instantly, sparks are visible, or there is a burning smell.
Experienced London Electricians
use insulation resistance testers and earth leakage measurements to locate the issue safely.
Would RCBO Protection Solve the Problem?
If your consumer unit uses a split-load RCD system, one fault can shut down multiple circuits.
Upgrading to RCBO protection allows each circuit to trip individually, making fault finding easier
and reducing inconvenience.
While RCBOs won’t eliminate faults, they significantly improve circuit discrimination and safety.