RCD Keeps Tripping Causes and Fixes

An RCD that trips the moment you reset it is usually telling a different story from one that trips after ten minutes, only in wet weather, or only when a specific load is used. Before opening accessories or disconnecting circuits, work out whether the trip is immediate, load-related, random, or linked to one item of equipment.

That first read on the problem helps you avoid blind testing. If the whole bank drops when one outdoor circuit is energised, the likely causes are different from a board that trips overnight with no obvious demand on it.

If you need to explain the protection side of the board to the client, RCD types explained is a useful companion page.

The best fixes are rarely glamorous. Dry and remake the outdoor joint. Replace the damaged fitting. Split a heavily loaded bank onto individual RCBOs. Correct the borrowed neutral. Replace the faulty accessory. Tighten the diagnosis first, then make the smallest sound fix that removes the fault and gives the client a safer installation.

If the visit leads to remedial work, the paperwork should show the fault found, the work completed, and the test result after the repair. If the client declines further work or the fault could not be fully traced in the time available, say that clearly and record the limitation.

For certificate-driven jobs, link the remedial note back to the EICR certificate workflow or to a follow-on consumer unit upgrade guide if the fix is really about poor circuit separation rather than one defective accessory.