The most common causes of nuisance tripping and when to call an electrician.
Updated July 1, 2026·5 min read
Quick answer
Why your RCD keeps tripping and how to fix it
The most common causes of nuisance tripping and when to call an electrician.
What the RCD does
An RCD protects against leakage current and electric-shock risk. If it trips, treat it as a safety signal with a cause that needs evidence, not as a nuisance to bypass.
What you can observe without touching the installation
Record when it happens, which appliances were running, whether there was damp or rain, and whether any recent work was completed. Do not open the consumer unit, remove covers, bypass protection or repeatedly force the fault to appear.
When to arrange an inspection
If tripping recurs, a professional should test insulation, leakage and protective-device operation on site. If there is smoke, a burning smell, sparks, unusual heat or shock risk, keep away and seek urgent help.
A residual-current device that trips: Facts that change the decision
Before deciding, collect when it trips, connected circuits, appliances in use and recent changes to the installation. A useful survey or study explains how those inputs were obtained and the limits of its estimate.
The answer changes with moisture, one appliance, a recent extension or ageing cables. Ask for a base scenario and another showing the effect of changed conditions.
Provide twelve months of bills or consumption readings where available.
Ask for access, space and capacity constraints to be identified in writing.
Check that equipment brands and model references match the technical sheets.
A residual-current device that trips: Evidence, scope and rules
Request a professional test record, insulation measurements and the condition of protective devices. The scope, exclusions and responsibility for each procedure should be unambiguous.
The REBT sets the protection framework; finding a specific cause needs a qualified on-site inspection. Do not replace documentary checks with a sales explanation.
Request a timetable separating survey, work, testing and document handover.
Keep drawings, work photographs, serial numbers and certificates received.
Confirm in writing which authorised professional signs where the work requires it.
A residual-current device that trips: Compare without shortcuts
A common mistake is resetting it repeatedly or bypassing protection to keep a circuit live. Compare equivalent proposals rather than headlines, and ask which assumption explains every difference.
A more complete option may be preferable even when it is not the shortest to read. Where there is electrical risk, do not manipulate anything to test a theory; arrange qualified help.
Compare materials, protective devices, labour and paperwork as separate items.
Ask which specific condition can create an extra charge and how approval works.
Review product and workmanship warranty as well as the fault-contact route.
What to verify
Use this list to turn the guide into specific questions before approving any work.
Warning signs that mean you should stop touching the installation and seek urgent help.
Included protective devices, tests and safety measures.
Installer authorisation for the work and any required certificates.
Exact scope, exclusions and final outcome in writing.
Itemised price, taxes, travel and possible extras.
Frequently asked questions
Is it dangerous when the RCD trips?
No, that is its safety function. The danger is the leakage causing it, which is why the cause should be fixed.
Can I bypass the RCD temporarily?
Never. Disabling the RCD removes protection against electrocution and is very dangerous.
Official source
Sources and regulations
Primary public sources used for the regulatory and administrative framework. Always check the current version and the procedure that applies to your case.