Why Does My RCD Keep Tripping? Causes & What to Do
Quick Answer
An RCD (safety switch) trips to protect you from electric shock when it detects current leaking to earth. Repeated tripping usually means a faulty appliance, damp or damaged wiring, or an overloaded circuit is triggering it — not a fault with the RCD itself in most cases. If it trips once and resets normally, it may have done its job correctly. If it trips repeatedly or won't reset, it's time to call an electrician.
What Could Be Causing the Problem?
- A faulty appliance plugged into that circuit (common culprits: heaters, kettles, washing machines, outdoor equipment)
- Moisture getting into an outdoor power point, light fitting or cable
- Damaged or ageing wiring insulation allowing current to leak to earth
- Too many appliances running on one circuit at once
- A fault in the RCD itself (less common, but possible on older units)
What Can I Safely Check?
- Unplug all appliances from the affected circuit, then try resetting the switch — if it holds, plug appliances back in one at a time to identify which one trips it
- Note whether the trip happens at a particular time of day or with a specific appliance (e.g. only when it rains, only when the kettle is on)
- Check if the trip affects the whole house or just one area — this can indicate whether it's a single appliance or a wider circuit issue
- Look for any obviously damaged power leads or plugs (frayed cords, cracked casings) and stop using them
When Should I Call an Electrician?
- The RCD won't reset at all, or trips again immediately
- It trips repeatedly with no obvious appliance causing it
- You notice burning smells, discolouration, or warmth around the switchboard
- The trips started after recent storms, flooding, or water exposure
- You're not confident isolating which appliance is responsible
What Will an Electrician Check?
- Test each circuit individually to isolate the fault using proper testing equipment
- Check insulation resistance on wiring to detect leakage to earth
- Inspect the RCD itself and the switchboard for wear, damage or incorrect wiring
- Identify and safely repair or replace the faulty appliance connection, cable or fitting
- Confirm the switchboard has the correct number and type of safety switches for full protection
FAQs
Frequently asked questions
Is it dangerous if my RCD keeps tripping?
The RCD tripping is actually a safety feature working correctly — it's protecting you from a potential shock. The risk comes from ignoring repeated trips rather than the trip itself, since it usually points to a real fault that needs fixing.
Can I just turn the RCD back on and ignore it if it doesn't trip again?
If it happened once and hasn't recurred, that's less concerning, but repeated tripping should always be investigated, even if it seems to settle down afterwards.
Why does my RCD only trip when it rains?
This is a classic sign of water getting into an outdoor circuit — a light fitting, power point, or cable — and should be checked by an electrician before it causes further damage.
Do all homes need RCDs?
Current WA regulations require safety switches on power and lighting circuits in most homes, particularly where any recent electrical work has been carried out.
Can a faulty RCD itself cause tripping?
Yes, on older switchboards the RCD unit itself can become faulty over time and may need replacing, which an electrician can confirm during testing.
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