RCD Keeps Tripping? Why Your Power Keeps Cutting Out and Which Causes Need an Auckland Electrician Today
An RCD trips because it's detecting current leaking somewhere it shouldn't — that's the device working, not failing. The pattern of when it trips is the clue: nothing plugged in points to wiring or the board itself; only at night often means the hot water cylinder or a fridge; on a specific circuit narrows it to one area; randomly and everywhere suggests moisture. Here's how to read it before you call.
Power out right now? Call 021 889 770 — don't keep resetting a board that keeps tripping, tell us the pattern and we'll diagnose it fast.
Read the pattern
Trips with nothing plugged in — points to the wiring itself or a fault at the board, not an appliance. Needs testing rather than guessing.
Trips only at night — often the hot water cylinder element or a fridge/freezer compressor cycling on, both common culprits
Trips on one lighting circuit specifically — usually a downlight, a damaged cable, or moisture in a ceiling fitting
Trips intermittently with no obvious trigger — the hardest to diagnose from the outside, and the one most worth booking a proper test for
Trips when it rains — moisture tracking into an outdoor fitting or joint; see our dedicated power tripping in the rain guide for that specific cause
Appliance fault or wiring fault?
A quick DIY check: switch off or unplug everything on the affected circuit, reset the RCD, then reintroduce items one at a time. If it trips again as soon as one specific appliance goes on, that's an appliance fault — stop using it and get it tested. If it trips with everything off, the fault is in the fixed wiring itself and needs an electrician to isolate which circuit and where.
No RCD at all on your board?
If your power never trips because there's no RCD fitted, that's a different and more serious gap — it means a fault that should trip a safety switch instantly simply won't. Older boards, particularly those with ceramic fuses, commonly have none. See our guide on old fuse boxes and what NZ rules require.
Frequently asked questions
Can I just keep resetting the RCD?
For a one-off, yes. If it keeps happening, no — you're repeatedly re-energising a circuit with an active fault, which is exactly what the RCD exists to prevent.
How much does a callout for a tripping RCD cost?
See our call-out fee guide for current rates — most tripping faults are found and fixed in a single visit.
Is a tripping RCD an emergency?
It's doing its job, so a single trip usually isn't. Call promptly if it won't reset at all, if you smell burning, or if it's affecting essential circuits like the fridge or hot water for an extended period.
Get it diagnosed properly
📞 Call 021 889 770 — describe the pattern, we'll advise next steps
📷 Text a photo of your board to 021 889 770
Registered electricians on current EWRB practising licences · Certificate of Compliance and Electrical Safety Certificate issued within the statutory 20 days · Based in Remuera, working Auckland-wide