Why is my EV charger showing a no ground fault after heavy rain?
Quick answer
A ground fault or earth fault warning on your EV charger after heavy rain is most commonly caused by moisture ingress into the charger unit, the outdoor socket, or the cable connections. Water bridging the earth and live conductors triggers the internal ground fault circuit interrupter. Do not reset and ignore the fault. Switch off the charger at the consumer unit and leave it to dry out for 24 to 48 hours before retesting. If the fault persists or returns repeatedly, call a qualified electrician, as continued use risks electric shock.
🏠Homeowner view
What does a ground fault warning actually mean?
Your EV charger has a built-in safety device that constantly monitors the electrical path between the live conductors and the earth. When it detects current leaking to earth where it should not be, it shuts down and displays a ground fault or earth fault error. This is the charger doing exactly what it should, protecting you from electric shock.
Why does rain make it happen?
Outdoor EV chargers are designed to be weatherproof, but sustained heavy rain can overwhelm even well-installed equipment. The most common reasons this happens after rain are:
1. Water has entered the charger enclosure through a degraded seal or damaged gasket.
2. The outdoor trunking or conduit carrying the supply cable has filled with water and allowed moisture into a junction box or consumer unit.
3. The Type 2 or tethered charging socket has collected water in the connector itself.
4. A ground spike or earth rod connection has become waterlogged, temporarily altering earth impedance readings.
What you can safely check yourself
You should not open any electrical enclosures or attempt any wiring checks yourself. What you can safely do is:
Inspect the outside of the charger casing for visible cracks, damaged seals, or pooled water around the unit.
Check the charging cable and plug connector for visible moisture or corrosion.
Look at the conduit and trunking on the external wall for any splits or missing end caps that could let water in.
Leave the charger switched off at the consumer unit for 24 to 48 hours in dry conditions to allow passive drying.
When to call an electrician
Call a qualified electrician if the fault warning returns as soon as you restore power, if you can see water inside the enclosure viewing window, if you smell burning or notice any scorching, or if this is the second or third time this fault has appeared. Repeated moisture ingress is a sign of a failed IP rating, a wiring fault, or a charger that was not installed to the correct standard in the first place.