Deye F18 fault: AC over-current (hardware)

What it means

The inverter saw a sudden surge of current on its AC side and protected itself. A heavy appliance starting up is a common trigger.

Likely causes

• Large motor or appliance starting up
• Too many loads on the backup side
• Internal hardware fault if it repeats

What you can safely check

1. Switch off or unplug heavy appliances (kettle, heater, geyser, pool pump) on the backup circuits.
2. Restart the inverter once using its documented switch-off and switch-on procedure.
3. If it keeps coming back, stop and call a qualified installer.

When to call a pro

If it doesn't clear on its own, happens often, or comes with burning smells, heat or noise, call a qualified installer.