How do I clear or fix error W15?

Power down the inverter and let it cool. Inspect cooling vents and fan inlets for dust, leaves, or insect nests — clean with compressed air.

W15

Felicity inverter error W15

Radiator overtemperature derating alarm

Fault — the inverter cuts its output and the red LED stays solid until the fault is cleared.

T-REX-50KHP3G01

InverterFault

What it means

Radiator overtemperature derating alarm — The radiator temperature is too high, and the inverter reduces the power.

Cause: Inverter internal temperature has exceeded the safe operating threshold. Causes include high ambient temperature, blocked cooling vents, failed cooling fan, or installation in direct sunlight.

How to fix it

Power down the inverter and let it cool.
Inspect cooling vents and fan inlets for dust, leaves, or insect nests — clean with compressed air.
Confirm the inverter is installed in a shaded, ventilated location with the manufacturer's required clearances on all sides.
If the fan does not spin on restart, fan replacement is required.

Source: T-REX-50KHP3G01-user-manual-.pdf, p.45

Frequently asked questions

What does error W15 mean on a Felicity inverter?: W15 means: Radiator overtemperature derating alarm. Inverter internal temperature has exceeded the safe operating threshold. Causes include high ambient temperature, blocked cooling vents, failed cooling fan, or installation in direct sunlight.
Is error W15 a fault or a warning?: W15 is a fault code: the inverter cuts its output and the red LED stays solid until it is cleared.
How do I clear or fix error W15?: Power down the inverter and let it cool. Inspect cooling vents and fan inlets for dust, leaves, or insect nests — clean with compressed air.

Related error codes

Other codes on the T-REX-50KHP3G01

All T-REX-50KHP3G01 codes

Prefer the full written guide? Read the complete Felicity inverter error-code guide

Compiled from official Felicity user manuals. Always consult your device manual and a qualified technician before performing repairs.