W03Fault

Felicity inverter error W03

Power is zero

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

Severity differs by model — check your model below.

The exact meaning depends on your model:

E-CHO-SI3KS2

InverterFault

Also applies to:E-CHO-SI5KS2E-CHO-SI8KS2

What it means

Power is zero — Output power is zero.

Cause: The inverter is running but output power is zero: there is no usable PV input (night, disconnected or heavily shaded strings) or output is being held at zero by an export limit or remote instruction.

How to fix it

  1. Power down the inverter, wait 5 minutes for capacitors to discharge, then restart.
  2. If the fault recurs immediately or repeatedly, record the exact code and contact your installer or the manufacturer's service line.

Source: E-CHO-SI3KS2-Operation-Manual.pdf, p.17 · E-CHO-SI5KS2-Operation-Manual.pdf · E-CHO-SI8KS2-Operation-Manual.pdf

IVEM 6048

InverterWarning

Also applies to:IVEM6048

What it means

Low battery — Warning: Low battery. Beep once every second.

Cause: The battery voltage is too low.

How to fix it

The battery voltage is too low, it should be charging.

Source: felicitysolar IVEM 6048 Solar Inverter User Guide.pdf, p.36

IVEM8048-II

InverterWarning

Also applies to:IVEM12048-IIIVEM 8K-12K Series II

What it means

Low battery — Warning: Low battery. Beep once every second.

Cause: Battery voltage is too low.

How to fix it

The battery voltage is too low, it should be charging.

Source: IVEM8K-12K-II_compressed.pdf, p.42

IVEM8048-LV

InverterWarning

Also applies to:IVEM8048

What it means

Low battery — Warning: Low battery. Beep once every second.

Cause: The battery voltage is too low.

How to fix it

It should be charging.

Source: FelicitySolar IVEM8048-LV Single Phase Hybrid Inverter User Guide.pdf, p.37

T-REX-50KHP3G01

InverterFault

What it means

Battery 1 undervoltage alarm — Battery 1 voltage is too low, the battery should be charged.

Cause: Battery 1 voltage has fallen to the undervoltage alarm threshold — the warning stage before the undervoltage fault; the pack should be charged.

How to fix it

  1. Power down the inverter, wait 5 minutes for capacitors to discharge, then restart.
  2. If the fault recurs immediately or repeatedly, record the exact code and contact your installer or the manufacturer's service line.

Source: T-REX-50KHP3G01-user-manual-.pdf, p.44

Frequently asked questions

What does error W03 mean on a Felicity inverter?
It depends on the model — 7 devices use code W03. On the E-CHO-SI3KS2 it means: Power is zero. The card for each model on this page gives its exact meaning and fix.
Is error W03 a fault or a warning?
It depends on the model: on some models W03 is a fault (output cut, red LED solid), on others a warning (red LED flashing, unit keeps running). Check the card for your model on this page.
How do I clear or fix error W03?
Power down the inverter, wait 5 minutes for capacitors to discharge, then restart. If the fault recurs immediately or repeatedly, record the exact code and contact your installer or the manufacturer's service line. The exact steps for each affected model are listed on this page.

Related error codes

Other codes on the E-CHO-SI3KS2

All E-CHO-SI3KS2 codes All E-CHO-SI5KS2 codes All E-CHO-SI8KS2 codes

Other codes on the IVEM 6048

All IVEM 6048 codes

Other codes on the IVEM8048-II

All IVEM8048-II codes

Other codes on the IVEM8048-LV

All IVEM8048-LV 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.