Can I clear the F20 code myself?

It depends on the severity. Warning-level codes can usually be cleared by following the recommended fix. Fault and critical codes often require checking the source condition first; if the code returns immediately after restart, escalate to authorized service.

Is the F20 fix the same on every device?

The cause is consistent — it's the same protection logic. The exact fix wording can differ per device because each official manual addresses model-specific context (input ranges, parallel-config notes, firmware revisions). Use the per-device section that matches your unit.

Where does this information come from?

Every entry is sourced directly from the official Felicity user manual for the affected device. The "Source" line at the bottom of each device's section shows the manual filename and page number.

Fault

F20

Q: What does F20 mean on Apollo-5KLP1G01-MX?

Input and output wiring reversed. Cause: Input output reverse. Recommended fix: Confirm that the input and output wiring is correct.

Q: What does F20 mean on IVEM 6048?

Fault: Over temperature happen at inverter circuit. Cause: The temperature of internal inverter component is over the limitation. Recommended fix: Check whether the air flow of the unit is blocked or whether the ambient temperature is too high.

Q: What does F20 mean on IVEM8048-II?

Fault: Over temperature happen at INV circuit. Cause: The temperature of internal INV component is over the limitation. Recommended fix: Check whether the air flow of the unit is blocked or whether the ambient temperature is too high.

Q: What does F20 mean on IVEM8048-LV?

Over temperature happen at INV circuit. Cause: The temperature of internal INV component is over the limitation. Recommended fix: Check whether the air flow of the unit is blocked or whether the ambient temperature is too high.

Q: What does F20 mean on T-REX-10KHP3G01?

Input and output wiring is reversed. Recommended fix: Confirm that the input and output wiring is correct.

Input output reverse.

6 Devices that report this code

What does the F20 error code mean?

F20 on a Felicity unit indicates: Input output reverse.. It is a fault-severity event that can appear on 6 different devices in the Felicity catalog. The same code may have slightly different recommended fixes depending on the device — the per-device sections below show the exact wording from each device's official manual.

This is a fault-severity code

Fault codes stop normal operation but the unit may attempt to recover. Common causes are out-of-range conditions (voltage, current, temperature) that require checking inputs and outputs before restart.

What triggers this code

F20 is triggered when the unit's protection or monitoring logic detects the specific condition described above. The exact trigger depends on the device — see the per-device sections for the official manual entry for each.

Apollo-5KLP1G01-MXEnergy storage system↗ view on device

F20Input output reverse.Fault

Description

Input and output wiring reversed.

Cause

Input output reverse.

Recommended fix

Confirm that the input and output wiring is correct.

Source:Apollo-5KLP1G01-All-in-one-ESS-User-Guide.pdf · page 43

IVEM 6048Inverter↗ view on device

F20Over temperature happen at inverter circuit.Fault

Description

Fault: Over temperature happen at inverter circuit.

Cause

The temperature of internal inverter component is over the limitation.

Recommended fix

Check whether the air flow of the unit is blocked or whether the ambient temperature is too high.

Source:felicitysolar IVEM 6048 Solar Inverter User Guide.pdf · page 37

IVEM8048-IIInverter↗ view on device

F20Over temperature happen at INV circuit.Fault

Description

Fault: Over temperature happen at INV circuit.

Cause

The temperature of internal INV component is over the limitation.

Recommended fix

Check whether the air flow of the unit is blocked or whether the ambient temperature is too high.

Source:IVEM8K-12K-II_compressed.pdf · page 43

IVEM8048-LVInverter↗ view on device

F20Over temperature happen at INV circuit.Fault

Description

Over temperature happen at INV circuit.

Cause

The temperature of internal INV component is over the limitation.

Recommended fix

Check whether the air flow of the unit is blocked or whether the ambient temperature is too high.

Source:FelicitySolar IVEM8048-LV Single Phase Hybrid Inverter User Guide.pdf · page 38

T-REX-10KHP3G01Inverter↗ view on device

F20Input output reverse.Critical

Description

Input and output wiring is reversed.

Recommended fix

Confirm that the input and output wiring is correct.

Source:T-REX-10KHP3G01-Inverter-User-Guide.pdf · page 28

T-REX-50KHP3G01Inverter↗ view on device

F20Battery 1 software overcurrent fault.Fault

Description

Battery 1 current is too large, check the battery charge and discharge power.

Source:T-REX-50KHP3G01-user-manual-.pdf · page 46

Frequently asked about F20

What is the F20 error on Felicity?: F20 on a Felicity unit means: Input output reverse.. It can appear on 6 different devices in the Felicity catalog. The cause and recommended fix are listed for each device on this page.
Can I clear the F20 code myself?: It depends on the severity. Warning-level codes can usually be cleared by following the recommended fix. Fault and critical codes often require checking the source condition first; if the code returns immediately after restart, escalate to authorized service.
Is the F20 fix the same on every device?: The cause is consistent — it's the same protection logic. The exact fix wording can differ per device because each official manual addresses model-specific context (input ranges, parallel-config notes, firmware revisions). Use the per-device section that matches your unit.
Where does this information come from?: Every entry is sourced directly from the official Felicity user manual for the affected device. The "Source" line at the bottom of each device's section shows the manual filename and page number.

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