Can I clear the F44 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 F44 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

F44

Q: What does F44 mean on Apollo-5KLP1G01-MX?

Loss of parallel hosts in parallel system. Cause: Loss of parallel hosts. Recommended fix: Test the parallel communication line, restart still have problems please contact the after-sales service.

Q: What does F44 mean on T-REX-10KHP3G01?

Host data loss. Recommended fix: Check if communication cables are connected well and restart the inverter. if the problem remains, please contact your installer.

Q: What does F44 mean on T-REX-10KLP3G01?

Host data loss. Cause: Communication cables not connected well. Recommended fix: 1. Check if communication cables are connected well and restart the inverter. 2. if the problem remains, please contact your installer.

Loss of parallel hosts.

7 Devices that report this code

What does the F44 error code mean?

F44 on a Felicity unit indicates: Loss of parallel hosts.. It is a fault-severity event that can appear on 7 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

F44 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

F44Loss of parallel hosts.Fault

Description

Loss of parallel hosts in parallel system.

Cause

Loss of parallel hosts.

Recommended fix

Test the parallel communication line, restart still have problems please contact the after-sales service.

Source:Apollo-5KLP1G01-All-in-one-ESS-User-Guide.pdf · page 44

IVEM 6048Inverter↗ view on device

F44The firmware version of each inverter is not the same.Fault

Description

Fault: The firmware version of each inverter is not the same.

Cause

CPU/firmware versions differ between paralleled inverters.

Recommended fix

1. Update all inverter firmware to the same version. 2. Check the version of each inverter via LCD setting and make sure the CPU versions are same. if not, please contact your installer to provide the firmware to update. 3. After updating, if the problem still remains, please contact your installer.

Source:felicitysolar IVEM 6048 Solar Inverter User Guide.pdf · page 38

IVEM8048-IIInverter↗ view on device

F44The firmware version of each inverter is not the same.Fault

Description

Fault: The firmware version of each inverter is not the same.

Cause

Firmware versions on parallel inverters do not match.

Recommended fix

Source:IVEM8K-12K-II_compressed.pdf · page 45

IVEM8048-LVInverter↗ view on device

F44The firmware version of each inverter is not the same.Fault

Description

The firmware version of each inverter is not the same.

Cause

Mismatched firmware versions across paralleled inverters.

Recommended fix

Source:FelicitySolar IVEM8048-LV Single Phase Hybrid Inverter User Guide.pdf · page 39

T-REX-10KHP3G01Inverter↗ view on device

F44Host data loss.Fault

Description

Host data loss.

Recommended fix

Check if communication cables are connected well and restart the inverter. if the problem remains, please contact your installer.

Source:T-REX-10KHP3G01-Inverter-User-Guide.pdf · page 29

T-REX-10KLP3G01Inverter↗ view on device

F44Host data loss.Fault

Description

Host data loss.

Cause

Communication cables not connected well.

Recommended fix

1. Check if communication cables are connected well and restart the inverter. 2. if the problem remains, please contact your installer.

Source:T-REX-10KLP3G01-Inverter-User-Guide.pdf · page 29

T-REX-50KHP3G01Inverter↗ view on device

F44Inverter soft start fault.Fault

Description

Inverter voltage fails to rise normally at startup, shutdown and restart.

Source:T-REX-50KHP3G01-user-manual-.pdf · page 47

Frequently asked about F44

What is the F44 error on Felicity?: F44 on a Felicity unit means: Loss of parallel hosts.. It can appear on 7 different devices in the Felicity catalog. The cause and recommended fix are listed for each device on this page.
Can I clear the F44 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 F44 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.