Critical

F31

Bus voltage is too high.

7 Devices that report this code

What does the F31 error code mean?

F31 on a Felicity unit indicates: Bus voltage is too high.. It is a critical-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 critical-severity code

Critical codes trip the unit offline immediately. They typically indicate hardware failure (short-circuit, IGBT, BMS) or an unsafe operating condition. Do not bypass the fault — note the code and contact authorized service.

What triggers this code

F31 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
F31Bus voltage is too high.Critical
Description

Bus voltage is too high; AC surge or internal components failed.

Cause

AC Surge or internal components failed.

Recommended fix

Restart the unit, if the error persists, contact the repair center.

Source:Apollo-5KLP1G01-All-in-one-ESS-User-Guide.pdf · page 43
IVEM 6048Inverter↗ view on device
F31Over temperature happen at convert H circuit.Fault
Description

Fault: Over temperature happen at convert H circuit.

Cause

The temperature of internal convert H 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 38
IVEM8048-IIInverter↗ view on device
F31Over temperature happen at convert H circuit.Fault
Description

Fault: Over temperature happen at convert H circuit.

Cause

The temperature of internal convert H 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 44
IVEM8048-LVInverter↗ view on device
F31Over temperature happen at convert H circuit.Fault
Description

Over temperature happen at convert H circuit.

Cause

The temperature of internal convert H 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 39
T-REX-10KHP3G01Inverter↗ view on device
F31Bus voltage is too high.Fault
Description

DC bus voltage exceeds permitted level.

Cause

AC Surge or internal components failed.

Recommended fix

Restart the unit, if the error persists, contact the repair center.

Source:T-REX-10KHP3G01-Inverter-User-Guide.pdf · page 29
T-REX-10KLP3G01Inverter↗ view on device
F31Bus voltage is too high.Critical
Description

Bus voltage is too high.

Cause

AC Surge or internal components failed.

Recommended fix

Restart the unit, if the error persists, contact the repair center.

Source:T-REX-10KLP3G01-Inverter-User-Guide.pdf · page 28
T-REX-50KHP3G01Inverter↗ view on device
F31Battery 2 soft start fault.Fault
Description

Battery 2 fails to raise the input voltage normally, shutdown and restart.

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

Frequently asked about F31

What is the F31 error on Felicity?
F31 on a Felicity unit means: Bus voltage is too high.. 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 F31 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 F31 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.