Can I clear the 43 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 43 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

43

Q: What does 43 mean on T-REX-3KLP1G01?

Parallel CAN COMM abnormality. Recommended fix: Test the parallel communication line, restart still have problems please contact the after-sales service.

BUS under voltage fault.

2 Devices that report this code

What does the 43 error code mean?

43 on a Felicity unit indicates: BUS under voltage fault.. It is a fault-severity event that can appear on 2 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

43 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.

IVGM5KL-P1G1Inverter↗ view on device

43BUS under voltage fault.Fault

Description

When the power grid experiences an AC power outage, the device detects islanding proactively.

Recommended fix

1. Restart the system 2~3 times; 2. if the fault still exists, please contact us for help.

Source:Felicitysolar IVGM Series Hybrid inverter Instruction Manual.pdf · page 52Felicitysolar IVGM Series Hybrid inverter Instruction Manual.pdf · page 54

T-REX-3KLP1G01Inverter↗ view on device

43Parallel CAN COMM abnormality.Fault

Description

Parallel CAN COMM abnormality.

Recommended fix

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

Source:T-REX-3_3.6_4_4.6_5_6KLP1G01-hybrid-inverter-user-guide-English.pdf · page 39

Frequently asked about 43

What is the 43 error on Felicity?: 43 on a Felicity unit means: BUS under voltage fault.. It can appear on 2 different devices in the Felicity catalog. The cause and recommended fix are listed for each device on this page.
Can I clear the 43 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 43 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.