Fault Code Reference

Solis Fault Codes

Solis hybrid and string inverters. Popular across UK residential installations, available through major distributors. Covers both legacy E-code and official alarm code ranges.

93

Fault codes

Device types covered

Inverter (93)

Common fault codes

Grid Over-Voltage

Measure grid voltage at inverter AC terminals with multimeter. UK nominal 230V —…

Grid Under-Voltage

Measure grid voltage at AC terminals. Check AC connections are tight and correct…

Grid Over-Frequency

Fault is usually transient — wait 5 minutes for auto-recovery. Check Solis app f…

Grid Under-Frequency

Usually transient — wait for auto-recovery. Persistent fault indicates grid or s…

Grid Impedance High

Check all AC connections are tight — consumer unit, inverter terminals, any junc…

PV Over-Voltage

Measure open-circuit string voltage with multimeter on a cold morning (highest V…

All Solis fault codes

Grid Over-Voltage

Measure grid voltage at inverter AC terminals with multimeter. UK nominal 230V —…

Grid Under-Voltage

Measure grid voltage at AC terminals. Check AC connections are tight and correct…

Grid Over-Frequency

Fault is usually transient — wait 5 minutes for auto-recovery. Check Solis app f…

Grid Under-Frequency

Usually transient — wait for auto-recovery. Persistent fault indicates grid or s…

Grid Impedance High

Check all AC connections are tight — consumer unit, inverter terminals, any junc…

PV Over-Voltage

Measure open-circuit string voltage with multimeter on a cold morning (highest V…

PV Input Polarity Reversed

De-energise system. Check DC cable polarity with multimeter before reconnecting …

Low Insulation Resistance

Check DC cables along full run for damage, crushing, or abrasion. Check panel ju…

MPPT Input Fault

Measure open-circuit voltage on each string individually. Both strings on same M…

Battery Communication Lost

Check CAN cable is connected to the correct port on both inverter (BAT CAN port)…

Battery Over-Voltage

Check inverter battery charge voltage setting matches battery specification. Dyn…

Battery Under-Voltage

Check inverter battery discharge cut-off voltage setting. Dyness Powerbox G2: mi…

Battery Over-Temperature

Check battery location — must be out of direct sunlight. Ambient temperature mus…

Battery Under-Temperature

This is a BMS protection — normal behaviour below 0°C. Battery will not charge u…

Battery Over-Current

Check inverter charge and discharge current limits. Dyness Powerbox G2: max 100A…

Battery BMS Fault

Check battery BMS status LEDs or display (Dyness Powerbox G2 has LED bar on fron…

Battery Brand Mismatch

In Solis app or inverter menu: go to Battery Settings. Set battery brand correct…

Inverter Over-Temperature

Check inverter location — must not be in direct sunlight. Minimum clearances: 30…

Power cycle: turn AC breaker OFF, then DC isolator OFF. Wait 5 minutes. Restore …

Firmware Fault / Version Mismatch

Check Solis app for available firmware update. If update interrupted, re-attempt

Power cycle inverter — AC OFF, DC OFF, wait 5 minutes, restore. Monitor for recu…

Export Limit Fault — CT Clamp

Locate export limit CT clamp — must be on grid incomer (DNO side of consumer uni…

Export Limit Exceeded

Check export limit setting in Solis app. G98 installs: typically 3.68 kW limit. …

Grid Overvoltage (Alarm 1010)

If occasional, let it auto-recover. Check the grid standard is set correctly for…

Grid Undervoltage (Alarm 1011)

Check the grid is present and the main breaker is on.

Grid Over-Frequency (Alarm 1012)

Check the grid standard setting. The inverter reconnects automatically when freq…

Grid Under-Frequency (Alarm 1013)

Check the grid standard setting. Auto-reconnects when frequency recovers.

AC Backfeed Current (Alarm 1014)

Restart the inverter.

No Grid (Alarm 1015)

Check the AC isolator and main breaker are on.

Unbalanced 3-Phase Grid (Alarm 1016)

Check all three phases are present and properly connected at the inverter.

Grid Frequency Fluctuating (Alarm 1017)

Confirm the grid connection is sound, then restart.

Grid Output Overcurrent (Alarm 1018)

Confirm the grid is normal and AC cables are properly connected, then restart.

Grid Current Tracking Error (Alarm 1019)

Restart the inverter.

Abnormal Grid Phase Angle (Alarm 101A)

Check AC side wiring and phase rotation.

Grid Interference (Alarm 1030)

Restart the inverter.

Grid Current Sampling Error (Alarm 1047)

Check AC connections are reliable, then restart.

Grid Current Transient Overcurrent (Alarm 1050)

Restart the inverter.

Grid Voltage Sampling Deviation (Alarm 1059)

Compare the AC voltage shown on the LCD with a multimeter reading at the termina…

Low Resistance L to PE (Alarm F017)

Check the AC side wiring for a ground fault.

DC Overvoltage (Alarm 1020)

Check string Voc against the inverter maximum input and count panels in series.

DC Boost Circuit Fault (Alarm 1020)

Restart the inverter.

DC Bus Overvoltage (Alarm 1021)

Check the PV input voltage is within the inverter range, then restart.

DC Bus Imbalance (Alarm 1022)

Restart the inverter.

DC Bus Undervoltage (Alarm 1023)

Check whether the input voltage is too low for the inverter to run.

DC1 Average Overcurrent (Alarm 1025)

Check the strings on MPPT 1 for faults and polarity.

DC2 Average Overcurrent (Alarm 1026)

Check the strings on MPPT 2 for faults and polarity.

Abnormal DC Input Current (Alarm 1027)

Check the DC wiring for poor connection or damage.

DC Reversed (Alarm 1028)

Isolate the system, then verify string polarity with a meter before reconnecting…

PV Midpoint Insulation Low (Alarm 1029)

Note the timing. Early morning, late afternoon or rainy day reports are usually …

DC Bus Sampling Fault (Alarm 102A)

Restart the inverter.

PV Insulation Protection (Alarm 1033)

Note the timing. Morning, late afternoon or rain reports are usually moisture an…

Leakage Current Protection (Alarm 1034)

Reconnect strings one at a time to find the faulty string.

DC Arc Detected (Alarm 1041)

Inspect MC4 connectors, inverter DC terminals, fuse blocks and junction boxes fo…

AFCI Self-Check Protection (Alarm 1040)

Restart the inverter.

Leakage Sensor Self-Check (Alarm 1039)

Restart the inverter.

DSP Initialising Fault (Alarm 1031)

Restart the inverter.

Overtemperature (Alarm 1032)

Check the install location against the manual, direct sun, mounting angle and cl…

Low Temperature (Alarm 103A)

Check the ambient temperature, then restart the inverter.

Relay Self-Check Fault (Alarm 1035)

Restart the inverter.

DSP Comms Fault (Alarm 1036)

Check the DSP software version exists on the LCD, then restart.

DC Injection Too High (Alarm 1037)

Confirm the grid and AC cables are normal, then restart.

12V Supply Fault (Alarm 1038)

Restart the inverter.

IGBT Overcurrent (Alarm 1048)

Restart the inverter.

DSP Firmware Mismatch (Alarm 1058)

Check the firmware version matches the inverter model number, then restart.

DSP Software Firmware Mismatch (Alarm 105A)

Check the 4th and 5th characters of the SN are consistent with the LCD model inf…

Battery Hardware Overvoltage (Alarm 1051)

Check whether the battery circuit breaker has tripped.

LLC Hardware Overcurrent (Alarm 1052)

Check whether the backup load is overloaded, reduce it.

Battery Overvoltage (Alarm 1053)

Check battery voltage against spec and battery settings, then restart.

Battery Undervoltage (Alarm 1054)

Check battery SOC and voltage. Force-charge from grid if deeply discharged.

Battery Not Connected (Alarm 1055)

Check the battery connections are sound.

Backup Voltage High (Alarm 1056)

Check the backup terminal wiring is correct.

Backup Overload (Alarm 1057)

Switch off some backup loads, especially inductive ones.

Battery CAN Comms Failure (Alarm 2012)

Check the CAN cable is seated at the inverter BAT port and the battery, with the…

Battery BMS Alarm 1 (Alarm 2015)

Restart the battery and check whether the fault returns.

Wrong Battery Brand Selected (Alarm 2016)

Check the selected battery brand on the inverter LCD matches the installed batte…

Battery BMS Alarm 2 (Alarm 2017)

Restart the battery and check whether the fault returns.

LG Battery BMS Fault (Alarm 2019)

Restart the battery.

LG Battery Comms Failure (Alarm 2021)

Check the comms cable, then restart the battery.

EPM Comms Failsafe (Alarm 2010)

Check the communication connection between the inverter and the EPM or meter.

Meter Comms Failure (Alarm 2011)

Check the meter communication cables.

DSP Comms Failure (Alarm 2014)

Restart the inverter and check whether the fault returns.

DRM Connection Failure (Alarm 2018)

Confirm the DRM cable connection is reliable, or disable DRM if not used.

CT Connection Lost

Check the CT cables to the EPM.

Meter Comms Abnormal (EPM)

Restart the EPM.

Meter Voltage Abnormal (EPM)

Restart the EPM.

RS485 Link Lost

Check the communication cables between the EPM and the affected inverters.

Internal Fan Fault

Check whether the internal fan starts, then restart the inverter.

External Fan Fault

Check the external fan, clean it per the manual.

DC Surge Protection Fault

Restart the inverter.

AC Surge Protection Fault

Restart the inverter.

Grid Surge Detected

No action needed if one-off. Restart if it keeps appearing.

Waiting (Status)

Check the DC input voltage reaches the minimum starting voltage in daylight.

Output Limited by EPM (Status)

Confirm whether export control is intended on this install. If yes, this is norm…

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