Solis Inverter Alarm Codes: Master UK Fault List and Triage Guide

Key Takeaways

• Solis alarms are classified into three severity levels: Tip (self-recovering), General (requires inspection), and Emergency (system shutdown).
• The first diagnostic step is checking the historical log through the Advanced Info menu using passcode 0-0-1-0 to review the 100 latest alarm messages.
• Safety-critical alarms such as PV-ISO-PRO or DC arc faults require isolating both AC and DC supplies before any inspection of cables or connectors.
• Stop DIY troubleshooting immediately for internal component errors or recurring insulation trips, and contact your MCS-certified solar installer.

Why is my Solis inverter showing an alarm code or warning?

When an abnormal electrical condition occurs on a solar photovoltaic installation, the Solis inverter halts generation or alerts the operator via the front panel liquid crystal display and SolisCloud monitoring telemetry. The manufacturer diagnostic framework provides a standardized reference across grid-tied string inverters, energy storage systems, and battery subsystems.

Understanding the severity grade and fault category prevents premature component replacement and ensures compliance with UK distribution network regulations, including ENA EREC G98 grid connection standards. Faults are structured by hardware subsystem: utility grid parameters, direct-current solar array inputs, lithium energy storage banks, and inter-inverter communication networks.

How to access the Solis alarm history log

Before clearing alarms or restarting your system, you should extract the exact fault sequence from the internal memory. The inverter stores a rolling archive of operational alerts.

1. Enter the Main Menu: Press the "Enter" button to access Main Menu.
2. Navigate to Diagnostics: Scroll down to "Advanced Info."
3. Input Service Passcode: Enter pass code "0-0-1-0" (press "Down-Down-Up-Down"), then press "Enter."
4. Select Alarm Records: Within the "Advanced Info" submenu, select the first option, "Alarm Message." This will display the 100 latest alarm messages, along with the date and time they occurred.
5. Review and Exit: Scroll through the alarm messages manually by pressing the UP/DOWN buttons. Press the ESC button to return to the previous menu.

Record the primary alarm code along with any sub-codes and timestamps before resetting the system or scheduling on-site service.

Solis alarm severity grading system

Solis categorizes diagnostic messages into distinct severity levels to guide operational response:

Installers and system owners must treat insulation, arc fault, and battery emergency alarms as high priority.

Master Solis error code triage table

The following directory outlines the primary fault families across UK Solis installations:

For broader domestic wiring compliance across Great Britain, see our UK solar electrical installation guide.

Battery storage and communication fault triage

Energy storage hybrid models incorporate multi-level protection spanning battery voltage, current, operating temperature, and BMS digital communication. When battery alarms occur:

1. Verify BMS Link: If CAN-BUS-Lose or DCanErr appears, inspect the RJ45 data lead between the battery management unit and the inverter communication port.
2. Check Status Indicators: Confirm whether the battery power switch is on and note battery LED status.
3. Firmware Consistency: When running parallel inverters or modular battery towers, ensure all parallel systems run matching firmware versions.
4. Meter Communication: If energy monitoring is lost, verify communication wiring between the inverter and the generation meter. For export compliance, see our Smart Export Guarantee guide.

Safety rules for electrical diagnosis

Solar photovoltaic systems generate hazardous direct-current voltages whenever light strikes the solar modules.

• Isolate All Supplies First: Always open the AC circuit breaker in your consumer unit and turn off the external DC rotary isolator before inspecting terminals or plugs.
• Use Insulated Tools: Any terminal adjustment must be performed with insulated hand tools.
• Capacitor Discharge Time: After disconnecting all power sources, wait for internal capacitors to discharge before opening terminal covers.
• Emergency Alarm Protocol: Never override an emergency insulation or arc fault alarm without a comprehensive array inspection. For residential storage safety, review our UK battery storage fire safety guide.

When to contact an MCS-certified technician

While menu navigation and visual isolator checks are safe for system owners, physical circuit testing involves high voltage. Contact your certified installer if:

• The alarm code is classified as Emergency (such as PV-ISO-PRO or ARC-FAULT).
• The inverter displays an internal hardware error that persists across power cycles.
• You need to test open-circuit string voltages or perform high-voltage insulation tests.
• Always record alarm code + sub-code + device type when opening service tickets to expedite technical support.