Growatt Solar Inverter Troubleshooting And Error Codes

As a homeowner, you’ve made the wise decision to harness the power of the sun with a Growatt solar inverter. This reliable piece of technology is crucial in converting the DC power generated by your solar panels into usable AC power for your home. However, like any piece of technology, it can sometimes encounter issues that need troubleshooting.

Understanding these issues and their corresponding error codes can help you identify the problem and take the necessary steps to resolve it. Whether you’re a seasoned solar energy user or new to the game, this guide will provide you with comprehensive information on Growatt inverter error codes and troubleshooting steps.

Quick Summary

Growatt Solar Inverters are reliable devices, but they can sometimes display error codes indicating issues that need attention. Understanding these codes and how to troubleshoot them can help ensure your solar system continues to function optimally.

Common Growatt Solar Inverter Error Codes

Growatt inverters come with a digital display that shows various error codes when there’s a problem. These codes are designed to help you identify the issue quickly and take appropriate action.

Here are some of the most common error codes you might encounter:

1) On-Grid Growatt Inverter Codes (PV → Grid)

These are the kinds of codes you’ll commonly see on on-grid units:

PV / DC Side

• Growatt Inverter Error 202 — PV voltage too high

What it usually means: The PV string voltage has exceeded what the inverter is designed to handle.
Likely causes: incorrect string design (too many panels in series), very cold mornings pushing Voc up, wrong inverter selection for the array.
What we do: confirm panel count, check Voc calculations, verify inverter max DC rating, inspect string layout.

• Growatt Inverter Error 203 — PV insulation resistance too low

What it usually means: insulation resistance to earth is below threshold.
Likely causes: water in rooftop isolator, damaged DC cable, crushed conduit, moisture in junctions, failing PV module bypass box.
What we do: insulation resistance testing (megger) per string, isolate fault location safely.

Grid / AC Side

• Growatt Inverter Error 300 — AC voltage out of range

What it usually means: the grid voltage is outside permitted limits (high or low).
Likely causes: local grid running high during midday solar export, undersized/long mains cable run, poor neutral connection, supply faults.
What we do: record voltage at inverter terminals under load, check MEN/neutral integrity, review export limiting if required.

Internal (DC Bus / Hardware Condition)

• Growatt Inverter Error 409 — abnormal bus voltage

What it usually means: inverter’s internal DC bus is outside normal operating range.
Likely causes: sometimes inverter hardware, sometimes triggered by unstable input/supply conditions.
What we do: confirm stable AC supply, inspect DC input stability, check logs, and if persistent, treat as a service/repair scenario.

Common Warnings

• Growatt Inverter Warning 400 — fan fault

What it usually means: cooling fan isn’t operating as expected.
Risks: overheating and derating, then shutdown.
What we do: verify fan operation, clear dust, check ventilation, replace fan if required.

• Growatt Inverter Warning 202 — SPD fault alarm (where fitted)

What it usually means: surge protection device has triggered/failed (depends on model and where SPD is installed).
What we do: inspect SPD status indicator, verify earthing, replace SPD module if applicable.

Electrician note: These code numbers and meanings can vary slightly by firmware. Always confirm against the model-specific manual—especially for internal/bus faults.

2) Growatt Hybrid / Storage Inverters (PV + Battery)

Hybrid units can throw codes that look similar to on-grid codes, but they also include “grid present/absent” logic because the inverter has to manage charging, discharge, and sometimes backup output modes.

• Growatt Inverter Error 302 — No AC connection

What it usually means: the inverter isn’t detecting grid/mains at its AC terminals.
Likely causes: tripped breaker, isolator off, wiring fault, grid outage, loose AC connection.
What we do: confirm AC isolator and breaker, measure voltage at AC input, confirm correct wiring and torque, verify no upstream protection has opened.

3) Growatt Off-Grid Inverters (Often “Fault XX” Codes)

Off-grid units commonly report faults like:

• Growatt Inverter Fault 03 — battery voltage too high

Likely causes: incorrect battery settings, BMS comms issue, charger regulation issue, wrong battery type profile.
What we do: check battery chemistry settings, verify BMS communication, review charge parameters.

• Growatt Inverter Fault 05 — output short circuit

Likely causes: downstream wiring fault, appliance fault, shorted circuit on backup loads.
What we do: isolate loads, insulation test circuits, reintroduce loads progressively.

• Growatt Inverter Fault 06 — output voltage too high

Likely causes: regulation/control issue, load conditions, configuration.
What we do: confirm output settings, check load behaviour, check firmware/service notes.

Electrician note: Off-grid troubleshooting is heavily dependent on the battery type, BMS compatibility, and system wiring topology.

Troubleshooting Growatt Solar Inverter Error Codes

When an error code appears on your Growatt inverter, it’s important to know how to troubleshoot the issue. Some problems can be resolved by resetting the inverter or checking the connections, while others may require professional solar inverter repairs.

The Correct Reset Procedure (So You Don’t Create More Faults)

A proper restart matters. The “quick off/on” approach can confuse fault logging and leave capacitors charged.

A typical safe sequence (varies by model, follow the label/manual):

• Turn AC isolator OFF
• Turn DC isolator OFF
• Wait 3–5 minutes (allow internal discharge)
• Turn DC ON first
• Turn AC ON second
• Allow 2–5 minutes for sync/restart

If the fault returns immediately, don’t keep cycling it – you’re just stressing components.

When You Should Call a Licensed Solar Electrician

While understanding your Growatt solar inverter error codes is useful, some issues require professional attention. If you’re unable to resolve the issue yourself or if the error code persists after troubleshooting, it’s best to seek help from Sydney solar repair specialists for assistance if:

• the inverter repeatedly shows insulation-related errors (common water ingress risk),
• there’s an internal bus / hardware fault that persists after a correct restart,
• you have grid voltage errors daily (export limiting / supply investigation may be needed),
• there’s burning smell, heat damage, melted isolator, or visible corrosion,
• or your system is hybrid/off-grid and you’re seeing battery-related faults (settings + BMS comms must be correct).

Professional solar technicians have the knowledge and tools to diagnose and resolve why your Growatt inverter isn’t working, ensuring your solar system continues to provide reliable, clean energy for your home.

Maintaining Your Growatt Solar Inverter

Regular maintenance is key to ensuring your Growatt solar inverter continues to function optimally. This includes regular solar panel servicing, cleaning, and checking for any visible damage or wear and tear.

It’s also important to monitor the performance of your solar system regularly. If you notice a significant drop in power output or frequent error codes, it may be time for solar panel repairs or even replacement.

Conclusion

Understanding Growatt Solar Inverter error codes and troubleshooting methods can help you maintain the efficiency of your solar system. However, when in doubt, always seek professional assistance to avoid causing further damage to your system.

At Solar Repair Sydney, we’re here to help with all your solar needs. Whether it’s regular maintenance, troubleshooting error codes, or carrying out necessary repairs, our team of experienced technicians is just a call away. Harness the power of the sun with confidence, knowing that we’ve got your back.