Your Fronius inverter is trying to tell you something. Every state code displayed on the screen, in Solar.web, or via a service message notification corresponds to a specific condition the inverter has detected. Some codes clear themselves within minutes. Others need a qualified electrician.
Last reviewed: April 2026. State code lists verified against current Fronius Australia documentation and firmware releases. Contact PSW Life Support if your code is not listed or the recommended steps do not resolve the issue.
This guide covers every documented Fronius state code across the full model range installed in Australia:
- Primo GEN24 – single-phase hybrid
- Symo GEN24 – three-phase hybrid
- Verto – three-phase hybrid
- and the legacy IG, IG Plus, Galvo, Primo, Symo, Symo Advanced, Eco (all SnapINverter models)
Each code includes a plain-English description of the cause and what you should do about it.
Contents
How Fronius state codes work
Fronius organises state codes into classes based on severity. Understanding which class your code belongs to tells you a lot before you even look up the specific number.
For SnapINverter models:
Primo, Symo, Eco, Galvo, IG/IG Plus
State codes use a three-digit numbering system. The first digit indicates the class:
- 1xx codes — Grid parameter issues. Temporary. The grid voltage, frequency, or impedance is outside the inverter's permitted operating window. The inverter disconnects, monitors the grid for the prescribed observation period under AS 4777.2, and reconnects automatically once conditions normalise. No action required unless the code persists.
- 2xx codes — Grid monitoring (ENS) alerts. Higher priority than 1xx codes. These come from the integrated grid monitoring device and flag more serious mains supply issues. Some overlap with 1xx codes but are elevated because of their safety significance.
- 3xx codes — Operational status. Occur during normal grid feed-in and do not indicate hardware damage. Common examples include thermal derating, low DC input at dawn/dusk, and current sensor checks. The inverter typically recovers automatically.
- 4xx codes — Hardware or software faults. These require attention. Try a full system restart first (procedure below). If the code persists, contact PSW Life Support or a Fronius Service Partner. Do not attempt to open the inverter.
- 5xx codes — Informational warnings. Generally do not stop energy production. The code stays on the display until you acknowledge it by pressing the button. The inverter continues operating.
- 6xx codes — Mixed severity. Some are informational, others require service intervention. Check the specific code.
- 7xx codes — Control system and configuration. Relate to data recording, USB operations, firmware updates, and inverter configuration. May affect feed-in directly or indirectly depending on the specific code.
For GEN24 models:
Primo GEN24, Symo GEN24, Verto
GEN24 inverters use a four-digit numbering system and display codes differently. Because these models do not have a physical button display (or use a minimal LED-only interface), state codes appear as service messages in the Fronius Solar.web portal and app. The LED indicators on the front of the unit provide a general status:
- Red: Fault, feed-in stopped
- Orange: Warning or reduced output
- Green: Normal operation
Finding your state code
SnapINverter (Primo, Symo, Eco): Press the Enter button (far right) on the inverter display. The first line shows STATE followed by the number. If multiple codes are queued, press Enter again to scroll through them.
GEN24 / Verto: Log in to Fronius Solar.web (solarweb.com) or the Solar.web app. Navigate to your system and check “Service Messages” for active and historical state codes. You can also access the inverter’s local web interface by connecting to its Wi-Fi access point (touch the sensor on the front once; the right LED flashes blue) and entering 192.168.250.181 in your browser.
Before you start
Try a restart
Many Fronius state codes resolve with a standard system restart. Before contacting your installer, try this:
- Switch OFF the AC isolator (circuit breaker in your switchboard labelled “Solar” or “Inverter”)
- Switch OFF the DC isolator (rocker switch on the underside or side of the inverter)
- Wait at least five minutes. All LEDs on the inverter must be completely off
- Switch ON the DC isolator first
- Switch ON the AC isolator
If the code reappears after the restart, note the exact code number and the time it occurred, then look it up below.
Safety notice: Never open the inverter cover or disconnect DC connectors. DC cables from solar panels carry dangerous voltage during daylight. All work inside the inverter or on DC wiring is restricted to licensed electricians under Western Australian electrical safety legislation.
Class 1: 1xx
Grid parameter codes
These codes appear when the grid supply at your property is outside the inverter’s permitted operating range. In most cases, the inverter handles this automatically: it disconnects, waits for the grid monitoring period required by AS 4777.2, and reconnects when conditions return to normal.
In Perth and regional WA, codes 102 (high voltage) and 107 (frequency) are the most common 1xx codes. Grid voltage on the SWIS network can rise above nominal during high-solar-export periods, particularly in newer suburbs with high rooftop PV penetration. If you see these codes during the middle of the day and they clear by afternoon, this is likely a local network voltage issue.
| Code | Description | What to do |
|---|---|---|
101 | AC voltage outside permitted range | Automatic. If persistent, contact your installer to check grid voltage at the switchboard |
102 | AC voltage too high | Most common in Perth during peak solar hours. Usually clears by mid-afternoon. If persistent, your installer can request a Western Power network assessment or adjust volt-watt response settings (requires Fronius country setup code) |
103 | AC voltage too low | Check for grid outage. If persistent, contact your installer |
104 | AC frequency too high | Automatic. Rare in WA |
105 | AC grid outside permitted limits | Automatic. If persistent, contact your installer |
106 | AC frequency too low | Automatic. Rare in WA |
107 | AC frequency outside permitted limits | Automatic. Contact your installer if it appears daily |
108 | Island mode detected (anti-islanding trip) | The inverter detected a potential island condition and disconnected for safety. Automatic reconnection after monitoring period |
112 | RCMU fault (residual current monitoring unit) | Contact your installer. This is a safety-critical fault related to earth leakage detection |
Perth-specific context for code 102: Under AS 4777.2:2020, inverters installed on the SWIS must comply with volt-watt and volt-VAr response modes. Your Fronius inverter’s volt-watt response curve determines the voltage threshold at which it starts reducing output. If you see code 102 or 1112 (on GEN24 models) regularly around midday, your installer can adjust these thresholds within Western Power’s permitted range. This is a configuration change, not a fault.
Class 2: 2xx
Grid monitoring codes
| Code | Description | What to do |
|---|---|---|
201 | Grid voltage exceeds upper limit (ENS) | Check grid voltage. Contact your installer if persistent |
202 | Grid voltage below lower limit (ENS) | Check for localised outage. Contact your installer if persistent |
203 | Grid frequency exceeds upper limit (ENS) | Automatic in most cases. Contact your installer if persistent |
204 | Grid frequency below lower limit (ENS) | Automatic in most cases. Contact your installer if persistent |
205 | Mains impedance change detected | Indicates serious grid disturbance. Contact your installer |
206 | Grid supply not available | Check your main switchboard circuit breakers. Confirm there is no area outage (check Western Power outage map) |
207 | Insufficient operating frequency stability | Automatic. Contact your installer if persistent |
Class 3: 3xx
Operational status codes
These codes occur during normal operation and generally do not indicate a fault. The inverter manages these conditions automatically. Pay attention if a 3xx code persists for several hours during good sunlight conditions.
| Code | Description | What to do |
|---|---|---|
301 | Overcurrent detected on AC output | Automatic correction. If persistent, contact your installer |
302 | DC voltage too high | Possible PV string design issue. Contact your installer if this appears in normal conditions |
303 | DC-AC board temperature too high | Check the inverter’s ventilation. Clear any debris, spider webs, or vegetation within 300mm of the heatsink fins. Common in Perth summer, especially for inverters in direct afternoon sun |
304 | DC-DC board temperature too high | Same as 303 — check ventilation and airflow |
305 | Internal temperature too high | Inverter is thermally derating (reducing output to protect itself). Check mounting location ventilation. If the inverter is in full afternoon sun, consider installing a shade hood |
306 | Low DC output — insufficient solar input | Normal at dawn, dusk, and during heavy cloud or rain. No action unless it appears during clear midday conditions, which could indicate a panel shading issue or string fault |
307 | DC input voltage too low for feed-in | Same as 306. The PV voltage has dropped below the inverter’s minimum MPPT window. Normal in low-light conditions |
308 | Intermediate circuit voltage too high | If persistent, contact your installer. May indicate a string configuration issue |
311 | DC string polarity reversed | Contact your installer. The DC cables from one or more panel strings may be connected with reversed polarity. This is an installation fault |
312 | Leakage current to earth too high | Contact your installer. Possible insulation fault in the PV array wiring or a panel junction box issue. More common after heavy rain |
313 | Residual current too high — RCMU | Contact your installer. Safety-related. Do not ignore |
314 | Current sensor calibration timeout | Try a restart. If persistent, contact your installer |
Class 4: 4xx
Hardware and software faults
These codes indicate a fault that the inverter cannot resolve on its own. Always try a full restart (AC off → DC off → wait 5 mins → DC on → AC on) first. If the code returns, you need professional service.
| Code | Description | What to do |
|---|---|---|
401 | No communication with power stage set | Restart. If persistent, the inverter needs service. Contact PSW Life Support |
406 | Temperature sensor fault | Restart. If persistent, contact your installer |
407 | Communication fault (internal) | Restart. If persistent, the inverter may need a firmware update or hardware service |
408 | DC input values implausible | Restart. If persistent, contact your installer — possible measurement circuit fault |
412 | Fixed voltage selected instead of MPP tracking | The inverter’s DC input is set to a fixed voltage rather than maximum power point tracking. This is a configuration error. Contact your installer |
416 | No communication with display board | The inverter’s internal display communication has failed. The inverter may still be generating (check Solar.web). Contact your installer |
420 | No communication with Datamanager | Check Wi-Fi / LAN connection. Try restarting the Datamanager or updating firmware. See the Fronius WiFi reconnection guide for step-by-step instructions |
425 | No communication with power stage | Internal communication failure. Restart. If persistent, needs service |
434 | Communication fault with power stage set | Internal. Restart. If persistent, contact your installer |
435 | HID range error | Firmware update required. Contact your installer |
436 | Hardware fault detected | Firmware update required. If persistent after update, contact your installer |
437 | Software fault detected | Restart and check for firmware updates via Solar.web. If persistent, contact your installer |
438 | Error during state code transmission | One-off internal error. If persistent, the inverter needs service |
439 | DC input voltage too low (balance mode) | Restart. If persistent, contact your installer |
442 | Communication between master and power stack failed | Restart. Check internal ribbon cables (licensed electrician only). If persistent, needs service |
443 | DC-DC energy transfer failure | Possible power stack fault. Restart. If persistent, the inverter needs factory service |
445 | Wrong power stack configuration | Internal configuration error. Contact your installer |
447 | Earth fault detected | Contact your installer immediately. Do not restart without inspection. Possible insulation failure in PV array, DC wiring, or within the inverter itself. More common after storms or heavy rain |
450 | Guard fault detected | Safety circuit trip. Contact your installer |
452 | Isolation fault detected | Similar to 447. Contact your installer immediately. Do not ignore — this is a safety-critical fault |
457 | Communication timeout (internal) | Restart. If persistent, contact your installer |
461 | DSP data memory error | Internal processor fault. Contact your installer — the inverter may need a replacement control board |
462 | Timeout in grid monitoring communication | Restart. If persistent, contact your installer |
474 | Power stage set fault | Hardware fault. Contact your installer |
475 | RCMU hardware fault | Safety-critical. Contact your installer immediately. The residual current monitoring unit has a hardware failure |
Class 5: 5xx
Informational warnings
These codes generally do not stop energy production. On SnapINverter models, the code stays on the display until you press the Enter button to acknowledge it. The inverter continues to operate and feed energy into the grid while the code is displayed.
| Code | Description | What to do |
|---|---|---|
501 | Fan measurement circuit fault | The inverter’s fan monitoring has detected an issue. Contact your installer at the next convenient time — not urgent |
502 | Isolation warning on DC side | The inverter has detected reduced insulation resistance between the DC wiring and earth. Common after rain, especially with older junction boxes. Check again in dry weather. If persistent in dry conditions, contact your installer — this can indicate degraded cable insulation, a wet junction box, or a loose MC4 connector |
504 | Duplicate Fronius address in SolarNet | Two inverters on the same SolarNet loop have the same address. Correct the address in the inverter’s Setup menu |
505 | Internal memory (EEPROM) partially reset | If persistent, the inverter needs service |
506 | Internal memory (EEPROM) fault | Contact your installer |
507 | Internal memory data error | Contact your installer |
508 | AC polarity reversed | Contact your installer. The AC wiring connections may be incorrect. This is a safety issue |
509 | No energy fed into the grid over an extended period | The inverter has been connected but not exporting. Check for shading, panel faults, or a tripped DC isolator. If panels are clean and unshaded during daylight, contact your installer |
510 | Fan operational warning | Fan may be running below expected speed. Not urgent — schedule a service inspection |
515 | Safety device (RCMU/AFCI) hardware fault | Contact your installer. Safety device needs replacement |
516 | System monitoring communication lost | Check your internet connection and Datamanager. See the Fronius WiFi reconnection guide |
517 | Power derating due to high temperature | The inverter is reducing output because it is too hot. Improve ventilation around the inverter. In Perth, this is common on 40°C+ days, especially if the inverter is mounted on a west-facing wall |
522 | DC input below operating threshold | Normal at dawn and dusk. The PV voltage is below the inverter’s MPPT window. No action needed |
Class 6 and 7: 6xx / 7xx
Control, configuration and data codes
These codes relate to the inverter’s internal systems: configuration settings, USB operations, firmware updates, SolarNet communication, and data recording. Most require a Fronius Service Partner or your installer to resolve.
| Code | Description | What to do |
|---|---|---|
5xx–6xx range: Firmware update codes | Various codes appear during firmware updates via USB | Follow the update process. If an error occurs during update, do not disconnect the USB. Contact your installer |
567 | Grid voltage-dependent power reduction active | Informational. The inverter is actively reducing output under its volt-watt response curve because grid voltage is elevated. This is normal and compliant behaviour under AS 4777.2. No action needed unless it occurs so frequently that your generation is significantly affected — in which case your installer should review the volt-watt settings and consider a Western Power network assessment |
601 | SolarNet communication error | Check SolarNet cabling between inverters. If persistent, contact your installer |
607 | RCMU sensor calibration fault | Contact your installer. Safety system needs attention |
7xx | Processor status, USB, EEPROM, timer, setup | Most 7xx codes are informational or relate to configuration changes. If any 7xx code persists after restart, contact your installer |
GEN24 state codes
1001–65000
GEN24 inverters (Primo GEN24, Symo GEN24, and the newer Verto series) use a different numbering system. These codes appear as service messages in Fronius Solar.web rather than on a physical display.
| Code | Description | What to do |
|---|---|---|
1001 | Insulation measurement in progress | Normal. After 24 hours of continuous feed-in, the inverter performs a mandatory insulation measurement (required by standards). Feed-in pauses briefly and resumes automatically. No action needed |
1024 | Settings changed — restart required | A configuration change has been applied. The inverter restarts automatically. No action needed |
1030 | WSD (Wired Shut Down) triggered | Three possible causes: (a) triggered alongside another fault — check Solar.web for additional codes, (b) an emergency stop switch or fire brigade switch has been activated, (c) a required bridge is missing from the WSD connector (orange connector on the comms board). For (a), address the other fault first. For (b), check the switch. For (c), contact your installer |
1036 | Grid frequency exceeded limit during reconnection | The inverter detected an out-of-range grid frequency while attempting to reconnect. It will wait until frequency normalises. No action needed |
1112 | Voltage-dependent power reduction active | Equivalent to code 567 on SnapINverters. The inverter is reducing output because grid voltage has exceeded the stored limit. Informational — no action required. If this appears frequently around midday, your installer can review volt-watt response settings |
1117 | Long-term grid voltage limit exceeded | The inverter has detected sustained high grid voltage over an extended period. Try running a high-draw appliance (air-conditioner, pool pump) during peak solar hours to reduce voltage at the inverter terminals. If the issue persists, your installer should request a voltage assessment from Western Power or adjust the inverter’s voltage response settings using a Fronius country setup code |
1175 | Insufficient DC power for feed-in | Normal in low-light conditions (dawn, dusk, heavy cloud, rain, heavy shading). Clears automatically when sufficient sunlight returns |
1196 | Inverter setup values not received | Appears only on first commissioning. Can be ignored |
994–999 | Solar.web communication codes | Relate to data transfer between the inverter and Solar.web. Check your internet connection. If persistent, ensure firmware is up to date |
65000+ | Battery-related state codes | These codes relate to the battery connected to your GEN24 inverter, not the inverter itself. The specific battery (e.g., BYD, LG RESU, Fronius) will be identified in the Solar.web service message. Contact the battery manufacturer directly, or contact PSW Life Support and we will coordinate with the battery supplier on your behalf |
Codes needing professional attention
Most Fronius state codes are either temporary or informational. These specific codes require prompt action from a qualified electrician or Fronius Service Partner. Do not attempt a restart without professional advice if you see any of the following:
- 447 / 452 / 502 (persistent in dry weather): Earth fault or isolation fault. Possible insulation breakdown in DC wiring or panels
- 475 / 607 / 515: RCMU (residual current monitoring unit) hardware fault. This is a safety protection device
- 566: Arc fault detected (Symo Advanced with Arc Guard). Disconnect the system and contact your installer immediately
- 1030 (with red LED, no other codes): WSD triggered without an obvious cause. Contact your installer
- 311 / 508: Polarity reversal (DC or AC). Installation fault that needs correction
PSW customers: For any code in this list, contact PSW Life Support. All other customers should call their original installer.
Fronius LED status indicators
If you cannot read a state code (no display, or a GEN24/Verto model), the LED indicators on the front of the inverter provide a quick status check:
| LED colour | Snap Inverter meaning | GEN24 / Verto meaning |
|---|---|---|
Green (solid) | Normal operation, feeding to grid | Normal operation |
Green (flashing) | Starting up | Starting up |
Orange (solid) | Warning or reduced output | Warning or service message active |
Orange (flashing) | First commissioning in progress | First commissioning / setup wizard |
Red (solid) | Fault — feed-in stopped | Fault — check Solar.web for code |
Red (flashing) | — | Critical fault |
Blue (flashing) | — | Wi-Fi access point active (GEN24/Verto only) |
All LEDs off | No power (AC and DC both disconnected) | No power |
Keeping your Fronius inverter firmware current
Many 4xx state codes can be resolved or prevented by keeping your inverter firmware up to date. Fronius releases firmware updates that improve grid compliance, fix known bugs, and add features.
- SnapINverter firmware updates are performed via USB. Download the firmware file from Fronius Solar.web, copy it to a FAT32-formatted USB drive, insert it into the USB port under the grey cover at the bottom of the inverter, and navigate to Setup → USB → Software Update on the display.
- GEN24 / Verto firmware updates can be initiated remotely through Solar.web under Settings → Components → Data Sources. Your installer can also perform updates via the local web interface.
If your inverter is not connected to the internet, it cannot receive automatic update notifications. PSW recommends connecting your inverter to your home Wi-Fi and enabling service message notifications in Solar.web so you are alerted to both faults and available updates.
Frequently asked questions
My inverter shows a state code briefly at sunrise and sunset. Is this a fault?
No. Codes like 306, 307, 522, and 1175 appear when there is not enough sunlight to meet the inverter’s minimum operating threshold. These are normal at dawn and dusk and clear once irradiance levels rise.
What does code 567 / 1112 mean, and why does it keep appearing around midday?
Your inverter is reducing output because grid voltage at the inverter terminals has exceeded the programmed threshold. This is common in Perth suburbs with high rooftop solar penetration, particularly during spring and autumn when generation is strong and household consumption is low. It is not a fault — the inverter is complying with AS 4777.2 volt-watt response requirements. Your installer can review the voltage settings if this is significantly affecting your generation.
Code 502 appeared after rain. Should I be concerned?
Not necessarily. Moisture ingress into panel junction boxes or MC4 connectors can temporarily reduce insulation resistance. If the code clears when the system dries out, monitor it but no urgent action is needed. If 502 persists in dry conditions, your installer should perform an insulation resistance test on the DC array.
My GEN24 shows a battery-related code (65000+). Who do I call?
Battery faults are managed by the battery manufacturer, not Fronius. However, you can contact PSW Life Support and we will coordinate the warranty or service process with the battery supplier.
I have a code not listed here. What should I do?
Contact PSW Life Support with the code number, your inverter model, and the approximate time the code appeared. We service Fronius inverters across Perth and can diagnose remotely via Solar.web in many cases.
References
- Fronius International — GEN24 support and state codes
- Fronius International — SnapINverter support
- AS 4777.2:2020 — Grid connection of energy systems via inverters (Part 2: Inverter requirements)
- Western Power — Embedded Generation Connection Technical Requirements
This guide is current as at April 2026. Fronius firmware updates may introduce new state codes or modify existing behaviour. PSW customers should contact PSW Life Support for the latest information.
22 replies to “Fronius state codes: what they mean and what to do”
Allen P Savio
Galvo 2.0 after a snowstorm I got error 461 Error in the DSP (digital signal processor) data memory. what should I do? Thanks
Solar Analytica Collaborative
If this status code is displayed all the time contact your solar installer. It is likely that you just need to update your inverter’s software.
John Corder
Does anyone have advice have code state 225 cannot be reset? Changed ground fault fuse twice. Is this inverter outdated? replaced once from the factory. still problems Florida
Jakkie Geldenhuys
Hi, I have a new Fronius Primo inverter that is fed from 26 x 335 watt PV panels. The display keeps showing an error 311. We have had overcloud days since the installation and what I can figure from the error is that the DC input from the PV panels is low. Is this normal that the error keeps showing on the display and that the system doesn’t show any power being generated from the panels. Thanks
Solar Analytica Collaborative
Usually, this fault rectifies itself and it is an indication of “Polarity of DC strings reversed”. If the fault is reoccurring, it is best to contact your installer for a systems check.
Andreas Poth
Same with our inverter? Did you get any response by Fronius?
George T
Hey everyone! Has anyone else experienced a comms card problem with Datamanager 2.0? I’m getting no IP lights and I’ve just thrown in a new comms card…?? Fronius Primo 6.0 – ac coupled with Selectronic SP pro. Cheers.
Hussain Shah
Hi. Recently install a Fronius Titan 2.6 Inverter. But we have an Error code 05. We try find where is the error in installation without result. Can you help us to find resolve?
Rafael Vivas
Hi, my Fronius Primo inverter shows error code 241, what should I do?
Solar Analytica Collaborative
If this fault is reoccurring, contact your installer or a Fronius-trained service technician for a systems check. This status code indicates an Arc Fault has been detected.
Alfonso OGarro
My Fronius inverter (CL 55.5 Delta 3 phase) experiencing error code 530, recurring. Has anyone seen this before and can offer any insight.
Solar Analytica Collaborative
This would indicate a Fan supply voltage exceeding its limits. The Fan is malfunctioning and it would be best to contact a Fronius-trained service technician to resolve this issue.
Henrik
Having the same problem. How did you fix it?
Richard
Can you find a solution for fault 317?. I have the same problem.
Faysal
Hi, I have installed a new 4.2 inverter which is showing that the battery is showing 0’0% and the battery is not loading. Please guide me.
Solar Analytica Collaborative
The DC input voltage from the PV array is too low for feeding energy into the grid. Due to the low level of insolation early in the morning and in the evening, the status codes 306 and 307 are displayed routinely at these times of the day. If these faults occur regularly outside these times, consult with your installer.
Solar Analytica Collaborative
This is an indication of an Insulation fault (connection between solar module and ground). If this fault is a regular occurrence, contact your installer for a systems inspection for any loose wiring.
Solar Analytica Collaborative
Data has not been recorded on the Solar.web over a certain period of time. You can adjust the time span under “Settings” –> “Service messages” –> “Inverter blackout detection”. Check the “DATCOM status” on the display of the inverter under “Setup” –> “DATCOM”. If the status is “Error”, contact your installer.
Solar Analytica Collaborative
This status code notifies the user of a “DC back current detected”. If this fault occurs repeatedly, contact your installer and investigate whether the impedance between PV strings and ground is excessively low.
marc0
I have a Primo Gen24 and it’s happening every day many errors “1117 (Error) / Long-term mains voltage limit exceeded”. This error happens between 11 am to 14 pm when I can see the solar production graph that it’s becoming a zig-zap up-down line. My panels don’t have in that period any shades or something that can justify this. Can you help?
Dietreich Farquharson
Potentially try to operate a high draw appliance (load) during this period such as an air-conditioner to pull the voltage down slightly. If this eliminates the issue, your installer should be able to adjust the voltage settings of the inverter with a code from Fronius. Caution should be exercised though not to exceed your local supply authority’s voltage requirements.
Ryan Rementilla
How to Resolve Error 241
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