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Growatt Error Codes

Expert reference guide covering all Growatt inverter diagnostic codes with comprehensive troubleshooting procedures and professional repair guidance

Quickly identify problems with your Growatt solar system and learn the correct response procedures

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Growatt Inverter Models

Growatt produces an extensive lineup of premium inverter systems for residential and commercial solar installations. The MIN series represents compact single-phase inverter technology, while MOD series models provide modular solutions with battery integration. MAX series offers high-power three-phase inverters for larger installations. These diagnostic codes are applicable to the majority of Growatt inverter systems sold in the United States. Error indicators typically manifest as numeric error codes on the inverter display, LED status indicators, and status messages in the monitoring portal.

How to Read Error Codes

• Check inverter display for error code numbers (e.g., 101, 102, 202, 203, 300)
• Review LED status indicators on inverter
• Check monitoring portal for system status messages
• Note error code format and any additional information
• Consult Growatt documentation for your specific model

Growatt Product Series

• MIN Series - Compact single-phase inverters
• MOD Series - Modular inverters with battery integration
• MAX Series - High-power three-phase inverters
• ARK Series - Battery storage solutions
• Monitoring - System monitoring and communication

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Understanding Diagnostic Codes

Growatt inverter systems incorporate sophisticated diagnostic capabilities that automatically detect operational issues. When a problem is identified, the system communicates through numeric error codes displayed on the inverter, LED status indicators, and status messages in the monitoring portal. This intelligent diagnostic framework enables rapid problem identification and helps determine the appropriate response. All Growatt inverter series (MIN, MOD, MAX, ARK) utilize continuous performance monitoring with real-time error detection. Error codes are typically three-digit numbers (e.g., 101, 102, 202, 203, 300, 302, 303, 304, 305, 411, 423, 424, 425, 426, 427, 428) that indicate specific system conditions or faults. Always reference your specific model's installation manual for precise code definitions.

Communication and System Errors

Problems with communication and internal system components.

Code	Meaning	Possible Causes	Solutions
101	Communication Error - Inverter cannot establish connection to other devices or systems	•Communication wire break •Data logger offline •Network issue •Communication protocol error •Device not responding	Restart the inverter Check communication wiring connections Verify data logger is online Check network connection If error persists, contact Growatt support
102	Permanent Error - Permanent fault, possibly caused by grid problems	•Grid problems •Internal fault •System error •Hardware failure	Restart the inverter If error occurs again or persists after restart, check the grid Verify grid voltage and frequency Check for grid anomalies If problem persists, contact Growatt support
116	EEPROM Error - Error in non-volatile memory of inverter	•EEPROM memory fault •Memory corruption •Internal memory error •Data storage failure	Contact Growatt support This requires professional diagnosis EEPROM may need to be reprogrammed or replaced
117	Relay Error - Problem with internal relay of inverter	•Faulty relay •Relay stuck •Relay circuit failure •Internal relay malfunction	Contact Growatt support This requires professional diagnosis Relay may need to be replaced
118	Initialization Error - Inverter could not be properly initialized	•Startup failure •Initialization sequence error •System boot failure •Configuration error	Contact Growatt support This requires professional diagnosis System may need to be reset or reconfigured
119	GFCI Error - Error in ground fault circuit interrupter	•GFCI fault •Ground fault detection error •GFCI circuit failure •Safety system error	Contact Growatt support This is a safety-related error requiring professional diagnosis Do not attempt to bypass GFCI
120	HCT Error - Problem with high current transformer	•HCT fault •Transformer failure •Current sensing error •Hardware malfunction	Contact Growatt support This requires professional diagnosis Transformer may need to be replaced
121	Main CPU Error - Error in main control unit of inverter	•CPU fault •Control board issue •Processor error •Internal control failure	Restart the inverter If error persists, contact Growatt support This may require control board replacement
122	Bus Voltage Error - Irregularities in bus voltage of inverter	•Bus voltage fault •DC bus problem •Voltage regulation error •Internal power stage issue	Contact Growatt support This requires professional diagnosis Internal power stage may need repair

DC Voltage and Isolation Errors

Problems with DC input voltage and electrical isolation.

Code	Meaning	Possible Causes	Solutions
202	DC Input Overvoltage - DC input voltage exceeds maximum allowable value	•Too many modules in series •String voltage exceeds maximum •Cold weather voltage rise •Incorrect string configuration •Module mismatch	Immediately disconnect DC switch Check voltage of each string with multimeter If string voltage is less than 550V, contact Growatt support Verify number of modules per string matches inverter specifications Account for cold weather voltage rise Reduce number of modules if necessary Contact certified installer to verify string configuration
203	PV Isolation Low - Low insulation values in PV system	•Damaged cables or modules •Water ingress in junction boxes •Damaged DC wiring insulation •Ground fault in PV array •Moisture in connections	Check if PV panel housing is properly grounded Inspect all PV module connections and junction boxes Check DC wiring for damage or water ingress Test isolation resistance with megohmmeter If error message persists, contact Growatt support This is a serious safety condition requiring professional diagnosis
411	PV Voltage Low - PV voltage is too low	•Too few modules in series •Shading on panels •Faulty modules •DC wiring losses •Poor contact in connections •String configuration error	Check PV connections for poor contact problems Verify PV voltage is within required range If everything on PV side is OK, try restart in this order for MIN-XH/MOD-XH+ARK XH system: Turn off battery → turn off DC switch of inverter → turn off AC side Then start battery → turn on DC switch → turn on AC side Inspect panels for shading Check for faulty modules in string If error persists, contact Growatt support

AC Grid Connection Errors

Problems with AC grid voltage, frequency, and connection.

Code	Meaning	Possible Causes	Solutions
300	AC Voltage Out of Range - Grid voltage outside allowable range	•Utility grid voltage too high •Utility grid voltage too low •Grid voltage fluctuations •Grid instability •Voltage regulation issue	Check grid voltage Verify voltage is within allowable limits Do not attempt to override safety shutdown If error message persists even though grid voltage is in acceptable range, contact Growatt support Wait for grid voltage to return to normal range System will automatically reconnect when voltage stabilizes
302	No AC Connection - Inverter detects no connection to AC grid	•AC wiring disconnected •Main breaker tripped •AC switch off •Grid connection failure •Wiring issue	Check AC wiring after shutdown Verify AC connections are secure Check main breaker for system Ensure AC switch is turned on If error message persists, contact Growatt support
303	PE Abnormal - Abnormal voltage between neutral and PE (ground)	•PE wiring issue •Neutral-ground fault •Grounding problem •AC wiring error	Check PE to ensure PE wire is properly contacted Check neutral and PE voltage Check AC wiring Verify proper grounding Restart inverter If error still exists, contact Growatt support
304	AC Frequency Out of Range - Grid frequency outside allowable range	•Grid frequency too high •Grid frequency too low •Grid instability •Frequency fluctuations •Grid synchronization issue	Check AC wiring, especially neutral and ground Check if grid frequency meets local requirements Restart inverter Verify frequency is within allowable limits If error still exists, contact Growatt support Contact utility company if frequency is consistently out of range
305	Overload Error - Output load of inverter exceeds allowable range	•Excessive load •Load exceeds inverter capacity •Overcurrent condition •Load imbalance	Check if output load exceeds range If load is too high, reduce it Verify load does not exceed inverter specifications Check for load imbalances If error message persists, contact Growatt support

Internal Inverter Errors

Problems with inverter internal systems and power stages.

Code	Meaning	Possible Causes	Solutions
423	AC PWM Bypass Protection - Protection triggered due to problem in AC PWM bypass	•AC PWM bypass fault •Bypass circuit error •Internal power stage issue •Hardware malfunction	Restart the inverter If error message still persists, inform Growatt customer service This may require professional diagnosis
424	INV Current Fault - Error detected in inverter current	•Inverter current sensing error •Current measurement fault •Power stage issue •Hardware malfunction	Restart the inverter If error message still persists, inform Growatt customer service This may require professional diagnosis
425	AFCI Self-Test Error - Error in AFCI self-test	•AFCI self-test failure •Arc fault detection error •AFCI circuit fault •Safety system error	Restart the inverter If error message still persists, inform Growatt customer service This is a safety-related error requiring professional diagnosis
426	PV Current Sensing Fault - Error in PV current sensing	•PV current sensor fault •Current measurement error •Sensor wiring issue •Hardware malfunction	Restart the inverter Check PV current sensors If error message still persists, inform Growatt customer service
427	AC Current Sensing Fault - Error in AC current sensing	•AC current sensor fault •Current measurement error •Sensor wiring issue •Hardware malfunction	Restart the inverter Check AC current sensors If error message still persists, inform Growatt customer service
428	BOOST Converter Short Circuit - Short circuit in BOOST converter	•BOOST converter failure •Short circuit in power stage •Hardware malfunction •Component failure	Contact Growatt support immediately This is a serious hardware fault Do not attempt to restart Professional diagnosis and repair required

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Critical Safety Notice

Do not attempt DIY repairs on your Growatt solar system. The majority of diagnostic codes relate to high-voltage DC and AC electrical systems, grid connection safety mechanisms, or critical safety features. Specific codes requiring immediate professional intervention include: 203 (PV Isolation Low), 428 (BOOST Converter Short Circuit), and 119 (GFCI Error). Upon encountering these codes, immediately shut down the system if safe to do so and contact a certified Growatt installer without delay.

Professional service is mandatory—contact a licensed solar installer or reach out to Growatt technical support for expert assistance.

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Maintenance Guidelines

Scheduled Service Requirements

✓Professional inspection and service annually by certified Growatt installer
✓Monthly visual inspection of solar panels for damage or soiling
✓Clean panels quarterly or as needed based on local conditions
✓Monitor system performance daily through monitoring portal
✓Check inverter status and LED indicators monthly
✓Verify data logger is online and communicating

Proactive Maintenance Strategies

✓Keep panels clean to maximize energy production
✓Trim trees and vegetation to prevent shading
✓Ensure adequate ventilation around inverter
✓Monitor production trends for early problem detection
✓Keep firmware updated for latest features and fixes
✓Review system alerts and error codes promptly

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Frequently Asked Questions

What does error code 101 (Communication Error) mean?

Error code 101 indicates that the inverter cannot establish connection to other devices or systems. Restart the inverter, check communication wiring connections, verify data logger is online, and check network connection. If the error persists, contact Growatt support.

What does error code 202 (DC Input Overvoltage) mean?

Error code 202 indicates that the DC input voltage exceeds the maximum allowable value. Immediately disconnect the DC switch, check voltage of each string with a multimeter, verify number of modules per string matches inverter specifications, and account for cold weather voltage rise. If string voltage is less than 550V, contact Growatt support.

What should I do if I see error code 203 (PV Isolation Low)?

Error code 203 indicates low insulation values in the PV system. Check if PV panel housing is properly grounded, inspect all PV module connections and junction boxes, check DC wiring for damage or water ingress, and test isolation resistance. This is a serious safety condition requiring professional diagnosis. If the error message persists, contact Growatt support.

What does error code 300 (AC Voltage Out of Range) mean?

Error code 300 indicates that the grid voltage is outside the allowable range. Check grid voltage and verify it is within allowable limits. Do not attempt to override the safety shutdown. If the error message persists even though grid voltage is in acceptable range, contact Growatt support. Wait for grid voltage to return to normal range.

What should I do if my inverter shows error code 411 (PV Voltage Low)?

Error code 411 indicates that the PV voltage is too low. Check PV connections for poor contact problems and verify PV voltage is within required range. If everything on PV side is OK, try restart in this order for MIN-XH/MOD-XH+ARK XH system: Turn off battery → turn off DC switch of inverter → turn off AC side. Then start battery → turn on DC switch → turn on AC side. If error persists, contact Growatt support.

Can I repair my Growatt system myself?

High-voltage DC and AC electrical work must exclusively be performed by licensed professionals to ensure safety compliance. Homeowners can safely perform basic tasks like cleaning panels and monitoring the system portal, but all technical repairs require certified Growatt installers. Unauthorized work on electrical systems poses extreme danger and violates building codes.

What does error code 428 (BOOST Converter Short Circuit) mean?

Error code 428 indicates a short circuit in the BOOST converter. Contact Growatt support immediately. This is a serious hardware fault. Do not attempt to restart. Professional diagnosis and repair is required.

How often should I clean my solar panels?

Solar panels should be cleaned quarterly or as needed based on local conditions. Panels in dusty areas or areas with heavy pollen may need more frequent cleaning. Keep panels clean to maximize energy production. Inspect panels monthly for damage or excessive soiling that may require immediate cleaning.

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Summary

Proper interpretation of diagnostic codes is essential for effective Growatt solar system troubleshooting. This comprehensive reference enables quick problem identification and guides appropriate response actions. Growatt systems utilize numeric error codes displayed on inverter displays, LED status indicators, and status messages in the monitoring portal to indicate specific sensor and system malfunctions. MIN, MOD, MAX, and ARK series inverters provide diagnostic information through error codes and monitoring systems for convenient diagnosis.

⚠️Complex diagnostic situations, especially those involving high-voltage DC and AC electrical systems and grid connection safety, require immediate professional evaluation. Critical codes demanding urgent response include: 203 (PV Isolation Low), 428 (BOOST Converter Short Circuit), and 119 (GFCI Error). These indicators represent serious safety hazards requiring certified Growatt installer response. Adherence to scheduled maintenance protocols and immediate attention to diagnostic codes extends equipment service life and minimizes long-term operational costs. Note that error code formats may vary by model and firmware version—always consult your specific unit's installation and service manual for precise interpretations.