A GoodWe inverter error code identifies a protective shutdown, abnormal grid condition, PV-array problem, communication issue, or internal hardware fault. The most useful diagnosis combines the exact alarm text, inverter model, firmware, operating conditions, and whether the event occurs during rain, high heat, battery charging, or utility outages.
Key Facts at a Glance
GoodWe alarm numbers are model and firmware dependent, so the same number can represent different conditions on different series.
Vac Failure means the inverter measured unacceptable AC voltage, while Fac Failure concerns grid frequency.
Isolation Failure usually indicates insufficient resistance between the PV circuit and earth; wet connectors, damaged cables, and module faults are common causes.
PV over-voltage is a DC design fault, not a harmless software warning; do not disconnect live PV connectors.
A single controlled restart can clear a temporary grid event, but repeated resets are unsafe for isolation, arc-fault, burning-smell, or damaged-cable conditions.
GoodWe SolarGo, PV Master, the inverter display, and SEMS Portal can expose different levels of alarm detail.
What GoodWe Fault Codes Actually Mean
GoodWe fault messages fall into two practical groups: external operating faults and inverter-side failures. External faults arise from the utility grid, PV wiring, earthing, temperature, or communication path; inverter-side failures involve relays, memory, sensors, fans, control boards, or power electronics.
A fault code is therefore a symptom, not a complete repair instruction. GoodWe publishes separate user and installation manuals for product families, and those manuals can use different code numbers, wording, LED patterns, and reset procedures. Treat the exact display label and model number as more reliable than a generic internet code list.
The inverter protects itself by checking voltage, frequency, insulation resistance, residual current, temperature, relay state, and internal communications. When a measured value leaves its permitted range, the control system can stop energy conversion and open grid-connected relays. The shutdown may be temporary, latched until a condition clears, or persistent because a component has failed.
Why model matching matters
GoodWe DNS, XS, NS, MS, SDT, SMT, MT, ES, EH, and ET products do not share one universal diagnostic dictionary. “Error 01” may refer to different functions across generations, while a newer hybrid inverter may display a descriptive alarm such as “Overload” or “Isolation Fault” rather than the older numeric format.
| GoodWe family or interface | Common diagnostic display | Typical operating role | Identification detail to record |
|---|---|---|---|
| DNS, XS, NS | LCD, LEDs, local buttons | Single-phase grid-tied | Full model suffix and serial label |
| MS, SDT, SMT, MT | LCD or LED interface | Residential or commercial three-phase | Phase configuration and country code |
| ES, EM, EH | SolarGo or PV Master, LEDs | Battery hybrid | Battery model and state of charge |
| ET, ET Plus, BT | SolarGo, LEDs, app alarms | Three-phase hybrid or battery retrofit | Firmware and backup-load status |
| SEMS-connected units | Plant alarm dashboard | Remote monitoring | Inverter identity, timestamp, alarm history |
How Do You Find a GoodWe Alarm?
Find the alarm locally before attempting a reset, because an app may show a historical event while the inverter display shows a current protective shutdown. Photograph the LCD or LED pattern, record the timestamp, and note whether the inverter is producing power, charging a battery, or offline from the grid.
LCD-equipped GoodWe models commonly expose an active fault through the front-panel navigation keys, although the exact button sequence differs by product manual. Hybrid models usually provide richer information through SolarGo or PV Master over a local Bluetooth connection. SEMS Portal is useful for timestamps and fleet patterns, but it cannot replace local electrical measurements.
| Diagnostic route | What it can reveal | Main limitation | Best evidence to save |
|---|---|---|---|
| Inverter LCD | Numeric fault, operating state, history | Small display and model-specific menus | Full screen photograph |
| Front LEDs | Run, alarm, standby, communication state | Several faults share one red LED | LED pattern and time |
| SolarGo | Parameters, alarms, battery and grid status | Requires local access and compatible model | Alarm detail and parameter screen |
| PV Master | Hybrid settings and battery events | Older or selected hybrid families only | Alarm history and battery values |
| SEMS Portal | Remote timestamps, repeated events, plant trends | Communication loss can hide current state | Plant, device, and alarm exports |
What information should you collect?
Record the inverter model, serial number, exact code or wording, firmware version if visible, grid phase arrangement, battery presence, weather, and the time of day. A fault that appears only at midday heat has a different probability from one that appears immediately after rainfall.
Do not alter country, grid, voltage, battery, or protection settings merely to suppress an alarm. Those settings implement local grid-code and safety requirements, and changing them without an authorised installer can create non-compliance or damage.
GoodWe Inverter Error Codes List and Safe Meaning
The table below maps commonly reported GoodWe labels to their usual diagnostic category. The code column is a cross-reference, not a universal promise. Confirm every number against the manual for the exact inverter model and firmware before replacing hardware.
| Reported code or label | Usual diagnostic meaning | Common cause | Safe first action |
|---|---|---|---|
| Error 01, Error 15, Vac Failure | AC voltage outside permitted range | Utility over-voltage, low voltage, cable voltage rise | Check AC voltage through approved monitoring; contact installer or utility |
| Error 03, Fac Failure | Grid frequency outside limit | Utility disturbance, generator incompatibility, wiring issue | Wait for stable utility supply; escalate if repeated |
| Error 14, Isolation Failure | PV-to-earth insulation below threshold | Wet conduit, damaged cable, cracked module, connector contamination | Keep system off if persistent; installer insulation testing |
| Error 17, PV Over-Voltage | PV DC voltage exceeds inverter input rating | Excessive string Voc, cold-weather design error, wrong stringing | Stop operation using designated isolators; installer inspection |
| Error 19, Over Temperature | Internal temperature exceeds operating limit | Direct sun, blocked ventilation, high ambient temperature, failed fan | Let unit cool; inspect clearance without opening enclosure |
| Error 22, Ground I Fail | Residual or earth-leakage current detected | Insulation damage, moisture, wiring or grounding fault | Do not repeatedly restart; arrange electrical testing |
| Error 23, Utility Loss | Inverter cannot detect the grid | Open breaker, AC isolator, utility outage, loose AC termination | Check only accessible breakers and isolators |
| Error 07 or Error 25, Relay Check | Internal grid relay test failed | Welded relay, failed relay drive, abnormal AC conditions | One authorised restart only; service if persistent |
| Error 16 or Error 20, Fan Failure | Cooling fan speed or feedback abnormal | Debris, seized fan, failed supply, sensor fault | Check external obstruction; technician repair if recurring |
| SPI Failure | Internal processor communication fault | Control-board communication failure or transient boot error | Record code and perform approved restart once |
| EEPROM R/W Failure | Non-volatile memory read/write fault | Memory corruption, board degradation, firmware issue | Preserve settings and contact authorised service |
| AFCI or Arc Fault | Arc signature detected in DC circuit | Loose connector, damaged cable, poor crimp, module fault | Isolate according to manual and call a qualified installer |
Why are the code numbers not perfectly consistent?
GoodWe code lists found online often combine labels from different products. For example, one source may list Error 14 as an insulation problem, while another lists a related alarm under a different number or descriptive label. The underlying category can remain similar even when the numeric identifier changes.
GoodWe installation manuals also distinguish inverter families by input voltage, phase arrangement, protection hardware, and firmware. A generic list is useful for recognizing a category, but the product manual remains the authority for the exact threshold, reset sequence, and terminal instructions.
Which Faults Are Grid-Side Problems?
Vac Failure concerns AC voltage, and Fac Failure concerns AC frequency. Utility Loss indicates that the inverter cannot detect an acceptable grid connection, but the cause may be a local breaker, isolator, cable termination, or wider utility outage.
| Grid alarm category | Typical measurement context | Likely pattern | Escalation trigger |
|---|---|---|---|
| Vac high | Voltage rises during solar production | Appears near midday or at low local demand | Repeats after utility voltage is normal elsewhere |
| Vac low | Voltage sags under load | Starts during heavy household or network demand | Breaker and isolator are on, but alarm persists |
| Fac failure | Frequency leaves configured range | Multiple inverters may alarm together | Utility supply remains unstable |
| Utility Loss | No usable AC reference | Night outage, open isolator, tripped breaker | Other circuits have power but inverter remains disconnected |
| Relay Check | Inverter cannot verify isolation | Follows grid disturbance or relay wear | Returns after one approved restart |
A useful field distinction is simultaneous failure. If several GoodWe inverters at one site report Vac Failure at the same minute, the utility or shared AC infrastructure becomes more likely than simultaneous inverter-board failure. If one unit alone reports the alarm, inspect its AC cable run, termination, breaker, and local voltage rise.
Do not change the grid profile to prevent nuisance alarms. A certified installer or network operator should verify voltage and frequency with suitable equipment under production load.
What Does Isolation Failure Mean?
Isolation Failure means the inverter detected inadequate electrical resistance between the PV circuit and earth, or detected leakage through an unintended path. Moisture inside a connector, damaged cable insulation, a cracked module, conduit water, and roof-mounted metalwork can all produce intermittent readings.
Published online guides often cite approximate limits near 100 kΩ for some single-phase systems and 200 kΩ for some three-phase systems. Those figures are not universal GoodWe specifications. The actual trip value depends on inverter design, array voltage, local protection rules, and measurement conditions.
An installer should isolate strings using the manufacturer’s procedure and use a suitable insulation-resistance tester. Testing positive-to-earth and negative-to-earth on isolated sections can identify whether the fault follows one string, one cable route, or the inverter input. Homeowners should not unplug MC4 connectors under load or open the inverter.
Rain-related faults deserve special attention. A system that starts normally in dry weather but fails after rain often has a connector, cable entry, junction box, module, or conduit-water problem. Repeated resets can energise the defective path again.
What Does PV Over-Voltage Mean?
PV Over-Voltage means the array’s DC voltage exceeded the inverter’s permitted input range, usually because string open-circuit voltage was designed incorrectly or cold conditions raised Voc. The condition can damage the DC input stage and requires installer evaluation, not trial-and-error reconnection.
Cold-weather Voc is the important design variable. A string that appears acceptable under warm operating conditions can exceed the inverter maximum on a cold morning because module voltage rises as temperature falls. Installers calculate maximum string Voc using the module temperature coefficient and the site’s design minimum temperature.
| PV condition | Measurement or design value | Risk | Correct response |
|---|---|---|---|
| Normal operating voltage | Below MPPT upper limit | Expected conversion | Continue monitoring |
| High string Voc | Near or above absolute DC maximum | Input-stage stress | Stop and verify string design |
| Reversed polarity | Positive and negative leads swapped | No production or hardware damage | Qualified polarity test |
| Unequal string current | Parallel strings differ materially | Mismatch or shading | Compare string measurements |
| DC arc suspicion | AFCI or repeated isolation alarm | Fire and shock hazard | Isolate under manual procedure |
The inverter’s DC dial does not make rooftop conductors safe in every condition. PV modules can continue producing voltage in daylight, and stored energy may remain inside the inverter after shutdown.
Can You Reset a GoodWe Inverter Safely?
A GoodWe inverter may be reset once for a temporary grid or boot event, but a reset is inappropriate for persistent isolation faults, PV over-voltage, AFCI alarms, burning smells, water ingress, damaged cables, smoke, or unusual heat. The exact shutdown order must come from the model manual and local electrical rules.
For many grid-tied installations, the general sequence is to switch off the AC supply using the designated breaker or isolator, then switch off the inverter’s DC isolator, wait for the display and indicators to shut down, and restore power in the manufacturer-specified reverse order. Some installations use additional battery or backup-load isolators, so a generic sequence cannot safely cover every GoodWe hybrid system.
- Photograph the alarm and record the time.
- Stop if there is smoke, arcing, heat damage, water entry, or a burning odour.
- Use only labelled external isolators that you are authorised to operate.
- Wait for the manual’s specified discharge period, often several minutes.
- Restore AC, DC, battery, and backup circuits only in the documented order.
- Observe the startup self-test for several minutes.
- Escalate if the alarm returns or production does not resume.
GoodWe manuals commonly state, “Do not open the inverter cover,” because hazardous voltages can remain inside the enclosure. That instruction applies even after external switches are off. Qualified technicians use rated test equipment and follow lockout procedures.
Why Does a GoodWe Inverter Shut Down in Heat?
Over Temperature occurs when the inverter’s internal thermal measurement exceeds its operating limit, often during high irradiance and hot ambient conditions. Direct afternoon sun, restricted airflow, dust, insects, undersized ventilation clearance, and a failing fan can all reduce heat rejection.
Do not assume that cleaning alone solves a recurring thermal alarm. Compare the alarm time with ambient temperature, output power, and whether the enclosure is shaded. An inverter that alarms at modest output on a mild day has a different fault profile from one that derates only during extreme summer production.
| Thermal symptom | Likely cause | Homeowner check | Technician check |
|---|---|---|---|
| Alarm at peak afternoon | Ambient heat or direct sun | Confirm clear external airflow | Thermal inspection and output comparison |
| Fan Failure message | Fan obstruction or failed motor | Look for webs and debris externally | Fan voltage, speed feedback, replacement |
| Gradual power reduction | Thermal derating | Check whether output returns after cooling | Heat sink, sensors, firmware, load profile |
| Alarm after cleaning | Internal or sensor fault | Do not spray liquid into vents | Sensor and board diagnostics |
| Nighttime temperature alarm | Sensor or control fault | Record timestamp and conditions | Temperature sensor and control board test |
Maintain the clearance stated by the installation manual. A universal 300 mm envelope is not a substitute for the model’s installation requirements or local fire rules.
How Can You Tell an Alarm From a Monitoring Failure?
A monitoring failure means SEMS cannot receive data; it does not automatically mean the inverter has stopped converting energy. Check the inverter LEDs, local display, AC output, and SolarGo connection before treating an offline plant as an electrical fault.
Wi-Fi configuration can cause a communication-only problem. Many GoodWe communication modules support 2.4 GHz Wi-Fi, while a router’s band steering, changed password, weak signal, or replaced network can prevent reconnection. A working inverter can therefore appear offline in SEMS.
| Observation | More likely explanation | Next check |
|---|---|---|
| Green run indicator, SEMS offline | Internet or Wi-Fi issue | Local app and router connection |
| Red alarm indicator, SEMS online | Electrical or hardware fault | Read current inverter alarm |
| All site units offline | Router, gateway, or internet outage | Network equipment and SEMS status |
| One unit offline | Local Wi-Fi, communication cable, or datalogger | Device-level connection |
| No display and no LEDs | AC/DC supply, shutdown, or hardware issue | Check labelled isolators, then installer |
Do not change inverter protection parameters to repair Wi-Fi. Network troubleshooting and electrical troubleshooting are separate workstreams.
Which GoodWe Faults Need an Installer Immediately?
An installer should handle PV over-voltage, persistent Isolation Failure, AFCI, Ground I Fail, damaged DC connectors, melted wiring, water ingress, repeated Relay Check Failure, and any internal SPI or EEPROM alarm. These conditions involve hazardous DC energy, insulation testing, relay verification, firmware, or board-level diagnosis.
| Fault condition | Homeowner action | Installer action | Typical urgency |
|---|---|---|---|
| Smoke, arc, melted connector | Stay clear and isolate only if safe | Emergency electrical inspection | Immediate |
| PV over-voltage | Do not restart or unplug DC leads | Verify string Voc and design | Same day |
| Isolation Failure after rain | Avoid repeated resets | Insulation and string testing | Prompt |
| Vac Failure recurring | Record times and voltage evidence | AC voltage-rise test and utility escalation | Within days |
| EEPROM or SPI alarm | Record code and serial number | Firmware and control-board diagnosis | Service appointment |
| Fan Failure | Clear external debris only | Fan, sensor, and thermal test | Prompt if overheating |
A technician may need a True RMS meter for AC voltage and frequency, an insulation tester suited to the system, clamp measurements, polarity checks, and manufacturer-specific software. Those tests are not interchangeable. An insulation tester applied incorrectly can damage connected electronics.
How Much Does GoodWe Inverter Repair Cost?
Typical out-of-warranty costs range from about $150-$300 for a diagnostic visit, $80-$150 for an external fan replacement, and $450-$900 for a main control-board replacement, excluding regional labour, access equipment, shipping, taxes, and battery-system complexity.
These are practitioner estimates, not fixed GoodWe prices. Warranty status, installer responsibility, roof access, travel distance, and whether the utility must attend can change the total substantially.
| Service item | Typical cost range | Typical time | Cost driver |
|---|---|---|---|
| Remote diagnosis | $0-$150 | 15-60 minutes | Warranty and installer policy |
| On-site electrical diagnosis | $150-$300 | 1-3 hours | Travel, testing, access |
| Cooling fan replacement | $80-$150 for part | 1-2 hours | Model and labour rate |
| Control-board replacement | $450-$900 for part and service | 2-6 hours | Board availability and programming |
| Full inverter replacement | $1,000-$3,500+ | 2-8 hours | Capacity, battery integration, labour |
Before approving a paid repair, ask whether the inverter is within its product warranty, whether the replacement board is new or refurbished, and whether firmware or commissioning is included. A repair with a long lead time may be less practical than a current compatible replacement, especially when the inverter is older and out of warranty.
Repair, Warranty, or Replacement?
Warranty service is usually the first choice for a persistent internal alarm, provided the installer can document the fault and the installation meets warranty conditions. Replacement becomes more attractive when a board is unavailable, repair cost approaches the price of a compatible new unit, or the system requires a discontinued communication platform.
Prepare the serial number, purchase or commissioning date, fault photographs, alarm history, weather pattern, and any previous service report. Do not erase evidence by repeatedly resetting the unit before the installer records the event.
| Decision factor | Repair is usually preferable | Replacement is usually preferable |
|---|---|---|
| Warranty | Confirmed active warranty | Warranty expired |
| Fault type | Fan or replaceable external part | Repeated board or power-stage failure |
| Age | Modern supported model | Older discontinued model |
| Battery system | Existing compatibility is valuable | New system offers required backup features |
| Total cost | Below roughly 40%-50% of replacement | Near or above replacement cost |
| Lead time | Part available within days | Board lead time extends for weeks |
The cheapest immediate option is not always the lowest lifetime cost. A replacement can require new commissioning, export-control settings, monitoring setup, and battery compatibility checks.
What Should You Do When the Fault Appears Only Sometimes?
Intermittent GoodWe alarms should be diagnosed by pattern rather than by the last code displayed. Rain, cold mornings, midday voltage rise, high battery current, and simultaneous site-wide events each point toward different causes.
| Trigger pattern | Highest-probability area | Evidence to collect | Avoid |
|---|---|---|---|
| Begins after rain | PV insulation or connector | Rainfall, alarm time, string history | Repeated forced restarts |
| Appears at midday | AC voltage rise or heat | Output, AC voltage, temperature | Changing grid limits |
| Appears at dawn | Cold-weather Voc or startup condition | Minimum temperature, string design | Disconnecting live DC |
| Appears during battery charge | Battery, CAN link, temperature, limits | State of charge and battery alarm | Altering battery settings |
| All inverters alarm together | Utility or shared switchgear | Common timestamp and grid event | Replacing all inverters first |
One practitioner rule is especially useful: correlate the alarm with irradiance and temperature before blaming the inverter. A code that follows weather or production load often identifies the operating condition more accurately than a one-time bench test.
Common Mistakes and Better Recovery
Repeatedly resetting an isolation alarm
A reset does not dry a wet connector or repair damaged insulation. Keep the system isolated according to the manufacturer’s procedure and arrange string-level testing.
Disconnecting MC4 connectors in daylight
Live PV connectors can create a DC arc that burns contacts and starts a fire. Use the designated isolators and qualified procedures instead.
Treating every red LED as a failed inverter
A red alarm can represent a temporary grid event, insulation issue, fan fault, or internal error. Read the exact code before authorising a board replacement.
Changing grid parameters to stop Vac or Fac alarms
Protection limits exist to satisfy the applicable grid code. Only an authorised installer or utility representative should change them.
Spraying water into cooling openings
Liquid can reach electronics and worsen the fault. Clean only accessible external surfaces with the inverter de-energised and follow the manual’s maintenance instructions.
GoodWe Error Code FAQ
What is the most common GoodWe inverter error?
Grid-related Vac Failure, Utility Loss, and insulation-related alarms are common categories reported by installers, but no manufacturer-wide ranking applies to every model or country. Frequency depends on local network voltage, climate, installation quality, inverter age, and whether the system includes batteries.
How long does a GoodWe inverter take to reconnect?
A GoodWe inverter normally waits through its configured grid reconnection and self-test period after acceptable voltage and frequency return. The practical time can range from several minutes to longer, depending on model, grid code, and the fault history. Do not interpret a short delay as proof of failure.
Why is my GoodWe inverter offline at night?
Many solar inverters stop producing at night, but SEMS may still report communication if the datalogger and auxiliary supply remain active. If the portal shows offline only overnight, compare the local LEDs, monitoring schedule, battery operation, and router uptime before investigating electrical faults.
Can rain cause a GoodWe isolation fault?
Rain can expose insulation weaknesses in PV connectors, conduit, junction boxes, module cables, and cracked modules. If Isolation Failure appears after wet weather and clears when dry, the pattern strongly supports moisture ingress, but an installer must confirm the defective section with proper insulation testing.
Should I turn off my GoodWe inverter during a fault?
Turn the inverter off only when the model instructions and labelled isolators support that action, or when an installer directs you. Smoke, arcing, exposed conductors, water ingress, burning odour, PV over-voltage, and AFCI conditions require immediate professional escalation rather than repeated switching.
Where can I find the exact manual for my GoodWe model?
Use the model and suffix from the inverter rating label, then obtain the corresponding GoodWe user manual or installation manual from GoodWe’s official support or download pages. Manuals for DNS, SDT, ET, EH, and other families should not be substituted for one another.
The Bottom Line
The most reliable GoodWe inverter error codes list begins with the exact model, alarm wording, firmware, and event conditions. Use generic code tables to identify a category, then confirm the meaning in the official manual. Grid alarms may clear when utility conditions recover, while isolation, PV over-voltage, AFCI, ground-current, and internal board alarms require qualified diagnosis. One controlled restart may clear a transient event, but repeated resets and live DC disconnection create avoidable electrical risk. Record the evidence, preserve warranty information, and contact the installer when the alarm returns.