Growatt Error Codes
Growatt's dual numbered-and-named error scheme decoded — what each Error and Warning means, and whether it needs an installer.
- Manufacturer
- Growatt
- Codes documented
- 21
- Source
- Growatt docs & field references
- Scope
- Reference only
An independent reference compiled by Solar Analytica from Growatt documentation and field sources. Growatt shows faults two ways depending on model and firmware: newer inverters display a numbered Error code (1xx system, 2xx PV/DC, 3xx AC grid, 4xx hardware), while many single-phase units show a named message like “PV Isolation Low.” Where a fault has both, we list them together — and both are searchable. Safety note: never open the inverter or work on wiring under load; for a high-DC-voltage fault, switch off the DC isolator first, and leave internal repairs to a licensed installer.
- 21 Growatt fault and alarm codes, documented in plain English.
- Compiled from manufacturer documentation — independent and not affiliated with Growatt.
- Codes involving DC/AC isolators, wiring or opening the unit are licensed-electrician work — when in doubt, call your installer.
21 of 21 codes
- 100
Reference voltage fault
An internal 2.5 V reference-voltage fault — a hardware-level problem on the control board.
What to do
Restart the inverter (turn off AC, then the DC isolator, wait 5 minutes, and reverse). If it returns, the board needs servicing — contact your installer or Growatt.
- 101
Communication fault
Loss of data between the main (DSP) and slave processors inside the inverter.
What to do
Perform a hard reset: DC off → AC off → wait 5 minutes → restart. If it persists, the control board needs professional repair.
- 102
Master/slave data mismatch
The data received by the master and slave processors disagree, often triggered by an unstable grid.
What to do
Restart the inverter and check whether the grid is stable. If it recurs, contact your installer or Growatt.
- 116
EEPROM fault
A fault in the inverter's internal (EEPROM) memory.
What to do
Restart the inverter. If the fault remains, it needs servicing — contact your installer or Growatt.
- 117
Relay fault
The internal grid relay is stuck (contacts welded) or its coil has failed.
What to do
Restart once; if it returns, the relay or power board must be replaced by a technician.
- 118
Initialisation / model fault
The inverter failed to initialise correctly (model/config fault).
What to do
Restart the inverter. If it persists, contact your installer or Growatt.
- 119
GFCI device damage
The internal residual-current (GFCI/RCD) sensor is damaged.
What to do
Restart once. If it remains, the safety sensor is compromised — arrange repair promptly; don't ignore it.
- 120
HCT (current sensor) fault
The Hall-effect current sensor is reading inaccurately or has failed.
What to do
Restart the inverter. If it persists, the sensor on the mainboard needs replacement by a technician.
- 121
Slave processor communication loss
The master processor cannot receive data from the slave processor.
What to do
Restart the inverter. If the error persists, contact your installer or Growatt.
- 122
Bus voltage fault
The internal DC bus voltage is out of its normal range.
What to do
Restart the inverter. If it recurs, contact your installer or Growatt.
- 201 · Residual I High
Residual (leakage) current high
Earth-leakage current from the PV system has exceeded the safety threshold.
What to do
Restart once. If it recurs, an installer should inspect the DC cabling for damaged or stripped insulation (including rodent damage) and check the array's isolation.
- 202 · PV Voltage High
PV input voltage too high
The PV string voltage exceeds the inverter's maximum input rating.
What to do
Turn off the DC isolator. The string most likely has too many panels in series — your installer must re-check the string sizing against the inverter's maximum voltage.
- 203 · PV Isolation Low
PV isolation (insulation) low
Low insulation resistance between the array and ground — most common in rain or high humidity.
What to do
If it clears once things dry out, moisture is getting in. Have an installer inspect the MC4 connectors for water ingress or corrosion, and check the array and inverter grounding.
- 205 · PV Boost Broken
PV boost circuit broken
The DC-DC boost converter circuit is damaged.
What to do
This is a board-level fault — contact your installer, the warranty centre, or Growatt for repair.
- 300 · AC V Outrange
Grid voltage out of range
The grid voltage is too high (often above ~255–270 V) or too low for the inverter to stay connected.
What to do
Usually clears when the grid returns to range. If it's frequent, your network voltage may be high — contact your installer or network operator; protection/volt-watt settings may need review (with the operator's consent).
- 302 · No AC Connection
No AC connection
No grid is connected — a grid outage, an open main switch, or a missing phase / open neutral.
What to do
Check the AC main switch / supply main switch and confirm the grid is on. If the grid is present and it persists, have an installer check the AC wiring and connections.
- 303 · PE Abnormal
PE (earth) abnormal
A grounding fault — the voltage between neutral and protective earth (PE) is too high.
What to do
Have a licensed electrician inspect the earth connection and measure ground resistance. Don't work on the earthing yourself.
- 304 · AC F Outrange
Grid frequency out of range
The grid frequency is outside the permitted range (deviating from 50/60 Hz).
What to do
Usually a grid event that self-clears — common when running off a backup generator. If it's frequent on mains power, contact your network operator.
- 408 · Over Temperature
Over temperature
The inverter's internal temperature has exceeded its limit.
What to do
Check the cooling fans and air vents for blockage, ensure good airflow, and keep the unit out of direct sun and confined spaces. If it persists in normal conditions, contact your installer.
- Output High DCI
Output DC injection high
The DC component of the inverter's AC output current is too high.
What to do
Restart the inverter. If the warning persists, contact your installer or Growatt.
- Auto Test Failed
Auto-test failed
The inverter's self-test (a grid-protection test required in some regions) did not pass.
What to do
Restart and let the test re-run. If it fails again, contact your installer — the grid-protection settings or a hardware check may be needed.
Frequently asked
- Where do these Growatt fault codes come from?
- We compile them from publicly available Growatt inverter documentation and field references, then rewrite each entry in plain English. Solar Analytica is independent and not affiliated with Growatt.
- Can I clear these faults myself?
- Some clear automatically once conditions return to normal. Anything involving DC isolators, AC switches, wiring or opening the unit is licensed-electrician work — if in doubt, contact your installer rather than working on a live system.
- My exact code isn't listed — why not?
- Firmware and model variants differ, and manufacturers occasionally revise their codes. We document the most common ones; if yours isn't here, check your inverter's manual or ask your installer.
- How current is this reference?
- Last reviewed June 2026. We revise it when the underlying manufacturer documentation changes.
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