Growatt MTL Solar InverterThe Growatt MTL solar inverter is manufactured in Shenzhen, China. 

If your Growatt MTL inverter is displaying a fault or error message on the screen we highly recommend you take action as quickly as possible, as when a Growatt MTL inverter has a fault it will not be producing any power.

To help you take action we have put together a list of Growatt MTL fault messages and possible actions to take from the Growatt MTL Solar Inverter user manual.

Should any problems arise on your Growatt MTL solar inverter, the LED on the front panel will be red and the LCD displays the relevant information. If you decide to follow the recommended actions below, please note that safety measures should be observed to avoid any risk of injury. If unsure we highly recommend you seek assistance from a qualified solar electrician.

Need service for your solar power system?



Possible Action

SYSTEM FAULTGround I Fault1. The ground current is too high. 

2. Unplug the inputs from the PV generator and check the peripheral AC system.

3. After the cause is cleared, re-plug the PV panel and check PV-Inverter status.

4. If the problem persists please call service.

Isolation Fault1. Check the impedance is between PV (+) & PV (-) and the PV-Inverter is earthed. The impedance must be greater than 8M. 

2. If the problem persists please call service.

No Utility1. Grid is not connected. 

2. Check grid connection cables.

3. Check grid usability.

PV Over Voltage1. Check the open PV voltage; see if it is greater than or too close to 600VDC. 

2. If PV voltage is less than 600VDC, and the problem still occurs, please call local service.

Consistent Fault1. Disconnect PV (+) or PV (-) from the input, restart the PV-Inverter. 

2. If it does not work, call service.
> If there is no display on the panel, please check PV-input connections. If the voltage is higher than 150V, call your local service.

> During periods of little or no sunlight, the PV-Inverter may continuously start up and shut down. This is due to insufficient power generated to operate the control circuits.

Here are some more fault messages that you may see on the Growatt MTL front panel display.

System FaultAuto Test FailedAuto test do not pass
No AC ConnectionNo utility; no grid connect
PV Isolation LowInsulation problem
Residual HighGFCI Fault
Output High DCIOutput current DC, offset too high
PV Voltage HighPV panel voltage too high
AC V OutrangeGrid voltage out of range
AC F OutrangeGrid frequency out of range
Inverter FaultError: 1002.5 V Reference Voltage Fault
Error: 101Communication Fault
Error: 102Consistent Fault
Error: 116EEPROM Fault
Error: 117Relay Fault
Error: 118Init Model Fault
Error: 119GFCI Device Damage
Error: 120HCT Fault
Error: 121Communication Fault
Error: 122Bus Voltage Fault

Need service for your solar power system?

The full information is available in the Growatt MTL solar inverter manual’s troubleshooting section.

If following the steps above does not fix the issue and your Growatt MTL inverter is still within the warranty period you can contact the equipment installer or supplier.  If your inverter is outside the warranty period we suggest that you contact a professional solar power expert. If you’re on the Gold Coast or Brisbane area contact Gold Coast Power Solutions here and we will be in touch to provide you with further assistance.

Need a quality solar inverter? We deliver Australia wide
Got A Question About Solar Power? Click Here For Answers!

Learn more about solar power battery storage here