Hoymiles error codes explained

What 29 Hoymiles inverter fault and error codes mean, in plain English, with safe checks you can do and when to call a licensed electrician.

Safety first: never open the switchboard, remove covers, or pull apart or disconnect the inverter, batteries, isolators or wiring. Only use the switches and buttons described here. Anything else must be done by a licensed electrician. Call 1300 209 503 or book a service request.

Guide only. This information is a general guide taken from manufacturer documentation. All electrical work must be performed by a licensed electrician. Never open your inverter, battery or switchboard. If you see smoke, smell burning or see damage, keep clear and call 000.

Code	Message & meaning	Model	Type
121Warning	Over temperature protection Over temperature protection What you can do Check from a safe distance that the inverter is shaded, has clear space around it and that nothing is blocking the vents It usually recovers once it cools down If it repeats often or you can hear a noisy/failed fan, call your installer HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
125Warning	Grid configuration parameter error Grid configuration parameter error What you can do Check the monitoring app for the alarm and whether export/consumption readings look wrong Restart your home router if the meter talks over Wi-Fi or LAN Call your installer - meter and CT wiring is inside the switchboard and must be checked by a licensed electrician HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
126Warning	Software error code 126 Software error code 126 What you can do Make sure the system is online so it can receive updates Restart the system once using the owner steps in your manual If the alarm stays, call your installer - settings and firmware must be fixed by them or the manufacturer HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
127Warning	Firmware error Firmware error What you can do Make sure the system is online so it can receive updates Restart the system once using the owner steps in your manual If the alarm stays, call your installer - settings and firmware must be fixed by them or the manufacturer HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
128Warning	Software error code 128 Software error code 128 What you can do Make sure the system is online so it can receive updates Restart the system once using the owner steps in your manual If the alarm stays, call your installer - settings and firmware must be fixed by them or the manufacturer HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
129Warning	Software error code 129 Software error code 129 What you can do Make sure the system is online so it can receive updates Restart the system once using the owner steps in your manual If the alarm stays, call your installer - settings and firmware must be fixed by them or the manufacturer HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
130Fault	Offline Offline What you can do Note the code, date and time and check the monitoring app Restart the system once using the owner shutdown/start-up steps in your manual if it allows If it comes back, call your installer HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
141Warning	Grid overvoltage Grid overvoltage What you can do This is usually caused by the mains supply, not the solar system The inverter normally reconnects by itself once grid voltage is back in range If it happens often (especially on sunny afternoons), note the times and call your installer - they can check the voltage and settings and talk to the network if needed HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
142Warning	Grid overvoltage (10-minute average value) Grid overvoltage (10-minute average value) What you can do This is usually caused by the mains supply, not the solar system The inverter normally reconnects by itself once grid voltage is back in range If it happens often (especially on sunny afternoons), note the times and call your installer - they can check the voltage and settings and talk to the network if needed HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
143Warning	Grid undervoltage Grid undervoltage What you can do This is usually caused by the mains supply, not the solar system The inverter normally reconnects by itself once grid voltage is back in range If it happens often (especially on sunny afternoons), note the times and call your installer - they can check the voltage and settings and talk to the network if needed HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
144Warning	Grid overfrequency Grid overfrequency What you can do This is caused by the mains frequency moving outside the allowed range, usually briefly The inverter reconnects by itself once the grid is stable If it keeps happening, note the times and call your installer HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
145Warning	Grid underfrequency Grid underfrequency What you can do This is caused by the mains frequency moving outside the allowed range, usually briefly The inverter reconnects by itself once the grid is stable If it keeps happening, note the times and call your installer HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
146Warning	Rapid grid frequency changes Rapid grid frequency changes What you can do This is caused by the mains frequency moving outside the allowed range, usually briefly The inverter reconnects by itself once the grid is stable If it keeps happening, note the times and call your installer HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
148Info	Grid disconnection Grid disconnection What you can do Check whether the rest of your house or street has power, and check your network operator's outage map Check the switchboard for a tripped solar/inverter breaker - reset it once only; if it trips again, leave it off and call an electrician Once normal power is back the inverter usually reconnects on its own within a few minutes If the power is normal but the alarm stays, call your installer HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
149Warning	Island detected Island detected What you can do Check that your home Wi-Fi/internet is working and restart your router Wait an hour - monitoring often reconnects by itself If the inverter screen also shows a fault, or the alarm stays for more than a day, call your installer HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
205Fault	Input port 1 overvoltage Input port 1 overvoltage What you can do Do not touch the DC isolators or cables Note the time - this often shows on cold, very sunny mornings Call your installer - the panel strings may need to be checked against the inverter's limits HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
206Fault	Input port 2 overvoltage Input port 2 overvoltage What you can do Do not touch the DC isolators or cables Note the time - this often shows on cold, very sunny mornings Call your installer - the panel strings may need to be checked against the inverter's limits HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
207Fault	Input port 1 undervoltage Input port 1 undervoltage What you can do Note the code, date and time and check the monitoring app Restart the system once using the owner shutdown/start-up steps in your manual if it allows If it comes back, call your installer HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
208Fault	Input port 2 undervoltage Input port 2 undervoltage What you can do Note the code, date and time and check the monitoring app Restart the system once using the owner shutdown/start-up steps in your manual if it allows If it comes back, call your installer HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
301Fault	Hardware error code 302 Hardware error code 302 What you can do Note the code, then restart the system once using the owner shutdown/start-up steps in your manual If the code comes back, call your installer - this is an internal fault that needs a licensed electrician or the manufacturer HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
302Fault	Hardware error code 302 Hardware error code 302 What you can do Note the code, then restart the system once using the owner shutdown/start-up steps in your manual If the code comes back, call your installer - this is an internal fault that needs a licensed electrician or the manufacturer HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
303Fault	Hardware error code 303 Hardware error code 303 What you can do Note the code, then restart the system once using the owner shutdown/start-up steps in your manual If the code comes back, call your installer - this is an internal fault that needs a licensed electrician or the manufacturer HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
304Fault	Hardware error code 304 Hardware error code 304 What you can do Note the code, then restart the system once using the owner shutdown/start-up steps in your manual If the code comes back, call your installer - this is an internal fault that needs a licensed electrician or the manufacturer HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
305Fault	Hardware error code 305 Hardware error code 305 What you can do Note the code, then restart the system once using the owner shutdown/start-up steps in your manual If the code comes back, call your installer - this is an internal fault that needs a licensed electrician or the manufacturer HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
306Fault	Hardware error code 306 Hardware error code 306 What you can do Note the code, then restart the system once using the owner shutdown/start-up steps in your manual If the code comes back, call your installer - this is an internal fault that needs a licensed electrician or the manufacturer HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
307Fault	Hardware error code 307 Hardware error code 307 What you can do Note the code, then restart the system once using the owner shutdown/start-up steps in your manual If the code comes back, call your installer - this is an internal fault that needs a licensed electrician or the manufacturer HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
308Fault	Hardware error code 308 Hardware error code 308 What you can do Note the code, then restart the system once using the owner shutdown/start-up steps in your manual If the code comes back, call your installer - this is an internal fault that needs a licensed electrician or the manufacturer HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
2Fault	Check the connection to the utility grid. Verify that the utility power is present at the microinverter in question by removing AC, then DC power. Never disconnect the DC wires while the microinverter is producing power. Re-connect the DC module connectors and watch for five short LED flashes. Check the connection to the utility grid. Verify that the utility power is present at the microinverter in question by removing AC, then DC power. Never disconnect the DC wires while the microinverter is producing power. Re-connect the DC module connectors and watch for five short LED flashes. What you can do Note the code, date and time and check the monitoring app Restart the system once using the owner shutdown/start-up steps in your manual if it allows If it comes back, call your installer HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter
6Fault	Verify that the PV module DC voltage is within the allowable range shown in the Technical Data appendix of this manual. Verify that the PV module DC voltage is within the allowable range shown in the Technical Data appendix of this manual. What you can do Note the code and the battery state of charge shown in the app Let the system run - some battery voltage protections clear by themselves after charging or discharging If the alarm stays or keeps returning, call your installer - don't open or disconnect the battery yourself HMS microinverters · Guide only. All work must be done by a licensed electrician.	HMS microinverters	Inverter

Common Hoymiles questions

What does Hoymiles 130 "Offline" mean?

Offline Note the code, date and time and check the monitoring app This is a guide only; any electrical work must be done by a licensed electrician.

What does Hoymiles 205 "Input port 1 overvoltage" mean?

Input port 1 overvoltage Do not touch the DC isolators or cables This is a guide only; any electrical work must be done by a licensed electrician.

What does Hoymiles 206 "Input port 2 overvoltage" mean?

Input port 2 overvoltage Do not touch the DC isolators or cables This is a guide only; any electrical work must be done by a licensed electrician.

What does Hoymiles 207 "Input port 1 undervoltage" mean?

Input port 1 undervoltage Note the code, date and time and check the monitoring app This is a guide only; any electrical work must be done by a licensed electrician.

What does Hoymiles 208 "Input port 2 undervoltage" mean?

Input port 2 undervoltage Note the code, date and time and check the monitoring app This is a guide only; any electrical work must be done by a licensed electrician.

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Total Solar can help: our licensed electricians install and service systems. Based in Ellenbrook, WA, with Victoria and Queensland also available.

Or call 1300 209 503

Sources

Meanings are summarised from these manufacturer documents. Check your own model's manual, as codes vary between models and firmware versions.

Hoymiles HMS User Manual (2025-06), 6.1 Troubleshooting

Hoymiles is a trademark of its owner. Total Solar is not affiliated with the manufacturer unless stated. All fault code guides

Common Hoymiles questions

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