Fronius build reliable solar inverters, however, did you know there are over 100 potential Fronius error codes? Most of which are not related to the inverter directly and more associated with external influences. That’s why it’s important to have a knowledgeable and resourceful partner on your side when installing a Fronius inverter as part of your new energy system. 


The Solar Review community understands intelligent technologies such as Fronius. Compiled below are the 6 steps to resolving your Fronius error codes. If you reach the end and find yourself more confused than when you first started, try leaving a question in the comments section at the bottom of this post for some expert feed back.

1. Identify the code.

Fronius Fault Codes

Fronius error codes are delivered in a simple three number format. Write these numbers down or even better take a photo with your smartphone (future sharing and logging purposes if required).

2. Environmental conditions.

Ensuring your environmental conditions are as close to optimal as possible will aid better diagnosis of particular Fronius error codes. What’s meant by this? Assess the environment associated directly with the solar array.

  • Are the local conditions Sunny or cloudy?
  • Is the temperature an extreme? (greater than 35 or less than 5 degrees Celsius)
  • Is there soiling inhibiting the production of the solar panels? (Bird excrement, excessive dust)
  • Is the inverter adequately ventilated? (no inhibiting external factors since installation)

3. Prior events.

Were there any significant external influences or events which may have caused the associated Fronius error code to arise? Identifying such influences could ensure an expedited resolution. Withholding information could simply delay the inevitable as a testing process is required for advanced Fronius error codes and potential warranty claims. Prior to noticing the Fronius error code was there:

  • Excessive rain?
  • Lightning or thunder in your localised region?
  • Building related disturbances to the wiring or structure?
  • Power outages noticed from you grid supply? (Did you have to reset any clocks in your building?)

4. Solar.web log (if available).

Fronius Solarweb PV System Comparison

If connected to the internet through your WiFi connection, Fronius error codes can also be reported through email and the Fronius Solar.web logging feature – great for identifying trends. Additionally, this is often the most responsive way of identifying Fronius error codes as they are reported within a short period of occurrence or immediately if set-up correctly. Solar Review technicians recommend all Fronius inverter owners identify that their Fronius inverter is connected to the internet on a weekly basis via logging into the Solar.web app, ensuring the recorded information is up to date and reporting as expected.

To access service messages via Fronius Solar.web visit > Login > Service Messages (Tab) > Service Messages redirect to old site > OK

5. Review the code.

Identify then act. This page is intended to aid self-resolution and identify prospective causes. The video provided is to assist customers navigate the Solar Review site to locate the Fronius error codes main page when all you have is Google. Progressing forward is where Solar Review truly flexes its technical, online muscle, with an in-depth 24/7 solution. For a direct link CLICK HERE >

6. Take action.

With the 5-prior steps above covered you now are equipped with the knowledge to assist a resolution for your Fronius error codes! If however, you are even more confused than when you started try leaving a comment below for assistance from the Solar Review community. Here’s that video again.

Rest assured.

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Leave your comments below and join the discussion!

Related research.

SHORTCUT: Jump straight to the Solar Review error codes list . VIEW >


  1. Yo tengo un error 102. Sé que significa que hay un voltaje elevado en la red, pero al medir la red sin conectar el inversor, el voltaje está correcto en 230 V como máximo. Al energizar el inversor, este se enciende como es natural y el voltaje se mantiene en torno a los 230 V. Al cerrar swch DC el inversor comienza a levantar potencia fotovoltaica, y junto con ello se comienza a aumentar el voltaje hasta llegar a los 248 V en un intervalo de 5 minutos aproximadamente. De acuerdo a con esto no entiendo como puede marcar error de red si el problema empieza al conectar el inversor. Favor sus comentarios y soluciones que han logrado en otros casos. Gracias

    • If this happens all the time the most likely cause is the cable size is too small within the intended circuit which facilitates the solar supply? This could either be the Inverter AC supply cable, sub-mains cable to the distribution point or even the mains cable to the property in certain scenarios. The inverter is programmed to stop at a certain point often governed by your location settings to ensure the grid integrity. Check your cable sizes from the inverter to the point of supply to ensure minimal resistance. Adjusting resistance (with correct cable sizing) facilitates ease of current flow which in turn will keep volatge rise down. Goodluck!

  2. Hi all, We’ve just moved into a new house that has the Fronius Primo. It is pretty much continuously cycling through Error Code 102. Who do I call, Installer (who I don’t know yet, new house and all), Energy supplier or Fronius? And is there a user manual somewhere online I can download?


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