Fronius Primo, Symo & GEN24 String Inverter State Code RMA & Warranty Playbook
How to decode Fronius inverter State Codes (State 107, State 306, State 475, State 509, State 522), use Fronius SOS self-service to verify your 10-year Indiana factory warranty, and swap the snap-off power stage without removing the wall mounting bracket.
1. Factory Diagnostic & Direct RMA Submission Protocol
Step 1 — Read the 3-Digit "STATE XXX" Code on the Fronius LCD Display: Press the capacitive buttons underneath the Fronius Primo LCD screen to wake the display and record the 3-digit State Code: State 100-series = AC Grid issues; State 300-series = AC/DC Power Stage hardware issues; State 400-series = Communication / Isolation faults; State 500-series = DC MPPT input faults.
Step 2 — Check Your Serial Number on the Fronius SOS (Solar Online Support) Portal: Locate the 8-digit Fronius Serial Number on the bottom sticker underneath the DC disconnect switch. Enter the serial number at sos.fronius.com or call Fronius USA in Portage, Indiana at (219) 734-5500 to check your active 10-year (or extended 15/20-year) warranty coverage.
Step 3 — Distinguish Between State 475 (Roof Ground Fault) vs. State 306/307/522 (Internal Power Stage RMA): If your screen reads "STATE 475" (Solar panel ground fault — isolation resistance <1 MOhm), the inverter is healthy and protecting your home from a pinched or wet wire on the roof! Conversely, persistent State 306, State 307, State 516, or State 522 when DC input voltage is normal indicates an internal DC-DC MPPT board failure covered by Fronius RMA.
Step 4 — Use Fronius’s SnapINverter Hinge Design for a 15-Minute Power Stage Swap: Just like SolarEdge, Fronius Primo and Symo "SnapINverters" hinge out from a separate wall-mounted wiring bracket. When Fronius USA ships your replacement RMA power stage from Indiana, any licensed electrician can unclip the old body and snap the new inverter onto your existing wall bracket in 15 minutes!
2. Electrical Telemetry & Voltage Proof Sheet
Cross-Reference Inverter Fault Codes →FRONIUS PRIMO / SYMO STATE CODE RMA DIAGNOSTIC CHART ================================================================================ Fronius State Code Official Meaning Action Required -------------------------------------------------------------------------------- STATE 102 / 107 AC Grid Voltage Outside Limits Check 240V Breaker / Utility Voltage STATE 306 / 307 Low PV Output / DC-DC Stage Fault Test String Voc -> Fronius Inverter RMA STATE 475 Isolation Fault (Ground Leakage) Inspect Roof Conduit & Wet MC4 Plugs STATE 522 / 523 DC Input MPPT2 / MPPT1 Hardware Low Swap MPPT1/MPPT2 Strings to Confirm RMA
Fronius USA LLC (Portage, Indiana USA) Warranty & RMA FAQ
How do I prove to Fronius Support whether State 522 is caused by a bad roof string or a bad inverter MPPT?
Turn the bottom black DC disconnect rotary switch to OFF, open the lower wiring cover, and physically swap PV String 1 and PV String 2 between MPPT1 and MPPT2! If the State 522 error stays on MPPT2 even with the known-good solar string connected, the inverter’s internal MPPT2 board is 100% proven defective and Fronius will approve the RMA on the spot.
My Fronius Primo screen is completely blank at night ("Night Switch-Off"). Is it broken?
No! By default, Fronius string inverters derive their screen power from the DC solar array so they consume 0 Watts from your electric bill overnight. Unless "Night Mode: ON" is manually enabled in the setup menu, a Fronius inverter always goes dark after sunset and wakes up automatically at sunrise.
How do I transfer Fronius Solar.web monitoring if my installer went out of business?
Email [email protected] with a photo of your inverter’s bottom serial number sticker, your Datamanager ID, and a copy of your electric utility bill or property deed; Fronius USA in Indiana will reassign your Solar.web plant ownership directly to your email address for free.