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Solar · Error codes · GoodWe Technologies Co., Ltd.
25GoodWe Technologies Co., Ltd. · GoodWe ET / ET Plus+ (5-10 kW)

25 on a GoodWe Technologies Co., Ltd. GoodWe ET / ET Plus+: Relay check failure - Neutral & ground not well connected

Short answer

On a GoodWe Technologies Co., Ltd. inverter, 25 means: Relay check failure - Neutral & ground not well connected. The inverter stops until the fault clears or is reset. An engineer is needed to fix the cause.

Reviewed 24 September 2026 · 1 source

What it means

The manual says: Relay check failure - Neutral & ground not well connected.

Part involved: output relay / earthing.

Likely causes:

  • Neutral & ground not well connected; utility ground loss. | Troubleshooting: Measure N-PE on grid (<10 V); measure ground-neutral on backup (<10 Ohm); contact service.

Is it safe?

Does the inverter stop?Yes
Engineer needed?Yes

The inverter stops until the fault clears or is reset.

Resetting itself: unknown.

Manual reset: Restart per GoodWe troubleshooting guide.

What you can check

  • Check the inverter LEDs (FAULT LED on = fault) and read the alarm in the SEMS Portal app or SolarGo app; note code, message and time for your installer.
  • Contact your installer.

What the engineer will check

  • N-PE voltage/backup earth checks.

Who to ask for: GoodWe-trained installer / MCS PV & battery installer.

Certification: Qualified electrician (BS 7671; MCS-certified PV installer for work on the PV array/DC side).

What you might notice

Sources

A code explains what the controller detected, not a confirmed root cause.

Reviewed: 24 September 2026