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Deye F08: GFDI Relay Failure

Updated June 2026 · Reviewed for technical accuracy · ~3 min read

F08 points to a problem with the inverter's GFDI (Ground-Fault Detector Interrupter), the protection that watches for dangerous leakage current to ground. Because this is a safety device, a real or persistent F08 should be checked by a professional rather than repeatedly reset. There is one common, safe thing to verify first: the neutral-to-ground bonding.

What F08 usually means

Incorrect neutral-to-ground bonding on the backup (EPS) output, common in split-phase and three-phase systems. The N line must be properly grounded as the manual specifies.
A ground-fault or leakage condition somewhere in the system that the GFDI has caught.
A genuine fault in the GFDI relay/circuit itself.

What to do, safely

Before you start Grounding and bonding involve protective wiring. The only owner-level action is to check whether the system was recently changed and to power-cycle once. Anything involving the N-to-ground bond or internal relay is an installer job.

Note any recent changes. Did F08 start after new wiring, a new backup connection, or an install change? That points to a bonding issue introduced during the work.
Do one safe power cycle. Turn off the AC breaker, then the DC isolator, wait 5 minutes, then restart. A one-time glitch may clear.
If F08 returns, stop. Do not keep resetting a ground-fault protection alarm. Repeatedly clearing a safety device defeats its purpose.
Call your installer. They will verify the neutral-to-ground bonding per the Deye manual for your system type, check for a real ground fault, and confirm the GFDI circuit is healthy.

Quick decision flowchart

F08 appears

↓ power-cycle once

✅ Cleared and stays gone → likely a one-time glitch. Keep an eye on it.

❌ Returns → ground-fault/bonding or GFDI circuit issue. Don't keep resetting.

↓

Have your installer verify N-to-ground bonding and check for a ground fault.

When to call a professional Any F08 that returns after a single restart should be inspected. It involves ground-fault protection, a safety function, so the correct response is a qualified check of the bonding and the GFDI circuit, not repeated resets.

Related Deye codes

F24, DC insulation failure F23, AC leakage current F63, Arc fault

FAQ

F08 started right after my system was installed or modified. Coincidence?

Usually not. A new F08 right after wiring work very often points to the neutral-to-ground bonding on the backup output. Ask whoever did the work to verify the bonding against the Deye manual for your configuration.

Can I keep using the system with F08?

The GFDI is a safety protection. If it's flagging a fault, you shouldn't bypass or ignore it. Get it checked before relying on the system.

Is F08 the same as a tripping RCD/GFCI in my house?

They're related in spirit (both detect leakage to ground) but F08 is the inverter's own ground-fault protection reporting an issue on the solar/backup side. The fix is on the inverter's grounding and circuit, not your household RCD.

Sources

Deye Hybrid Inverter User Manual (F08 = "GFDI relay failure"; ensure backup N line is grounded in split-phase/three-phase, contact support if it persists).
Deye dealer technical references for ground-fault protection codes.

⚠️ Safety disclaimer. F08 involves ground-fault protection. Solar inverters carry lethal DC and AC voltage. This guide covers only noting recent changes and a single safe power cycle. Grounding, bonding, and internal relay checks must be done by a licensed installer or electrician.