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Usually self-clears

Deye F35: No AC Grid Detected

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

F35 means your Deye inverter can't detect the utility grid, so a grid-tied system stops exporting and protects itself. Most of the time this is not an inverter fault at all. It's usually a power cut or a tripped breaker between the inverter and the grid. When the grid comes back, F35 normally clears on its own.

Is it you, the grid, or the inverter?

F35 is almost always on the grid side. Most common first:

  • A utility power cut. Check if the lights and other outlets in the house are also dead. If the whole house is out, it's the grid, just wait.
  • A tripped breaker or open isolator between the inverter and the meter/grid.
  • A loose AC connection at the inverter or distribution board.
  • Grid voltage or frequency out of range (a weak or unstable supply). The inverter waits until it's stable again.

The safe fix, step by step

Before you start All steps are external. Don't open the inverter or work on wiring.
  1. Check for a power cut. Look at the rest of the house, or ask a neighbor. If the grid is down, there's nothing to fix, F35 clears when power returns.
  2. Check the AC breaker and isolator. Find the breaker/isolator between the inverter and the grid and make sure it's on. Reset it if it tripped.
  3. Look at the main supply. Confirm the main breaker and the meter have power.
  4. Give it a few minutes. After power returns, the inverter runs a short reconnection delay before it goes back online. This is normal.
  5. If grid is clearly present but F35 stays. Do a safe power cycle (AC off, then DC isolator off, wait 5 minutes, restart). If it still won't connect, the AC connection or the inverter's grid-detection may need a look.

Quick decision flowchart

F35 appears
↓ is the rest of the house also without power?
✅ Yes, whole house is out → it's a grid power cut. Wait; F35 clears when power returns.
❌ No, the house has power → check the AC breaker/isolator to the inverter (steps 2 to 3).
↓ breaker on, grid present, still F35
Power-cycle once. If it still won't connect, contact your installer to check the AC connection and grid settings.
When to call a professional If the grid is definitely present (the house has power and the breaker is on) and F35 keeps coming back after a restart, the AC wiring connection or the inverter's grid-detection circuit may need service. That's an installer job.

Related Deye codes

F42, AC line low voltage F47, AC over frequency F18, AC overcurrent

FAQ

F35 shows but my house has power. Why?

The inverter sees the grid through its own AC connection. If a breaker or isolator on that line is off, or a connection is loose, the inverter reads "no grid" even though the house is powered. Check that breaker first.

Will my system still work on battery during F35?

On a hybrid system with backup, your battery can keep backup loads running during a real grid outage. F35 just reflects that the grid is absent; the inverter reconnects and resumes grid functions when power returns.

How long until F35 clears after power returns?

Grid-tied inverters wait a short, standards-required reconnection delay (often a few minutes) after the grid is stable before they go back online. A short wait is normal.

Sources

  • Deye Hybrid Inverter User Manual (F35 = "No AC grid"; check grid status and the connections/switches between inverter and grid).
  • Deye dealer technical references for grid-side fault codes.
⚠️ Safety disclaimer. Solar inverters carry lethal DC and AC voltage even when "off". This guide covers external, switch-level steps only. Never open the unit or work on wiring unless qualified. When in doubt, call a licensed installer or electrician.