E04 error and thermostat cannot read floor sensor temperature in floor‑heating mode

Safety: Turn off power to the heating system at the breaker before touching any wiring.

• Step 1 – Verify configuration:
  • In the thermostat menu, confirm that Floor Sensor is enabled if you are using one.
  • Ensure the correct sensor type (e.g., 10k NTC) is selected per Gosund model specifications.
• Step 2 – Inspect sensor wiring:
  • Remove the thermostat from the wall plate.
  • Locate the floor sensor terminals (often labeled “S1/S2” or similar).
  • Ensure both sensor wires are firmly clamped and not broken or frayed.
• Step 3 – Test sensor resistance:
  • Disconnect the sensor wires from the thermostat.
  • Use a multimeter to measure resistance across the two sensor leads.
  • Compare the reading to the Gosund sensor chart (e.g., ~10kΩ at 25°C for a 10k NTC).
  • If the reading is infinite (open) or near 0Ω (short), the sensor is defective.
• Step 4 – Replace floor sensor if faulty:
  • Pull the old sensor cable out of the conduit if possible.
  • Feed the new Gosund‑compatible floor sensor probe through the conduit to the floor area.
  • Connect the new sensor to the thermostat terminals and secure.
• Step 5 – Clear error:
  • Restore power and verify that E04 is cleared and floor temperature is displayed correctly.