Thermostat shows P011 and humidity reading is missing or stuck at 0% or 100%.

Safety: No high‑voltage work is required. Do not spray cleaners directly on the thermostat.

• Step 1 – Visual inspection: Check the GLAS front for signs of moisture, condensation, or chemical residue. Wipe gently with a dry microfiber cloth only.
• Step 2 – Reboot: Power cycle the thermostat by removing it from the wall plate for 60 seconds, then reattach.
• Step 3 – Allow stabilization: After power‑up, allow 30–60 minutes for the humidity sensor to stabilize and update.
• Step 4 – Compare with another hygrometer: Place a known‑good humidity meter near the thermostat to confirm whether GLAS readings are inaccurate or missing.
• Step 5 – Firmware update: Install any available firmware updates from the GLAS settings menu.
• Step 6 – Replace thermostat: If P011 remains and humidity readings are not restored, the internal humidity sensor IC or sensor board is defective. Replace the GLAS thermostat.