Thermostat or TRV shows condensation inside the display or housing, and operation is erratic.

Safety: If moisture is visible inside a mains-powered thermostat, isolate power immediately to avoid electric shock.

• Dry the device: Remove the thermostat or TRV from its mounting and place it in a warm, dry room for 24–48 hours. Do not use direct heat sources like ovens.
• Check installation location: Avoid installing non-IP-rated Eurotronic thermostats in bathrooms or directly above humidifiers.
• Inspect seals: For TRVs, check that the battery cover and housing seals are intact and properly closed.
• Prevent future moisture: Improve room ventilation and avoid water splashes near the device.
• Replace device: If corrosion or persistent malfunction is observed after drying, replace the thermostat or TRV.