If your Thermostat is showing a temperature of 1°C, there are two likely causes:
The Thermostat has been placed somewhere very cold
For example, the Thermostat may have been temporarily placed in a fridge or another cold location.
Check your heating graphs in your account. If you see the temperature rapidly drop to around 1°C and then return to a normal room temperature shortly afterwards, this is likely to be the cause.
It is also worth looking for a pattern. For example, does the temperature drop happen at around the same time each day?
The temperature sensor may be damaged
If the Thermostat has not been placed in a cold location and continues to show an unusually low temperature, the internal temperature sensor may have been damaged.
Please contact our support team so that we can investigate this further.