A temperature offset can be applied if a radiator thermostat is located in an unfavourable place in a room (behind a cupboard, close to a draughty window or behind a curtain) and the temperature measured there differs from the actual room temperature.
This can be compensated for with a temperature offset. A temperature offset is thus an error correction (temperature correction) of the existing temperature conditions in a room at the radiator thermostat. The temperature range for equalisation is usually between +/- 4 Kelvin.