The thermostat is set at 18.5.
The heating comes on twice a day and if the temperature falls to 17.0 in the daytime we advnce it so that it comes back on again immediately and the temperature comes back up to 18.5.
For those setting temeoratures for lower figures. If you read any of the advice given to people everywhere, especially older people, you will know that if the temperature falls below 18 degrees for any significant period,, it is bad for your health,
Hypothermia is an insidious danger that comes on gradually and you do not notice it. I know I am prone to it. It is not worth putting your life at risk.