1. Take the batteries out of the thermostat.
2. Push the summer/winter button (sun/snowflake icon) so that it is popped out.
3. Allow a few seconds for the thermostat to power down, then put the batteries back in or replace with new batteries if required.
4. Turn the temperature up on the thermostat so that the flame symbol appears.
5. Push the summer/winter button back in on the boiler, this should then re-connect.

To set the time/tempertaures - (See below)

QUICK GUIDE - constant heating
Check temperatures on the thermostat
SUN should be 23
MOON should be 8

1. Set the slider to the 'RUN' position
2. Press 'HOLD' for a few seconds then use to arrows ^ to set the desired temperature.
3. It will then revert back to the current room temperature and start to rise.
4. To cancel the override. Press 'HOLD' and it will resume back to the programmed settings.