Heating help

Trying to work out how to fix our thermostat system so we can have the heating on a timer again.... (as this is a backblip I now know we finally sorted it on Wednesday when we called Mark who came round with Noah and sorted it within a few minutes... and meant we didn’t have to buy a new one of these for £60 because he just isolated this so we could just use our fancy programmable one on its own instead!).