hello there. just had a new combi boiler with the above room thermostat. all is good except for some reason even tho the thermostat is set to turn off and on at specific times, it doesnt seem to be doing. you can set the temperature and the on off time on this thermostat but it just keeps on running. i have to turn it off manually at night or i will melt. My plumber is a good guy and will sort it, but hes not used this thermostat before and we just can understand why it wont go off. any ideas?