Make sure you know how to operate your heating and hot water - do not just guess. If you need help give us a ring and we can come out and show you how it all works properly. You can find guides onhow to operate your boiler here.
There is a thermostatic valve on your room radiator so that you can individually adjust the heating in each room. If you go away for a couple of days, turn the thermostat right down so you are not heating an empty room.You can see how to use these here.
Most houses also have ahouse thermostat, work out what this needs to be set to in order to ensure the house is warm. If your room is cold but others are too hot (a sun facing room or a larger room makes a big difference) turn the thermostat up a degree and have your house mates turn their radiator thermostats down.
Try to avoid having the heating on and windows open - you are just trying to heat Leeds.
You should never need any additional electrical heaters (and they consume huge amounts of energy). If you are still cold when the heating is on something is wrong, so let us know.
Turn off the lights when you leave a room (leave a single light on when everyone is out to deter burglars).