Keep windows and doors shut not letting the heat escape.
Install window insulation, this is a plastic film applied to the glass which prevents heat loss.
Use curtains and blinds, close them once the sun goes down. This is like a layer of insulation
Use draft excluders. underneath closed doors to prevent drafts.
Get a rug if you have hard wooden or stone flooring to prevent heat loss to the cold floor
Wrap up warm, warm jumpers, fluffy socks and blankets.
Trying out a combination of these things should help a little towards your energy consumption. Long term term options replacing old boilers please feel free to contact organic heating Ltd as we are here to help however these tips you can put into action now to make a difference straight away.