Fitting a British Standard "jacket" to your hot water storage tank will cut heat loss by around 75% and save you money. They are cheap and easy to fit and can be found in any good DIY store and, if you already have a jacket fitted to your hot water cylinder, check that it's at least 75mm (3") thick. If not replace it with a new one.
You can also find foam pipe insulation in most DIY stores, which is cheap and easy to fit. Fit this for primary hot water pipes and starts saving money very quickly.
