If you have a hot water cylinder (and nine million UK homes do) how long will the hot water last before you need to heat the water again? If you don’t know, it will only take a day or so to work it out; you might find that you can start saving money by not heating the water as often. You could also be losing heat from the cylinder itself: modern cylinders should lose no more than 2kWh a day and some lose as little as 1kWh; copper cylinders with loose red jackets can lose up to 4kWh (although the loss will depend on insulation thickness and size of the cylinder – the bigger the cylinder the more it will lose – but it can soon add up to over 1,000kWh a year). For practical advice on protecting your cylinder from heat loss, visit theheatinghub.co.uk.