Hot water tank
Your hot water cylinder will be stored behind a cupboard door in your home, usually off the hallway. The size of your cylinder will depend on the size of your house. You shouldn't have to touch anything in your cylinder as it is all controlled using your heating controller. For more information on how to use these, see our videos heating and hot water controls.
If you ever lose any heating power, there is a water heater immerser switch on the wall below the cylinder. Switch that on and it will give you hot water, and then turn it back off once you're done.