Please advice: the central heating has been out of order for a few years, and I want to install a thermostat to the water cylinder in order to have hot water, how is that done and what would be the cost?
You need to install one of these 12461 [screwfix part number]. Turn off water to cylinder, remove plug [special spanner required] and install heating element, size and wattage will dictate how much water is heated and speed it is heated.You will need a local power supply to power the element, size again dictated by wattage used.