A conventional boiler works by using two water tanks in the loft. One is a large storage tank for cold water, and the other is a smaller ‘feed and expansion’ tank used to keep the boiler topped-up. The water from the storage tank is fed down to the boiler, which heats it in a large cylinder. The boiler uses energy to keep the cylinder hot all day, even if no water is being used. Because of the size of the cylinder, conventional boilers can release a lot of water when required. This means that the shower can be ran at the same time as the taps, without either going cold.
Conventional boilers are best-suited for large houses or homes where a lot of hot water is used every day. When the hot water cylinder is empty in a modern boiler, it only takes around half an hour to fill and re-heat.
While conventional boilers heat the water all day, the efficiency of modern boilers means that this is not very expensive. Installing a modern boiler may reduce heating bills by over 30% compared to an older boiler. Conventional boilers are very reliable, although they require a substantial amount of space to store the tanks and cylinder, and therefore may be unsuitable for some homes. For small homes where not a lot of hot water is uses, a combination boiler may be a better alternative.
