Heat only boilers are also known as open vent, conventional or regular boilers. They heat your central heating and hot water when installed as part of a heating system together with a hot water storage cylinder, cold water storage tank, plus a feed and expansion tank (which is usually stored in the loft above the boiler to provide a good head of water). If the boiler you’re replacing is very old, it is most likely a heat only boiler. One of the other clues is that you’ll have a separate circulating pump, instead of one inside the boiler. We keep a huge stock of efficient condensing heat only boilers from all the leading brands such as Potterton, Worcester, Vaillant, Baxi and Glow-worm. In fact, we have all the heat only boilers you need at the lowest prices.