Heating Equipment

The modular heat store 1 comprises a plurality of heat store modules 2. Each module comprises a chamber holding a mass of phase change material 3 (PCM), a heat exchanger 4 to transfer heat between the PCM and a heat transfer fluid; and connectors (5, figure 1) to enable one or more of the modules to be fluidly connected to one another. The PCM is preferably a hydrated salt having a phase transition temperature of between 30ËšC and 90ËšC. Each module can include an annular cavity 8 closed by a lid 11 to define the chamber. A raised lip 12 permits easy opening of the lid when needed. Each module is ideally less than 20cm in height and can be stacked on other modules. Such an arrangement provides easy installation of the modular store since modules filled with PCM are smaller and less heavy than conventional thermal stores. The modular store can be used as part of a domestic hot water or space heating system, whereby a heat source (15, figure 6A) such as a solar thermal system or a heat pump can provide thermal energy to the store for use later.