SME"s can often save on energy bills the most by installing a HeatingSave control system to replace their existing central heating time clock. This is because many of these currently use a 24 hour heating clock with heating still on at weekends when many of them are not working. Even if they have installed a 7-day clock, this will still not handle bank holidays, which with shutdowns over Christmas can represent around 3%+ of the heating fuel used.