Abstract: This invention relates to domestic heat and power systems that allow efficient methods of operating a domestic combined heat and power (dchp) unit and to energy-efficient methods of scheduling domestic appliance operation within a household having a dchp unit. Dchp units provide heating and hot water for the home and also generate electricity for use in the home. A domestic heat and power system is provided that comprises a dchp unit, a dchp unit controller, a programmer module and an energy scheduler linked to allow communication therebetween, wherein the programmer module receives data input and generates a heating and/or hot water schedule therefrom, the dchp unit controller determines operating times of the dchp unit in accordance with the schedule and provides the operating times to the energy scheduler that then operates the domestic appliance during operating times.