Abstract: A domestic gas storage water heater utilizes a plastic non pressure tank to deliver mains pressure hot water. The heater may be external or internal of the tank and has a heat out put of about 4-10 Mega joules per hour. A pressure transfer module uses the mains pressure of the incoming cold water to deliver hot water from the tank at mains pressure. The tank may be of larger storage capacity than conventional gas heaters and the arrangement ensures that the heated water in the tank is stratified into layers of different temperature. This enables an uninterrupted supply of hot water to be achieved.

Abstract: A domestic water heater 10 includes a water meter 14 to count the units of water used each day and has a timer 17 to time the heating cycle each day. A programmable means 18 stores the water usage and heating data for a sixty day period and using statistical techniques determines the time period required for heating the water in the tank 10. The means 18 also stores power load curve data from the power generator and matches the required heating time to an appropriate portion of a low in the power load curve. The tanks may be placed in any one of 9 groups and a tank in each group will by virtue of the program in means 18 center the mid point of the calculated heating period on the same time during the off peak period. Tanks fitted with such controllers can be allocated into one of two or more categories to enable a power utility to reallocate the water heater power load into low cost periods of the power load curve.

Abstract: An electric power distribution system that utilises radio signals from the power distributor to an appliance such as a water heater 1, to inform via a receiver 12, a micro processor 10 of the energy priority rating of the power distributor. The water heater has an array of temperature sensors 5 that determines the average temperature of the tank and enables the microprocessor 10 to generate an energy needs rating for the water heater. The microprocessor is programmed with a decision algorithm that uses the needs and priority ratings to either switch the appliance on or off.