In planning the hot-water supply for residences, the possibility of an adequate and economical supply without the usual hot-water tank and range waterback should not be overlooked. In residences where gas is used for cooking purposes, hot water for domestic use may likewise be heated at small cost by means of a Ruud type of water heater. Very little fuel is required by the pilot light, which is all the fuel used when water is not being drawn, while at the same time an inexhaustible supply of hot water is constantly at hand. In addition to the Ruud type of heaters there are apparatus which heat water instantaneously with gas but are available only for a few fixtures. These heaters may be had at low cost, will prove very satisfactory in many of the cheaper residences where a permanent supply of water is out of the question, and will be found equally serviceable for heating water at summer homes and camps. When desirable, alcohol, kerosene or gasoline may be used as a fuel instead of gas.