The use of gas cooking ranges makes it necessary to provide separate means for heating water. This is accomplished in several ways. The range shown in Fig. 52 has a boiler attached which is provided with a separate burner.

Fig. 61 shows a gas heater attached to the ordinary kitchen boiler. A section through the heater is shown in Fig. 62. This consists of a chamber surrounded by an outer jacket with an air space between. Circulation pipes, through which the water passes, are hung in the inner chamber just above a powerful gas-burner placed at the bottom of the heater.

A heater of different form for heating larger quantities of water is shown in Fig.. 63 and 64. This consists, as in the case just described, of a circulation coil suspended above a series of burners. The supply of gas admitted to the burners is regulated by an automatic valve, which is opened more or less as the flow of water through the heater is increased or diminished. When no water is being used, the gas is shut off from the burners, and only a small "pilot light," which takes its supply from above the automatic valve, is left burning. As soon as a faucet in any part of the building is opened and a flow of water started through the heater, the automatic valve opens, admitting gas to the main burners, which is ignited by the pilot light, and in a few moments hot water will flow from the faucet. The heater shown has a capacity of 9 gallons per minute from a temperature of 55 to 130°.

Hot Water Heaters 1000354

Fig. 68.

Hot Water Heaters 1000355

Fig. 59.

Hot Water Heaters 1000356

Fig. 60.

Hot Water Heaters 1000357

Fig. 61.

Hot Water Heaters 1000358

Fig. 62.

Another type is that known as the instantaneous water heater, one form of which is shown in Fig. 65. This is made especially for bathrooms, and will produce a continuous stream of hot water whenever desired. The heater is shown in section in Fig. 66, in which A is the gas valve, B the water valve, D the pilot light, FF the burners, I a conical heating ring, J a disc to retard and spread the rising heat, K a perforated copper screen, and L a revolving water distributer. In this heater the water is exposed directly to the heated air and gases in addition to its passing over the heated surface of the ring I. The upward arrows show the path of the heat, and the downward arrows the passage of the water.

Hot Water Heaters 1000359

Fig. 63.

Hot Water Heaters 1000360

Fig. 64.