| 摘要 |
PURPOSE:To prevent temperature fall in outgoing hot water during the initiation of a second supply by a method wherein pre-purge is omitted when hot water is supplied for the second time before the expiration of a prescribed period of time following the end of the preveous supply of hot water. CONSTITUTION:In a forced-draft type tap-controlled water heater 1 provided with a fan 4 and a burner 3 directly ignited by an igniter 6, when a water-flow switch 7 to detect the supply of water to a heat exchanger 2 is turned ON for the first hot-water supply, the fan 4 is started for a pre-purge lasting several seconds, and then a gas solenoid valve 5 opens and the igniter 6 goes into action to ignite the burner 3. For a second supply of hot water within a certain period of time after a stoppage of the supply of hot water, the water-flow switch 7 is turned ON for the simultaneous activation of the fan 4, igniter 6, solenoid valve 5, for the ignition of the burner 3 without a pre-purge. |
