| 摘要 |
PROBLEM TO BE SOLVED: To provide a water heater with a high energy saving function minimizing dropping of heat efficiency of the water heater due to excessive air supply by properly controlling operation of an air supply fan. SOLUTION: If a combustion load is stable for predetermined time in an udder prevention region in a state switched to a first particular stage, an effective combustion range is forcibly transferred to a second particular stage while maintaining the combustion amount in the udder prevention region. COPYRIGHT: (C)2010,JPO&INPIT |
