HOT WATER STORAGE TYPE WATER HEATER

PROBLEM TO BE SOLVED: To provide a user-friendly hot water storage type water heater that enables prompt determination of starting of use for hot water supply and prompt use of desired hot water.SOLUTION: A hot water storage type water heater includes: a hot water storage can body 1 having hot water stored therein; a burner section 3 for heating hot water within the hot water storage can body 1; hot water storage temperature detection means 12 for detecting a temperature of hot water within the hot water storage can body 1; and a control section 16 for controlling combustion of the burner section 3 on the basis of a temperature detected by the hot water storage temperature detection means 12 to maintain the temperature of the hot water within the hot water storage can body 1 at a set hot water storage temperature. The hot water storage type water heater further includes hot water supply start determination means 17 for determining starting of use for hot water supply. The hot water supply start determination means 17 determines whether or not use for hot water supply has been started, from a value of a secondary derivative relative to a current detection temperature obtained by the hot water storage temperature detection means 12, which is calculated based on the current detection temperature and past detection temperatures detected by the hot water storage temperature detection means 12. The control section 16 starts the combustion of the burner section 3 when the hot water supply start determination means 17 determines that the use for hot water supply has been started.SELECTED DRAWING: Figure 2 【課題】給湯の使用開始を素早く判断し、所望の湯をすぐに使用できる使い勝手のよい貯湯式給湯装置を提供する。【解決手段】内部に湯水を貯湯する貯湯缶体１と、貯湯缶体１内の湯水を加熱するバーナ部３と、貯湯缶体１内の湯水の温度を検出する貯湯温度検出手段１２と、貯湯缶体１内の湯水の温度を設定貯湯温度に保持するよう貯湯温度検出手段１２で検出される温度に基づいてバーナ部３の燃焼を制御する制御部１６とを備えたものにおいて、給湯使用開始を判断する給湯開始判断手段１７を設け、給湯開始判断手段１７は、貯湯温度検出手段１２の検出する現在の検出温度および過去の検出温度に基づいて算出される現在の貯湯温度検出手段１２の検出温度に対する二次導関数の値から、給湯使用が開始されたか否かを判断し、制御部１６は、給湯開始判断手段１７により給湯の使用が開始されたと判断されたときに、バーナ部３の燃焼を開始させるようにした。【選択図】 図２