Circulation type hot water supply device

A circulation type hot water supply device comprising a water heater having a hot water supply heat exchanger, a burner that heats water supplied to the heat exchanger from a water supply channel upstream of the heat exchanger, and delivered hot water temperature detection means for detecting a temperature of hot water fed from the heat exchanger to a hot water delivering channel downstream of the heat exchanger, a hot water delivering tap being connected to the hot water delivering channel which is connected at the downstream end thereof to the water supply channel, and a circulating pump that returns the hot water fed from the heat exchanger to the hot water delivering channel to the heat exchanger through the water supply channel being provided in the hot water delivering channel,

• the device further comprising:
• a condition determination processing portion that determines whether a first condition that the hot water delivering tap is closed and a second condition that the burner is subjected to combustion are met;
• and
• a diagnosis processing portion that diagnoses the presence or absence of an abnormality of the heat exchanger in the case where the condition determination processing portion determines that both the first and second conditions are met,
• wherein the diagnosis processing portion has a stop processing portion that stops supply of water to the heat exchanger to stop combustion of the burner, and an abnormality determination processing portion that determines the presence of an abnormality in the case where an amount of increase of a detection temperature detected by the delivered hot water temperature detection means reaches a predetermined threshold value or more after the stop processing portion stops the supply of water.