Hot water apparatus

Abstract

A valve device A of a hot water apparatus WH is capable of sequentially executing flow rate control in a temperature adjustment range mode and flow rate control in a flow rate adjustment range mode in a process where a rotation angle of a motor drive shaft 8 for a valve operation changes between a first angle α 1 and a second angle α 2 . The flow rate control in the temperature adjustment range mode gradually increases the flow rate Qa of the heated hot water while gradually decreasing the flow rate Qb of the bypass hot water, and the flow rate control in the flow rate adjustment range mode changes a total flow rate of hot water flowing through the valve device A so that the flow rate Qa of the heated hot water gradually decreases while the flow rate Qb of the bypass hot water is maintained at or below a predetermined minimum flow rate. When occurrence or risk of output of abnormally high-temperature hot water is detected, the rotation angle of the motor drive shaft 8 is set to the first angle α 1 in a case where the valve device A is in the temperature adjustment range mode, and set to the second angle α 2 in a case where the valve device A is in the flow rate adjustment range mode.

What is claimed is: 
     
         1 . A hot water apparatus, comprising:
 a water inlet passage and a hot water outlet passage respectively connected to an inlet side and an outlet side of a heat exchanger for hot water heating;   a bypass passage bypassing the heat exchanger to connect the water inlet passage and the hot water outlet passage to each other, and mixing hot water from the water inlet passage, as bypass hot water, with heated hot water flowing through the hot water outlet passage;   a valve device capable of changing a flow rate of the heated hot water flowing through the hot water outlet passage and a flow rate of the bypass hot water flowing through the bypass passage; and   an abnormality detection part capable of detecting occurrence or risk of output of abnormally high-temperature hot water in which hot water at a predetermined high temperature or above is output from the hot water outlet passage to exterior,   wherein the valve device is configured to be capable of sequentially executing flow rate control in a temperature adjustment range mode and flow rate control in a flow rate adjustment range mode in a process where a rotation angle of a motor drive shaft for a valve operation changes between a predetermined first angle and a second angle, wherein the flow rate control in the temperature adjustment range mode gradually increases the flow rate of the heated hot water while gradually decreasing the flow rate of the bypass hot water, and the flow rate control in the flow rate adjustment range mode changes a total flow rate of hot water flowing through the valve device so that the flow rate of the heated hot water gradually decreases while the flow rate of the bypass hot water is maintained at or below a predetermined minimum flow rate,   when occurrence or risk of output of abnormally high-temperature hot water is detected by the abnormality detection part, in a case where the valve device is in the temperature adjustment range mode, control is executed to set the rotation angle of the motor drive shaft to the first angle,   in a case where the valve device is in the flow rate adjustment range mode, control is executed to set the rotation angle of the motor drive shaft to the second angle.   
     
     
         2 . The hot water apparatus according to  claim 1 , wherein when occurrence or risk of output of abnormally high-temperature hot water is detected by the abnormality detection part, in a case where the valve device is at a boundary between the temperature adjustment range mode and the flow rate adjustment range mode,
 control is executed to set the rotation angle of the motor drive shaft to an angle among the first angle and the second angle on a side where an angle difference from the boundary is small.