Hot water supply device

Abstract

A controller, based on a comparison between an operation parameter of a hot water supply device and a determination value, executes position reset of a stepping motor which is a drive source of a valve. During execution of the position reset, when a control value of a rotational position is initialized according to a detection signal generated when the rotational position reaches a reference position, if the magnitude of an error between the control value before initialization and the reference position is larger than a reference range, the determination value is changed so that an execution frequency of the position reset increases.

1 . A hot water supply device, comprising:
 a control valve, arranged in a flow path of a fluid, having an opening degree controlled with a stepping motor as a drive source; and   a controller, controlling a rotational position of the stepping motor to control the opening degree of the control valve, wherein   the stepping motor is configured to output a detection signal to the controller when the rotational position reaches a predetermined reference position, and   the controller, based on a comparison between an operation parameter of the hot water supply device and a determination value, executes rotational position initialization processing by continuously generating a control signal to drive the rotational position of the stepping motor to the reference position until receiving the detection signal from the stepping motor, and, during execution of the rotational position initialization processing, upon receiving the detection signal, initializes a control value of the rotational position to a value corresponding to the reference position, and, when an absolute value of an error between the control value before initialization and the reference position is outside and larger than a predetermined reference range, changes the determination value so that an execution frequency of the rotational position initialization processing increases.   
     
     
         2 . The hot water supply device according to  claim 1 , wherein
 the controller, when changing the determination value to increase the execution frequency, limits the execution frequency not to be higher than a predetermined upper limit and changes the determination value.   
     
     
         3 . The hot water supply device according to  claim 1 , wherein,
 when the absolute value of the error at receipt of the detection signal during execution of the rotational position initialization processing is outside and smaller than the reference range, the controller changes the determination value so that the execution frequency of the rotational position initialization processing decreases.   
     
     
         4 . The hot water supply device according to  claim 3 , wherein
 the controller, when changing the determination value to decrease the execution frequency, limits the execution frequency not to be lower than a predetermined lower limit and changes the determination value.   
     
     
         5 . The hot water supply device according to  claim 1 , further comprising:
 a heating mechanism, heating at least a portion of the fluid flowing through the flow path where the control valve is arranged, wherein   the operation parameter comprises one of number of operations or operation time of the heating mechanism, number of changes in the opening degree of the control valve, and a time elapsed since a previous execution timing of the rotational position initialization processing.