Toshiba HWS-1402XWHT9-E, HWS-802XWHT6-E, HWS-802H-E Diagnostic functional operation Number

	Diagnostic functional operation				Number of
Check				Determination and action	abnormalities	Detailed
code		Backup	Automat		for	item
	Operational cause
		present	ic reset		confirmation
	Pressure switch operation			1. Almost no or little water flow.
	The pressure switch operates for 300			2. Defect of the flow switch.
A07	sec continuously during the heat pump	O	×	3. On-load operation under the above	1	79
	operation.			conditions.
				4. Defect in the pressure switch.
	Low pressure sensor operation error			1. Almost no or little water flow.
	The low pressure sensor detected 0.2			2. Defect of the flow switch.
A08	MPa or less.	O	×	3. On-load cooling or prolonged	8	80
				defrosting (a lot of frost formation)
				under the above conditions.
				4. Defect in the low pressure sensor.	2
	Overheat protection operation			1. No water (heating without water) or
	When the thermostat of the backup			no water flow.	2
A09	heater activates during the operation of	O	×	2. Defect of the flow switch.		81
	the heat pump or backup heater.
	When the thermostat operation is			3. Defect of the backup heater (poor	1
				automatic reset thermostat).
	activated while it has been stopped.
	Operation of the release protection	Heating		1. Almost no water flow.
	When the TWO release counts to 10.	Cooling
				2. Defect of the flow switch.
A11		×	×		10	82
				3. Check the water outlet temperature
		Hot water
				sensor (TWO).
		O
	Heating, hot water heater			1. Activated by a large load of heating
	The antifreeze control is detected under			or hot water supply.
	the condition of TWI<20°C while			2. Check the heater power circuit
A12	TWI>15°C, TTW>20°C is not detected	O	O	(backup or hot water cylinder	1	83
	after the heater backup.			heater).
				• Power supply voltage, breaker,
				power supply connection
	Regular communication error
	between hydro unit and remote
E03	controller	×	O	1. Check remote control connection.	1	—
	When there is no regular communication			2. Defect in the remote control.
	from the remote control for 3 min, or
	when no remote control is equipped.
	Regular communication error			1. Check the serial circuit.
E04	between hydro unit and outdoor unit	O	O	• Miswiring of the crossover between	1	84
	The serial signal cannot be received			the water heat exchanger and the
	from outdoor.			outdoor unit
	TC sensor error			1. Check the resistance value and
F03	Open or short circuit in the heat	O	O	connection of the heat exchange	1	85
	exchange temperature sensor.			temperature sensor (TC).
	TWI sensor error			1. Check the resistance value and
F10	Open or short circuit in the water inlet	O	O	connection of the water inlet	1	86
	temperature sensor.			temperature sensor (TWI).
	TWO sensor error			1. Check the resistance value and
F11	Open or short circuit in the water outlet	×	O	connection of the water outlet	1	87
	temperature sensor.			temperature sensor (TWO).
	TTW sensor error			1. Check the resistance value and
F14	Open or short circuit in the hot water	×	O	connection of the hot water cylinder	1	87
	cylinder sensor.			sensor (TTW).

68