Toshiba HWS-1501CSHM3-E(-UK), HWS-802XWHT6-E, HWS-802H-E, HWS-802XWHM3-E, HWS-3001CSHM3-E(-UK)

[A02] Error Temperature rise and error short circuit

Start

TWI, TWO, and THO

sensor characteristics are correct

Yes

(TWI,TWO,THO 70°C)

No

Replace TWI, TWO, and THO sensors

Flow switch is normal	No
Yes
Water outlet	No
temperature is 70°C
or higher
Yes
Hot water from	Yes
boiler or other circuits does
not come in
No

Replace flow switch

Correct water circuit (To prevent hot water of

other circuits from entering)

Backup heater is energized

Yes

Failure of backup heater (Too large heater input, thermostat short circuit)

(Measure heater current) No

Replace water heat exchange control board

Replace heater unit

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