Toshiba HWS-802XWHM3-E Service Manual page 77

[A03] Error Temperature rise and error short circuit
Start
TTW sensor
characteristic is correct
Hot water cylinder heater
is energized
Mg-sw (RY05) for
heater operates
At normal
temperature, tank thermostat
is energized
Hot water cylinder
thermostat operates
Replace water heat exchange control board
(TTW 85°C is detected)
No
Yes
No
Yes
No
Yes
No
Yes
No
Operation
temperature 82°C
Yes
Operating noise at normal time
76
Replace TTW sensor
Replace Mg-sw
Replace hot water
cylinder thermostat