Toshiba HWS-P805XWHM3-E - Page 87

86
[A05] Error Piping freeze prevention control
Water heat
exchange control board
DPSW11-1 is ON
Replace backup heater
and safety valve
Set water heat board
DPSW11-1 to ON
No
(Backup heater NG)
Backup heater terminal
has 220-230 V (± 10 %)
Power is connect to
built-in heater terminal
Yes
Yes
Restart
TWI 4, TWO 4, or
THO 4 is detected
Circulation pump keeps
being energized or 3 minutes
passed after the start
No
No
Place power cable for
backup heater
Set breaker for backup heater
to ON, or Check hydro
electronic wiring
No
Backup heater element
is conductive
Yes
Replace TWI, TWO,
and THO sensors
No
TWI, TWO, THO
sensor characteristics
are correct
Yes
Yes
Replace water heat
exchange control board
(Refer to Characteristic table on page 113)