Toshiba HWS-802XWHT6-E - Manual (Page 78)

77
Toshiba
[A04] Error Freeze prevention control
When the outside temperature or inlet water temperature is low (approx. 20°C or lower) and the room load is large
(operation frequency rating), the freeze prevention control may be activated.
Excess air
inside pump
Secure water
circulation amount
Circulation
flow shortage
Dirt clogging
inside water circuit
12 M or longer
water pipe to
a branch, or 5 or
less branches Fit buffer tank and the
second pump
Set DP_SW11-1 to ON
No
No
No
No
(inside strainer, etc)
Chattering from
flow switch
Water heat
exchanger board DP_SW11-1
is ON
Power is
connect to backup
heater terminal
Backup
heater terminal has
230ACV ( ± 23V)
Start
Operation restart
Replace water heat
exchange control board
Perform
air vent
Set heater breaker to ON
Check indoor wiring
Replace flow switch
No
Yes
Yes
Yes
Yes
Replace backup heater unit
No
(Backup heater NG)
(See Characteristic table on page 101)
Backup
heater element
is conductive
Yes
Replace TC, TWO,
and TWI sensors No
TC, TWO, TWI
sensor characteristics
are correct
Yes
Connect backup heater
power cable
Yes
+00A09-002_01EN_SVM_ALL_Air_to_Water.book Page 77 Monday, October 5, 2009 2:09 PM