Toshiba ESTIA HWS-1501CSHM3-E, Service Manual

Page: 86 / 212

85
A07
Pressure switch operation
The pressure switch operates for 300
sec continuously during the heat pump
operation.
O
×
1. Almost no or little water flow.
2. Defect of the flow switch.
3. On-load operation under the above
conditions.
4. Defect in the pressure switch.
1 96
A08
Low pressure sensor operation error
The low pressure sensor detected 0.2
MPa or less.
O
×
1. Almost no or little water flow.
2. Defect of the flow switch.
3. On-load cooling or prolonged
defrosting (a lot of frost formation)
under the above conditions.
8
97
4. Defect in the low pressure sensor. 2
A09
Overheat protection operation
When the thermostat of the backup
heater activates during the operation of
the heat pump or backup heater.
When the thermostat operation is
activated while it has been stopped.
O
×
1. No water (heating without water) or
no water flow.
2. Defect of the flow switch.
2
98
3. Defect of the backup heater (poor
automatic reset thermostat).
1
A11
Operation of the release protection
When the TWO release counts to 10.
Heating
Cooling
×
Hot water
O
×
1. Almost no water flow.
2. Defect of the flow switch.
3. Check the water outlet temperature
sensor (TWO).
10 99
A12
Heating, hot water heater
The antifreeze control is detected under
the condition of TWI<20°C while
TWI>15°C, TTW>20°C is not detected
after the heater backup.
O O
1. Activated by a large load of heating
or hot water supply.
2. Check the heater power circuit
(backup or hot water cylinder
heater).
• Power supply voltage, breaker,
power supply connection
1 100
E03
Regular communication error
between hydro unit and remote
controller
When there is no regular communication
from the remote control for 3 min, or
when no remote control is equipped.
×
O
1. Check remote control connection.
2. Defect in the remote control.
1 —
E04
Regular communication error
between hydro unit and outdoor unit
The serial signal cannot be received
from outdoor.
O O
1. Check the serial circuit.
• Miswiring of the crossover between
the water heat exchanger and the
outdoor unit
1 101
F03
TC sensor error
Open or short circuit in the heat
exchange temperature sensor.
O O
1. Check the resistance value and
connection of the heat exchange
temperature sensor (TC). 1 101
F10
TWI sensor error
Open or short circuit in the water inlet
temperature sensor.
O O
1. Check the resistance value and
connection of the water inlet
temperature sensor (TWI). 1 103
F11
TWO sensor error
Open or short circuit in the water outlet
temperature sensor.
×
O
1. Check the resistance value and
connection of the water outlet
temperature sensor (TWO). 1 103
F14
TTW sensor error
Open or short circuit in the hot water
cylinder sensor.
×
O
1. Check the resistance value and
connection of the hot water cylinder
sensor (TTW). 1 104
Check
code
Diagnostic functional operation
Determination and action
Number of
abnormalities
for
confirmation
Detailed
item
Operational cause
Backup
present Automat
ic reset