Toshiba ESTIA R32 HWT-401HW-E Manual page 82

Fault detection via water-to-air heat exchanger or outdoor unit
Error
Code
Technical cause
Pump or flow volume error
1. Determined by TC sensor
TC≥63°C was detected in heating or hot
water supply heat pump operation
(except for defrosting)
2. Detected by flow switch deviation
In no signal from the flow switch is
displayed 2 minutes after the installed
pump starts
A01
3. Detection of excessive rattling at the flow
switch input
Detection of rattling:
Detects changes at the input (OFF
4 times within 10 seconds during operation
4. Removal of the flow switch connection
If the stopped installed pump starts
operation, the flow switch status "Water
flow" is detected
Water temperature increase error
(heating)
A02
If one of the TWI, TWO, and THO sensors
reaches 70°C
Temperature increase error
A03 (hot water preparation)
If the TTW sensor reaches 85°C
Frost protection mode (1)
1. TWO>20°C:
2xTC+TWO≤-12°C detected
A04
2. TWO≤20°C:
TC+TWO≤4°C detected
3. TWI≤10°C detected during defrosting
Piping frost protection mode
Activation of the heating if TWO<4 or TWI<4
A05
or THO<4 and after 30 minutes not TWO,
TWI, THO≥5°C
Pressure switch operation
The pressure switch works continuously
A07
for 300 seconds while the heat pump is in
operation
Combined fault
A07
HI POWER Model name of the Hydrobox is different
42 I 42 I TOSHIBA
TOSHIBA
Diagnostics of functional operation
Backup
present
Heating
Hot water
ON)

Heating
Hot water
Heating
Hot water
O ........ Possible
X ........ Not possible
Automatic
reset
Hardly any or low water flow rate
- Insufficient air supply
- Blockage due to dirt in water pipe system
- The water pipe is too long
- Installation of a buffer tank and a secondary
X
pump
X
O
1. Removal of the flow switch connection
2. Flow switch defect
1. Check water inlet, water outlet, and heating
X outlet sensors (TWI, TWO, THO)
O
2. Backup heater defect
O (defective thermostat for automatic reset)
O 1. Check the hot water cylinder sensor (TTW)
O
2. Check the hot water cylinder thermo cut-out
X
1. Hardly any or low water flow rate
- Blockage due to dirt in water pipe system
- The water pipe is too long or short
2. Check the heating circuit
O X - Power supply voltage, cut-out, power supply
connection
3. Apply the setting for the backup heater
4. Check water inlet, water outlet, heat exchanger
sensors (TWI, TWO, TC), and flow switch
1. Check the heating circuit
- Power supply voltage, cut-out, power supply
connection
O O
2. Check water inlet, water outlet, and heating
outlet sensors (TWI, TWO, THO)
3. Disconnection of the backup heater
1. Hardly any or low water flow rate
2. Flow switch defect
O X
3. Under-load operation under the above conditions
4. Pressure switch defect
O X Check whether DP_SW13_4 is set to "ON"
Determination and measures