9-3-4.How To Diagnose By Error Code - Toshiba HWS-803XWHM3-E Service Manual

9-3-4. How to diagnose by error code
Defect mode detected by the water heat exchange
Diagnostic functional operation
Check
code
Operational cause
Pump or flowing quantity error
1) Detected by TC sensor
TC 63°C is detected in the heating or
hot water supply heat pump operation
(except for defrosting).
2) Detected by flow switch abnormality
When no signal of the flow switch is
showing 2 min after the built-in pump
operation started.
A01
3) Detection of chattering abnormality in
the flow switch input
Chattering detection: Detects input
changes (OFF⇔ON) 4 times within
10 seconds during operation.
4) Disconnection of the flow switch
connector
When the stopped built-in pump starts
its operation, the flow switch status is
detecting "water flow".
Temperature increase error (heating)
When one of the TWI, TWO and THO
A02
sensors exceeds 70°C.
Temperature increase error (hot water
supply)
A03
When the TTW sensor exceeds 85°C.
Antifreeze operation
1)TWO>20°C condition:
2×TC+TWO < -12°C is detected.
2)TWO 20°C condition:
TC+TWO < 4°C is detected.
3)TWI 10°C is detected during
A04
defrosting.
Piping antifreeze operation
Activating the heater under the condition
of TWO<4orTWI<4orTHO<4 does not
A05
achieve TWO,TWI,THO 5°C after 30
min elapsed.
Determination and action
Backup Automat
present ic reset
1. Almost no or little water flow.
• Not enough vent air
• Dirt clogging in the water piping
system.
• The water piping is too long.
• Installation of buffer tank and
×
×
secondary pump
1. Disconnection of the flow switch
connector.
2. Defect of the flow switch.
1. Check the water inlet, water outlet
Heating
×
and heater outlet (TWI, TWO, THO)
sensors.
O
Hot water
2. Defect of the backup heater (defect
O
automatic reset thermostat).
Heating
1. Check the hot water cylinder sensor
O (TTW).
O
Hot water 2. Check the hot water cylinder thermal
×
cut-out.
1. Almost no or little water flow.
• Dirt clogging in the water piping
system.
• The water piping is too long.
2. Check the heater power circuit.
×
• Power supply voltage, breaker,
O
power supply connection
3. Set the presence of the backup
heater.
4. Check the water inlet, water outlet
and heat exchange (TWI, TWO, TC)
sensors.
1. Check the heater power circuit.
• Power supply voltage, breaker,
power supply connection
O O
2. Check the water inlet, water outlet
and heater outlet sensors (TWI,.
TWO, THO).
3. Disconnection of the backup heater.
84
O ... Possible
× .... Not possible
Number of
abnormalities Detailed
for item
confirmation
4 91
2 91
4 91
2 91
1 92
1 93
Heating2
Hot water2 94
Cooling4
1 95