Troubleshooting - Toshiba HWT-601F21SM3W-E Installation Manual

Hydro Unit
11

Troubleshooting

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Fault symptoms
Symptom Possible cause
Incorrect remote controller setting
Incorrect function code setting
Room is not heated or
cooled.
Backup heater disconnected
Water is not hot enough.
Insufficient capacity
Sensor defect
Power is not supplied.
Nothing is displayed on the
remote controller.
Incorrect setting
Air bite in the pump
Low hydraulic pressure
Almost no or little water
flow.
Strainer is clogged.
Error code [A01]
Large resistance on the hydro side
Malfunction of motorized 3-way valve
for hot water supply
Excessive hydraulic pressure
Hot water leaks from
overpressure preventive
valve. Insufficient capacity of expansion tank
Expansion tank failure
Pump lock. Pump lock due to clogging of dust.
Error code [A14]
65-EN
Corrective action
Check remote controller operation and temperature
setting
Check function code setting with the function code table.
Check backup heater and bimetal thermostat.
Check selection of equipment.
Check whether temperature sensor is installed at the
normal position.
Check power supply wiring.
Check the setting with the DN codes.
Release air completely according to the procedure.
Set hydraulic pressure considering pipe height, and
replenish water until manometer shows a value of set
hydraulic pressure or more.
Clean the strainer.
Widen water path to the Hydro Unit or adopt a bypass
valve.
Check wiring and parts.
Set hydraulic pressure considering pipe height, and
replenish water until manometer shows a value of set
hydraulic pressure or more.
Check expansion tank capacity compared to total water
amount. If it is insufficient, install another expansion
tank.
Check the air pressure.
Insert a Phillips screwdriver into the hole and turn to the
left or right to unlock.
hole
– 33 –
Defect mode detected by the Hydro Unit
Please don't continue backup operation in a state of displaying a check code.
Remove the cause of the anomaly immediately.
Diagnostic functional operation
Check
code
Operational cause
Pump or flowing quantity error
A01
Detected by flow rate abnormality
Temperature increase error
(heating)
A02
(TWI, TWO, THO)
Temperature increase error (hot
water supply)
A03
(TTW)
Antifreeze operation
A04
Piping antifreeze operation
A05
Low pressure sensor operation
error
A08
Overheat protection operation
(Thermostat of the backup heater)
A09
Antifreeze operation 2
A10
Operation of the release protection
A11
Determination and action
Backup Automatic
operation 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. Check the water inlet, water outlet and heater outlet
(TWI, TWO, THO) sensors.
×
O
2.Defect of the backup heater (defect automatic
reset thermostat).
Heating
O
1. Check the hot water cylinder sensor (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 or too short.
2. Check the heater power circuit.
×
O • Power supply voltage, breaker, 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 and flow sensor.
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.
1. Almost no or little water flow.
2. Defect of the flow sensor.
3. On-load cooling or prolonged defrosting (a lot of frost
×
O
formation) under the above conditions.
4. Defect in the low pressure sensor.
5. Check the refrigeration cycle (gas leak).
1. No water (heating without water) or no water flow.
2. Defect of the flow sensor.
× ×
3. Defect of the backup heater (poor automatic reset
thermostat).
Heating
1. Almost no or little water flow.
×
×
2. Check the water inlet, water outlet and heat exchange
Hot water
(TWO, TC) sensors.
O
Heating
1. Almost no water flow.
×
×
2. Defect of the flow sensor.
Hot water
3. Check the water outlet temperature sensor (TWO).
O
Installation Manual
O ....Possible
×
.....Not possible
66-EN