Troubleshooting - Toshiba HWS-803XWHM3-E Data Book

7. HYDRO UNIT INSTALLATION MANUAL
12

TROUBLESHOOTING

„ Fault Symptoms
Symptom
Room is not heated or
cooled.
Water is not hot enough.
Nothing is displayed on the
remote controller.
Flow rate switch is
activated.
Error code [A01]
Hot water leaks from
pressure relief valve.
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
2) Detected by flow switch abnormality
A01
3) Detection of chattering abnormality
in the flow switch input
4) Disconnection of the flow switch
connector
Temperature increase error
(heating)
A02
(TWI, TWO, THO)
Temperature increase error (hot
water supply)
A03
(TTW)
Possible cause
Incorrect remote controller setting
Incorrect function code setting
Backup heater disconnected
Insufficient capacity
Sensor defect
Power is not supplied.
Incorrect setting
Air bite in the pump
Low hydraulic pressure
Strainer is clogged.
Large resistance on the hydro side
Malfunction of motorized 3-way valve
for hot water supply
Excessive hydraulic pressure
Insufficient capacity of expansion tank
Expansion tank failure
Backup
present
63°C)
u
Heating
O
Hot water
u
Heating
O
Hot water
u
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 DIP switch setting on the Hydro Unit board.
Check the setting with the function code table.
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.
Automatic
reset
1. Almost no or little water flow.
• Not enough vent air
• Dirt clogging in the water piping system.
u
• 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 and heater outlet
(TWI, TWO, THO) sensors.
O
2.Defect of the backup heater (defect automatic reset
thermostat).
1. Check the hot water cylinder sensor (TTW).
O
2. Check the hot water cylinder thermal cut-out.
– 125 –
Engineering Data Book
O ... Possible
× .... Not possible
Determination and action