Hydro Unit
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 [P01]
Hot water leaks from
pressure relief valve.
Alarm
Alarm description and generation/reset conditions
indication
Regular communication error between hydro unit and remote controller (system controller)
If there is no regular communication from the remote controller for three minutes, the hydro unit regards it as no
E03
remote controller. If there is no communication from both sides, alarm E03 occurs.
Auto-reset: When successful regular communication is made
Regular communication error between hydro unit and outdoor unit
When serial signal from the outdoor unit cannot be received though normal serial signal is sent to the outdoor
unit
1) When serial signal cannot be received continuously for 60 seconds (S code communication)
E04
2) Communication is still not successful for 80 seconds through three retries if serial signal cannot be
received for 20 seconds after new communication (f code) starts
When the remote controller starts operation, serial transmission starts with the new communication format.
Auto-reset: When successful regular communication is made
Condensing temperature TC sensor defect
F03
If short-circuit or open-circuit state continues for two seconds, an alarm occurs.
Auto-reset: When normal value is confirmed
Hydraulic heat exchanger inlet temperature TWI sensor defect
F10
If short-circuit or open-circuit state continues for two seconds, an alarm occurs.
Auto-reset: When normal value is confirmed
Hydraulic heat exchanger outlet temperature TWO sensor defect
F11
If short-circuit or open-circuit state continues for two seconds, an alarm occurs.
Auto-reset: When normal value is confirmed
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
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.
– 41 –
Installation Manual
EN
40-EN