Symptom
Cause
Water flowing sound during operation.
Refrigerant flow inside the unit
Operation is delayed a few minutes after restarting
The delay is a protection for the compressor.
Outdoor unit emits water/steam.
Condensation or evaporation occurring in the pipes.
Steam comes out of the outdoor unit in the heating mode.
It is caused by defrost operation in the heat exchanger.
Outdoor unit does not operate.
It is caused by the protection control of the system when outdoor
temperature is out of the operating range.
System operation switches off.
It is caused by the protection control of the system. When the
water inlet temperature is lower than 10°C, the compressor stops
and the backup heater power turns on.
System is hard to heat up.
When the panel and the floor are heated simultaneously, warm
water temperature may decrease, which may reduce the heating
ability of the system.
When the outdoor air temperature is low, the system may need
longer time to heat up.
Discharge outlet or intake inlet in the outdoor unit is blocked by
some obstacle, such as a pile of snow.
When the pre-set water outlet temperature is low, the system may
need longer time to heat up.
System does not heat up instantly.
System will take some time to heat up the water if it starts to
operate at cold water temperature.
Backup heater is automatically turned ON when it is
disabled.
It is caused by the protection control of the indoor unit heat
exchanger.
Operation starts automatically when the timer is not set.
Sterilisation timer has been set.
Loud refrigerant noise continues for several minutes.
It is caused by protection control during device operation at
outdoor ambient temperature lower than -10°C.
*1
COOL mode is unavailable
System has locked to operate in HEAT mode only.
Symptom
Check
Operation in HEAT/
*1
COOL mode is not working efficiently.
Set the temperature correctly.
Close the panel heater/cooler valve.
Clear any obstruction in the air inlet and air outlet vents of the
outdoor unit.
Noisy during operation.
Outdoor unit or indoor unit has been installed at an incline.
Close the cover properly.
System does not work.
Circuit breaker has tripped/activated.
Operation LED is not lit or nothing is displayed on the
Remote Controller
Power supply is working correctly, or a power failure has occurred.
*1 The system is locked to operate without COOL mode. It can be unlocked only by authorised installers or our authorised service
partners.
*2 Only displayed when COOL mode is unlocked (This means when COOL mode is available).
Check the following before calling for servicing.
Troubleshooting
18
