Four-way valve
EE 26
reversal failure
EEPROM data read
EE 27
malfunction
The inter-chip
communication
EE 28
failure on the main
control board
Inlet water
PP 01
temperature sensor
failure
Outlet water
PP 02
temperature sensor
failure
Heating piping
PP 03
sensor failure
Gas return sensor
PP 04
failure
Ambient
PP 05
temperature sensor
failure
Exhaust piping
PP 06
sensor failure
Antifreeze
PP 07
protection in
Winter
Low ambient
PP 08
temperature
protection
Piping temperature
PP 10
too high protection
under cooling mode
Water temperature
(T2) too low
PP 11
protection under
cooling mode
1. Four-way valve reversal failure
2. Lack of refrigerant (no detect
when T3 or T5 malfunction)
1. Wrong EEPROM data in the
program or failed input of EEPROM
data
2. Main board failure
Main board failure
1. The sensor failure or short circuit
2. The wiring of sensor is loose
1. The sensor failure or short circuit
2. The wiring of sensor is loose
1. The sensor failure or short circuit
2. The wiring of sensor is loose
1. The sensor failure or short circuit
2. The wiring of sensor is loose
1. The sensor failure or short circuit
2. The wiring of sensor is loose
1. The sensor failure or short circuit
2. The wiring of sensor is loose
Ambient temperature or water inlet
temperature is too low
1. Beyond
the
scope
environment
2. Sensor abnormality
1. Ambient temperature is too high
or the water temperature is too high
in cooling mode
2. Refrigeration system is abnormal
1. Low water flow
2. T2 temperature sensor abnormal
29
1. Switch to Cooling mode to check the
4-way valve if it has been reversed
correctly
2. Change a new 4-way valve
3. Fill with gas
1. Re-enter correct EEPROM data
2. Change a new main board
1. Turn off electricity supply and
restart it
2. Change a new main board
1. Re-fix the wiring of the sensors
2. Change the sensor
1. Re-fix the wiring of the sensors
2. Change the sensor
1. Re-fix the wiring of the sensors
2. Change the sensor
1. Re-fix the wiring of the sensors
2. Change the sensor
1. Re-fix the wiring of the sensors
2. Change the sensor
1. Re-fix the wiring of the sensors
2. Change the sensor
Normal protection
of
using
1. Stop using, beyond the scope of
using
2. Change the sensor
1. Check the scope of using
2. Check refrigeration system
1. Check water pump and waterway
system
2. Change T2 temperature sensor