HTW VAW 2 - Malfunctioning of the Unit and Error Codes

Malfunctioning of the unit and error codes
When an error occurs or the protection mode is set automatically, the circuit board and the
wired controller will both display the error message.
Protection/
Malfunction
Error
code
LED
indicator
Possible reasons Corrective actions
Standby Dark
Normal
running
Bright
P1
1) The sensor open
1) Check the sensor
connection
2) Replace the sensor
3) change the PCB board
Lower tank
☆●
circuit
water temp.
(1flash 1
2) The sensor short
sensor failure
dark)
circuit
3) PCB board failure
P2
1) The sensor open
1) Check the sensor
connection
2) Replace the sensor
3) change the PCB board
Upper tank
☆☆●
circuit
water temp.
(2 flashes 1
2) The sensor short
sensor failure
dark)
circuit
3) PCB board failure
P3
1) The sensor open
circuit
2) The sensor short
circuit
3) PCB board failure
1) Check the sensor
connection
2) Replace the sensor
3) change the PCB board
Evaporator ☆☆☆●
coil temp. (3 flashes 1
sensor failure dark)
P4
1) The sensor open
1) Check the sensor
connection
2) Replace the sensor
3) change the PCB board
Return air
☆☆☆☆●
circuit
temp sensor
(4 flashes 1
2) The sensor short
failure
dark)
circuit
3) PCB board failure
Ambient P5 ☆☆☆☆☆ 1) The sensor open 1) Check the sensor
C
Evaporator coil temp. sensor
detect range
-9 ~ 99°C
Actual testing value. Error code P3
will be shown in case of a malfunction
D
Return gas temp. sensor
detect range
-9 ~ 99°C
Actual testing value. Error code
PP4 will be shown in case of a
malfunction
E
Ambient temp. sensor
detect range
-9 ~ 99°C
Actual testing value. Error code
PP5 will be shown in case of a
malfunction
F
Electronic expansion valve
step
-9 ~ 99°C
N*10 step
H
Temp of solar thermal
collector
0-140℃
Measured value，if failure，show P6
87
A
Inlet water temp.
sensor detect range
-9 ~ 99°C
Actual testing value. Error code P1 will
be shown in case of a malfunction
B
Outlet water temp.
sensor detect range
-9 ~ 99°C
Actual testing value. Error code P2 will
be shown in case of a malfunction
P
Output voltage of electrical
anode
0-5
Actual=display value x 10