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Reco-Boxx ZXR / ZXA / Flat – Operation and maintenance instructions
[03/
2022 ]
9.8 Type 8: Alarm indicating a T
o
sensor T1/T2/T3/T4 failure
• Conditions:
• Causes:
• One or more of the T° sensors T1/T2/T3/T4 connected to the TAC circuit and mounted on heat
exchanger is defect or not connected. These sensors are needed for the bypass control and the
anti-frost procedure.
• Effects:
Displayed on Touchpanel
Code
Text displayed
Level
T.10
Sensor T1 disconnected
3
T.11
Sensor T1 short circuit
3
T.20
Sensor T2 disconnected
3
T.21
Sensor T2 short circuit
3
T.30
Sensor T3 disconnected
3
T.31
Sensor T3 short circuit
3
T.40
Sensor T4 disconnected
3
T.41
Sensor T4 short circuit
3
TAC control board
ALARM OUTPUT
AL dPa OUTPUT
LED ALARM
Fans
Alarm Status
/
ON
Stopped
Manual reset mandatory.
9.9 Type 9: Alarm indicating failure on T° sensor T7
• Conditions:
• Only with water heating coil (IBA or EBA) option
• Causes:
• T° sensor T7 located on the coil and connected to the TAC circuit is defective (open or short cir-
cuit) or not connected.
This is used to prevent frosting of the internal or external heating coil. In this case, as a safety
measure, the 3-way valve is opened and the circulator contact is closed.
• Effects:
Displayed on Touchpanel
Code
Text displayed
Level
T.40
Sensor T4 disconnected
3
T.41
Sensor T4 short circuit
3
TAC control board
ALARM OUTPUT
AL dPa OUTPUT
LED ALARM
Fans
Alarm Status
/
ON
/
Manual reset mandatory.
