Technical data
11.2 Thermostat T-55 alarms/problems
An alarm is sent when more than 3 hours have elapsed since the controller received the last radio signal from the thermostat.
The table below lists problems that can occur in Thermostat T-55.
Indication Causes Solutions
LED fl ashes twice Thermostat battery power is running low Replace batteries
11.3  Thermostat T-54 Public alarms/problems
An alarm is sent when more than 3 hours have elapsed since the controller received the last radio signal from the thermostat.
The table below shows problems that can occur in Thermostat T-54 Public.
Indication Causes Solutions
Power LED and channel LED fl ashes Cover of thermostat is opened Check thermostat settings and replace 
thermostat cover
LED fl ashes twice Thermostat battery power is running low Replace the batteries
11.4  Controller C-55/56 alarms/problems
An alarm is sent when more than 3 hours have elapsed since the controller received the last radio signal from the thermostat.
The table below shows problems that can occur in the Controller C-55/56.
Indication Causes Solutions
Power LED and channel LEDs in the 
Controller C-55/56 fl ash
Antenna out of position or wire 
disconnected
Install antenna in correct position with wire 
correctly connected
Alarm in Interface I-75/76 
Battery icon 
 displayed in room 
information on Interface I-75/76
Batteries in thermostat are discharged Replace batteries
When error is resolved, thermostat screen 
displays room temperature and battery icon 
is replaced with 
Radio alarm in Interface I-75/76 
Radio icon 
 in room information on 
Interface I-75/76 
Power LED and thermostat LED's in 
the Controller C-55/56 for connected 
channels fl ash
Thermostat is out of correct position Reduce distance between thermostat and 
Controller C-55/56 or change location of 
thermostat in the room
11.5 Contact installer
For installer contact information, see the installation report in the fold-out of this document. Prepare the following information before 
contacting an installer:
• Installation report
•  Drawings of the underfl oor heating system (if available)
•  List of all alarms, including time and date
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UPONOR CONTROL SYSTEM – INSTALLATION AND OPERATION MANUAL
UK English










