Issue
STR-250 is connected to a Xenta 102-AX and displays the space temperature but any attempts to modify the setpoint or override the occupancy is unsuccessful.
Environment
STR-250
Xenta 102-AX
Cause
The wiring between the Xenta 102-AX and the STR-250 must comply with the installation instructions:
18-24 AWG three conductor cable or shielded, twisted pair (Belden 9184 equivalent) 30 m (100ft) maximum from the controller. Total capacitance may not exceed 4000 pF.
Resolution
Ensure that the cabling matches the documented requirements.
Note: with lower gauge wiring the resistance increases and you might need to reduce the distance between the Xenta 102-AX and the STR-250 thermostat to ensure proper communication.