There are two key things you need to make sure you have done.
Firstly, the Telemetry1 board temperature monitoring feature is part of the voltage monitoring circuit. This means you must have a voltage applied to the DC IN port for this to work (24VDC or lower). This is documented in the Telemetry1 manual.
Secondly, for the TransPort to communicate with this circuit The ASY 1 (Serial port 1) must be set to 9600 baud. You can do this via the web interface under:
Configuration - Network > Interfaces > Serial > Serial Port 1
You must then save ALL and reboot. If you don't save ALL the serial settings will not be saved. You must also reboot as serial settings are loaded only at start up.
This should then work.