I have this same manufacturer, but the TR16. If yours is similar to mine (bi-directional) then it is likely that it uses a whole set of the X10 house codes, e.g. A1 through A16, or B1 through B16, etc. with lights on/off commands for setting the temp. My solution (not pretty!!) was to create a separate thermostat device for each on/off house code. Say 70 degrees is set with an "on" command to A1 and 71 degrees is set with an "off" command to A1, then I would create a thermostat device labeled A1 for those 2 temperaturs. 72 and 73 would fall under "on/off" for A2, etc.
I admit this is an ugly solution and if anyone has any other suggestions, it would be appreciated!