How did you remove the thermostat? If you did it in Connected Sensors, then you simply removed it from the Almond+, but you didn't reset the thermostat.
Go into Add Sensor, tap on Remove and then join the thermostat and it'll reset. Then Add and join the thermostat again and it'll connect.
The sliders are a bit odd, but it's actually the thermostat that controls them and it'll jump, but then it should go to the correct temperature. We've change the UI in the most recent version of the Android app and we're working on doing the same for the other UI's.