A Lite thermostat blinks red when I try to associate it

If a wireless Lite thermostat blinks red when you try to associate it, it means that there is already another Lite thermostat in that zone. You should select a different zone number.

If there is no Lite thermostat in that zone, the association process may have failed and the system is detecting a zone that is no longer in the system. You must restart the entire system to resolve this issue (How do I reset the entire system?).