To troubleshoot a locked Lux thermostat, you need to acquire a lock code. The lock code is then entered into the system using a specific set of steps that allows you to reset the thermostat, according to LuxProProducts.com.
The first step to entering the lock code is to hold down the next button for at least 2 seconds. Enter the lock code into the system by pressing next until the desired digit is displayed. Once the code is entered, press the next button again until the default screen is displayed. If you are unable to acquire a lock code, you must press the reset button. Within the next 4 seconds, you must press the up button three times and the down button once. Following these steps to reset the thermostat, the lock code becomes 0000.
Resetting the lock code allows you to override the system and reprogram the thermostat to your preferred specifications. You are able to override the system at any time by raising or lowering the set temperature. To remove all programming from the system and use the thermostat manually at all times, change the jumper JP1 that is on the back of thermostat to up and press the reset button.