The Lux 500 is a digital programmable thermostat that allows you to control your furnace or air conditioning unit to ensure that indoor temperatures are favorable for your entire family. An improperly functioning thermostat can limit energy efficiency, so common problems such as low batteries and incorrect settings must be corrected. Maximize heating and cooling efficiency with a few thermostat troubleshooting procedures.

Step 1

Turn off your thermostat if you see a "low bat" warning flashing on your thermostat's screen.

Step 2

Open the battery compartment on the side of the thermostat and remove the old batteries. If the battery contacts inside the thermostat are dirty, clean them with a lint-free cloth. Dirty contacts can cause short circuits. Insert two new AA alkaline batteries and replace the cover. Turn on your thermostat.

Step 3

Open the door on the bottom of your thermostat if your furnace or air conditioner is not turning on. Move the switch on the far right side to "Heat" or "Cool."

Step 4

Open the door on the bottom of your thermostat if you do not hear the furnace or air conditioner blower. Locate the switch labeled "FAN" and make sure it is in the "ON" or "AUTO" position. If the switch is in the "ON" position, the fan will run all the time. If the switch is in the "AUTO" position, the fan will cycle on and off when the compressor is on or off.