If you experience technical problems with Lux thermostat, use a manual on this page – different models are covered. With the help of Lux thermostat troubleshooting guidelines, you will be able to reset and repair your home appliance properly. The tables contain the most common technical issues and instructions on how to solve them.
| Problem | Resolution |
|---|---|
| No fan function in heat mode | Move the switch on the back of the thermostat to its ELECTRIC POSITION for electric heat, or set the units fan control appropriately to ELECTRIC or another appropriate setting. |
| Fan On continuously | Move Fan switch from ON to Auto. |
| Remove the ”G” wire. If fan continues to run, then either the system is mis-wired, or the problem is in the system, not the thermostat. | |
| Indicates incorrect room temperature | Verify that your set temperature is what you expect it to be. The set temperature is always visible with “SET” on the display. |
| No second stage or AUX heating | The offset may be set to 0. This needs to be set to at least 1. |
| Emergency heat does not turn on | Place dip switch #1 located on the back of the thermostat to the ON position and press the HW_RST button. This will enable the second heating stage. Make sure there is a wire connected to the W2 terminal. |
| How do 1 set my thermostat to act as a manual thermostat? | Place dip switch #2 located on the back of the thermostat to the ON position and press the |
| How do 1 remove the programming? | HW_RST button. This will remove the programming features from your thermostat. |
| Heats or cools more than 5 degrees past its displayed set temperature | Remove thermostat body from the wall, leave the back plate in place. Verify that heating and cooling switch off within a few minutes. |
| Replace the units batteries with fresh Duracell or Energizer alkaline batteries. | |
| Set unit to heat mode. Adjust set temperature to at least 5 degrees below room temperature. Then adjust set temperature upward one degree at a time. Listen carefully for a soft click from the thermostat. This click should be heard near room temperature. |
| Problem | Resolution |
|---|---|
| If unsure how to connect your current wires | Contact our Technical Assistance Line or your HVAC service company. |
| Two wires control a heat only system | Connect one wire to W1 and the other to RH. |
| Two wires control a cool only system | Connect one wire to RC and the other to Y. |
| Two wires control heating AND cooling. | Currently no Lux controls are compatible with this system. |
| Three wires for forced air heat only system, where the previous thermostat did not have a clock or timer | The previous RH or RC wire is the 24-volt transformer wire. Connect it to RH. Leave jumper connecting RH to RC. Connect the forced air heat system to W1, and the fan wire to G. |
| Three wires control heating and cooling. One wire operates heat, one operates cooling and the third provides 24 VAC | Connect the 24-volt power wire to RH. Install a jumper connecting RH to RC. This jumper is usually pre-wired. Connect the heat wire to W1, and the cooling wire to Y. |
| Three wires control a cooling only system. One wire operates the compressor, one operates the fan and the third provides 24 VAC | Connect the 24-volt power wire to RC. Connect the cooling wire to Y and the fan wire to G. |
| Four wires control a heating and cooling, electric, gas or oil, forced air system that is NOT a heat pump | Connect the 24 VAC transformer wire to RH or RC. Install a jumper connecting RH to RC. This jumper is often prewired. Connect the heat wire to W1, the cooling wire to Y and the fan wire to G. |
| Four wires control a Single Stage Heat Pump. They were labeled: G, Y, R or RH or RC, and either B or 0 was used | Do not connect wires to both B and 0. Connect the reversing valve wire to B or 0, just as the previous thermostat. Install a jumper wire from RH to RC. Connect 24 VAC wire to RH too. Install a second jumper wire from W1 to Y. Connect compressor wire to Y and the fan wire to G. |
| Six or seven wires control a Heat Pump with an auxiliary heat stage. They were labeled: G, Y, R or RH or RC, and W or W2. Either B or 0 was used. And Emergency wire E is present. The C wire is common for 24 volt ac operation. | Do not connect wires to both 0 and B. Connect the reversing valve wire to 0 or B, just as the previous thermostat. Connect 24 VAC wire to RH and leave in the factory supplied jumper wire between RH and RC. Connect compressor wire to Y and fan wire to G. It is not necessary to wire the X, E or X2 terminal. Connect W or W2 to the W2 terminal and add a jumper wire from W1 to Y. If you have a C (common wire) connect it to the C terminal. Move dip switch #1 located on the back of the thermostat to the ON position. Set the GAS/ELECTRIC switch on the back of the thermostat to the ELECTRIC position. Once both of these changes have been made be sure to press the HW_RST button. |
| For further assistance: | Contact your HVAC service company or our Technical Assistance Line if not resolved. |
| Problem | Resolution |
|---|---|
| Display will not change | Peel protective plastic label from display. |
| Display blurred and unreadable | Peel protective plastic label from display. |
| Press the HW_RESET button on the back of your unit. | |
| Blank or fading display | Replace thermostat batteries with fresh AA size Duracell® or Energizer® alkaline batteries. Be sure that they are installed with their polarity (+ and -) correct. |
| Clean battery contacts with a pencil eraser and pry out the spring contact slightly to insure a clean, firm connection. | |
| Press the HW_RESET button on the back of your unit. | |
| Display is locked or will not respond | Check for a locked padlock icon on the display. |
| Touch the icon to see “UNLOCK KEYBOARD”. Touch “OK”. Press the UP and DOWN arrows to enter your lock code then touch “OK” when finished. To remove the lock with out your lock code, remove the thermostat from the wall and locate the button labeled HW RESET on the back of the thermostat. Press the HW RESET button down for 5 seconds then release. The padlock icon should now be in the unlocked position. You will need to reset the time on your thermostat. | |
| Displays reads “LO BATTERY” | Replace thermostat batteries with fresh AA size Duracell® or Energizer® alkaline batteries. Be sure that they are installed with their polarity (+ and -) correct. |
| Clean battery contacts with a pencil eraser and pry out the spring contact slightly to insure a clean, firm connection. | |
| What is the EMER button | The EMER setting is used with heat pump systems that have an emergency heat heating element. |
| Display reads “STG. 2” or “AUX” | “STG. 2” is displayed when the thermostat is turning on the first and second stages of a conventional heating system. “AUX” is displayed when the thermostat is turning on the first and auxiliary heating stages on a heat pump. |
| How do 1 set my thermostat to act as a manual thermostat? | Place dip switch #2 located on the back of the thermostat to the ON position and press the |
| How do 1 remove the programming? | HW_RST button. This will remove the programming features from your thermostat. |