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» Support LP0511D

Troubleshooting Poor Temperature Regulation
• This page lists problems that may affect the temperature performance of your LUX thermostat with suggested resolutions.
• For more detailed information please refer to the instructions that came with your thermostat.
The instruction manual for this model can be viewed in PDF format by clicking here.
 
Model LP0511D
   
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 Refer to thermostat manual to verify that your set temperature is what you expect it to be. The set temperature is always visible with "SET" on the display.
How do I set my thermostat to act as a manual thermostat? How do I remove the programming? Place jumper JP1 located on the back of the thermostat to the UP position and press the RESET 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 unit's 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.
Refer to your unit's manual to decrease the unit's swing setting to a narrower setting.
Verify that your unit's placement and mounting are optimum per the installation section of its manual. 
Refer to the wiring troubleshooting guide to verify that your thermostat is wired correctly. Insure you are using the correct wiring diagram for your heating/cooling system.
Note that in Cool Mode the thermostat may not activate a cooling stage until its compressor protection time has elapsed this may be a long as 5 minutes.
  Where the wires are coming out of the wall fill the hole with non-combustible insulation or putty to prevent drafts from affecting the thermostats performance.
No heat or cooling when expected If using with a heat pump be sure to adjust the jumpers located on the back of the thermostat for heat pump mode. JP4 should be set to the UP position. Also make sure the fan jumper, JP5, is in the ELECTRIC position. You will need to reset your thermostat after you make these changes. 
Refer to thermostat manual to verify that your set temperature is what you expect it to be. The set temperature is always visible with "SET" below.
Replace the batteries with fresh Duracell® or Energizer® alkaline batteries. Press reset with small Phillips screw driver. It may be necessary to reconfigure some settings after a reset.
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. Adjust set temperature down one degree at a time. Again listen carefully for a soft click from the thermostat near room temperature. 
Refer to wiring to verify that it is according to the wiring diagram applicable to your system.
If your system is a low voltage system having 24VAC or less, and you are technically inclined, you may jump terminals as given below out to detect a malfunction in your system. 
Fan Test With the power ON at the fuse box, touch the "G" wire to the "RH" terminal. The fan should come on immediately and stay on. The rush of air is usually heard.
If the fan does not come on it is an indication that there is a problem with your system. Check any breaker or fuses that feed the 24VAC transformer that powers your system.
Heat Test To test gas or oil heating systems, take the "W" wire off its terminal. With the power ON at the fuse box, touch the "W" wire to the "RH" terminal for a couple of minutes and the heater should come on and stay on until the wire is removed.
Cooling Test To test cooling, remove the "G" and "Y" wires. Connect them together with the "RC" for several minutes to observe operation. The system should come on and stay on. If the cooling fails to come on, or comes on and off, the problem is in the system.
Heat Pump Test To test a heat pump system with an "O" wire, three wires must be connected together with the power terminal. The power terminal is "RH". With the power ON at the fuse box, connect the "O"  and "Y", and "G" wires to the "RH" terminal for a couple of minutes and the unit should provide cool air. Wait at least 5 minutes and repeat this test without the "O" wire. The unit should provide Heat.  
To test a heat pump system with a "B" wire, three wires must be connected together with the power terminal. The power terminal is "RH". With the power ON at the fuse box, connect the "B" and "Y" and "G" wires to the "RH" terminal for a couple of minutes and the unit should provide warm air.  Wait at least 5 minutes and repeat this test without the "B" wire. The unit should provide cool air.  
For further assistance: Contact your HVAC service company or our Technical Assistance Line if not resolved.
 
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