Lennox ComfortSense L5732U User Manual (English)

Questions and Answers:

B
brianelliottAug 21, 2025
What to do if Lennox Thermostat heating system does not turn on?
- J
  Jeremy VaughnAug 21, 2025
  If your Lennox thermostat's heating system isn't turning on, try these steps: * Ensure the SYSTEM key is set to heat. * Verify the heat temperature setting is above the room temperature and "Heat On" is displayed. * Check the circuit breaker and the power switch for the heating/cooling system. * Confirm the furnace door is securely closed. Allow five minutes for the heating system to respond. If the issue persists, consider contacting a qualified service technician.
A
Amber IbarraAug 22, 2025
What to do if Lennox Thermostat cooling system does not turn on?
- A
  Aaron WilliamsAug 22, 2025
  If the cooling system on your Lennox thermostat isn't turning on: * Press the SYSTEM key to set it to Cool. * Make sure the cooling temperature is set below the room temperature, and "Cool On" is displayed. * Check the circuit breaker and the power switch for the heating/cooling system. * Ensure the furnace door is securely closed. Allow five minutes for the cooling system to respond. If the problem continues, contact a qualified service technician.
C
Catherine MccormickAug 25, 2025
How to unlock Lennox ComfortSense L5732U Thermostat touch screen?
- P
  Patricia MayoAug 25, 2025
  If your Lennox Thermostat isn't responding when you press the touch screen, the keypad might be fully locked. Check installer setup number 0670 and change the keypad lock option if necessary.
P
Patricia CantuAug 27, 2025
How to fix Lennox ComfortSense L5732U Thermostat when "Heat On" is not displayed?
- J
  Jennifer GordonAug 27, 2025
  To fix this, set the System setting to Heat and ensure the temperature setting is above the current room temperature. If "Heat On" appears but the heating system still doesn't turn on, refer to the suggestions for 'Heating system does not turn on'.
P
Phillip NewmanAug 28, 2025
What to do when "Cool On" is not displayed on Lennox ComfortSense L5732U Thermostat screen?
- M
  Monica HarringtonAug 28, 2025
  To resolve this, set the System setting to Cool and make sure the temperature setting is below the room temperature. If "Cool On" is displayed but the cooling system doesn't activate, see the troubleshooting steps for 'Cooling system does not turn on'.
T
Theresa BurkeAug 29, 2025
What does "Wait" mean on my Lennox ComfortSense L5732U?
- B
  Brittany CastanedaAug 30, 2025
  The message "Wait" indicates that the compressor minimum-off timer is active. Allow up to five minutes for the compressor to turn on.
L
Lisa SantosAug 31, 2025
How to fix blank display on Lennox Thermostat?
- Y
  youngtriciaAug 31, 2025
  Ensure that fresh AAA alkaline batteries are correctly installed in the thermostat, following the markings inside.
P
Paul CarterSep 2, 2025
What to do if Lennox ComfortSense L5732U is calling for heat or cool but HVAC system is not operating?
- T
  Todd KnightSep 2, 2025
  If your Lennox Thermostat is calling for heat or cool, but the HVAC system isn't operating, it could be due to a few reasons. First, ensure the heating or cooling equipment is actually running. Then, verify the wiring and check installer setup number 0170 to ensure the proper system type is selected. Finally, verify the equipment operation in system test mode.
T
Thomas HunterSep 4, 2025
Why Lennox ComfortSense L5732U display does not come on?
- T
  Tara MartinezSep 4, 2025
  If your Lennox Thermostat display doesn't come on, it could be due to a lack of power. Check that there is 24V between the R and C terminals, and also ensure that the batteries are properly installed.
S
Susan MilesSep 5, 2025
Why Lennox ComfortSense L5732U heating or cooling does not come on?
- J
  John OliverSep 6, 2025
  If the heating or cooling system doesn't come on with your Lennox Thermostat, it could be due to a few reasons. The thermostat minimum-off time might be activated; wait up to 5 minutes for the system to respond. Also, ensure the system selection is set to heat or cool, and check installer setup number 0170 to make sure the proper system type is selected.

Lennox ComfortSense L5732U Specifications

General

Model Number	L5732U
Category	Thermostat
Display Type	Touchscreen
Wi-Fi Connectivity	Yes
Programmable	Yes
Indoor Temperature Range	40°F to 99°F
Humidity Control	Yes
Remote Sensor Capability	Yes
Type	Smart
Compatibility	Compatible with most HVAC systems
Power Source	Battery
Stages	2 Heat / 2 Cool