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Lennox 51M34 L3511C ComfortSense 3000, Programmable Thermostat, 5-2 Day, 1 Heat/1 Cool Gas/Electric

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Programmable & Non-Programmable Thermostats

Accurate temperature control

1 Heat/1 Cool - Gas/Electric

With simple one-touch operation and precision temperature control, ComfortSense® 3000 Series Programmable & Non-Programmable Thermostats are incredibly convenient. Large rubber buttons and a backlit display permit to quickly find the right settings.

Energy Efficiency

  • Dual-fuel capability (multi-stage heat pump version only)—increases the efficiency of dual-fuel heating systems by automatically alternating between gas and electric operation

Home Comfort

  • 5-day/2-day programming—homeowners can customize a temperature schedule for weekdays and weekends, with up to two time periods per day
  • Non-programmable model available for ease of use in basic applications
  • Easy integration—works with advanced heating and cooling systems to properly regulate temperature inside the home
  • Automatic changeover between heating and cooling operation, depending upon the demand (7-day programmable only)

Reliable Performance

  • Large buttons and backlit display—find the right setting, day or night
  • Digital control—accurately maintains the desired temperature


Brand Lennox
Catalog Number 51M34
Model/Part Number L3511C
Minimum Order Quantity 0.0
Base Unit of Measure Unit(S)
EAN / UPC 66255140289
Product Depth 1.375 IN
Product Height 3.5 IN
Product Width 4.5 IN
Type Conventional
Gross Weight 0.85 LB
Family ComfortSense 3000
Hertz 60 hz
Changeover Manual
Humidification Control No
Lennox Brand Comparison 51M34
Program Type 5-2 Day
Communicates with Lennox No
Stages Quantity 1 Heat/1 Cool
Intelligent Recovery No
WiFi Remote Access No

Free Shipping Next Business Day

Customer Reviews

Based on 1 review
Robert Ploss

Ordered with telephone call -- friendly and efficient. Order shipped the same day and arrived when promised. Installation was very easy; just removed the old thermostat and plugged in the new one. In ten seconds, I was up and running. It's nice to have a new unit to replace the old worn-out one. I will definitely be a repeat customer for any future needs!