Lennox International Inc. 81M28 Thermostat User Manual


 
How does Energy Efficient Recovery™ (EER™) work?
Energy Efficient Recovery™ is an energy saving feature. During a set back period (or set up in cooling), it allows the thermostat to
look up to two hours ahead to determine when to turn on the heating (cooling) system. During this time period, the second stage is
locked out until 20 minutes before the next programmed event to allow the first (and most efficient stage) to bring your home to the
desired temperature.
How does my remote outdoor sensor work?
The remote outdoor sensor (Part #46M98) can be used to aid in the comfort of your home or simply as a sensing device to inquire
about outdoor conditions. In most applications, the thermostat will have a display of the temperature sensed by the remote outdoor
sensor. With your heat pump system, the remote outdoor sensor can help determine when to turn on the second stage of heating for
optimal comfort.
Where should I install a remote outdoor sensor?
The remote outdoor sensor should be installed on the northern wall of your home, away from direct sunlight or other heat sources that
may affect its sensitivity.
NOTE: Use twisted pair wire (84X49) for the installation of the outdoor sensor.
What do the lights below the display mean?
The lights indicate different operations of the HVAC equipment.
With a call for heating or cooling, the HEAT or COOL light will be illuminated on the 81M26 and 81M27.
The AUX light indicates the second (backup) stage of heating. This is used only on the 81M28 model.
The CHECK light is used on all models. It indicates the equipment should be serviced by a qualified technician.
The EMER light indicates that the emergency heat is enabled in the HEAT/COOL menu (regardless of heat demand). This light is used
only on the 81M28 model.
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