Lennox S40 User Manual page 20

Function or
Icon
Screen Text
Defrosting
Emergency
Heat
Auxiliary Heat
Will start soon
Ambient
lockout
Fan is running
Fan in auto
mode is active
Fan in circulate
mode is active
Table 2. Home and Status Screens Icon Descriptions
The heat pump system is defrosting the outdoor unit coil. Not available for non-heat pump systems.
All heat pumps operating in northern climates below 35°F (1.6°C) normally need a supplemental heating source. Usually
it is in the form of electric heating provided by the indoor unit. Other sources could be gas, oil, or hot-water back-up
systems as well. The supplemental heat is also referred to as "second-stage" or "back-up" heating, with "first-stage" being
the heat pump only. Emergency heat is supplemental heat (2nd stage) is used solely, without the use of a heat pump (1st
stage heat). Not available for non-heat pump systems.
If outdoor temperature is above the high balance point, only the heat pump will operate - default 50°F (10°C) high. If
outdoor temperature is below the low balance point, only auxiliary heating will operate - default 25°F (-4.0°C) low. If
outdoor temperature is in-between the high and low balance point, both the heat pump and auxiliary heat sources can
operate. Not available for non-heat pump systems.
A five minute safety delay prevents the compressor from operating too soon after shut-down to allow internal pressures to
equalize.
This indicates that either the outdoor temperature is above or below the balance point temperature settings. The low
balance point setting prevents heat pump heating below the set point and back up heat will be used. Typically the default
is 25°F (-4.0°C), but that setting can be adjusted by the dealer. At 25°F (-4.0°C) or below for example, only auxiliary
heating (electric or gas) is used. If the high balance point is set to 50°F (10°C) for example, which is also adjustable by
the dealer, then auxiliary heat will not be allowed. Only heat pump heating will be used. Anytime the outdoor temperature
is below or above the balance point temperature settings, the ambient lockout notice will appear on the Home screen.
Fan set to ON. Fan is NOT following the schedule and runs continuously until it is changed from the selected mode.
Fan set to Auto. Fan will follow the fan setting in the selected schedule.
Fan set to Circulate. Fan is following schedule and cycles during periods of equipment inactivity. Circulate run time is
dependent on user settings.
Purpose
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