Aprilaire 8400 - Manual (Page 6)

6
OpERATION –
All mODElS
SElECT SySTEm mODE
(Off/HEAT/Em-HEAT/COOl/AUTO)
press to select:
AUTO: Thermostat automatically selects heating or
cooling depending on the indoor temperature.
Off: Heating and cooling systems are off.
HEAT: Thermostat controls only the heating system.
COOl: Thermostat controls only the cooling system.
Em-HEAT: Thermostat controls emergency/auxiliary
heat. Heat pump will not operate. (only for heat pumps
with auxiliary heat on models 8446, 8465, and 8466)
Applies to programmable versions (8463, 8465, 8466)
when in HOLD mode.
press or to adjust the current setting.
In AUTO use to switch between the HEAT and
COOL setting.
CHANgE TEmpERATURE SETTINg
61000651B 8400 Tstat Owners.indd 6 7/23/09 10:43:03 AM