Lennox International Inc. 4HP18LT - Manual (Page 25)

506470-01 Issue 1007
Fan Switch
In AUTO or INT (intermittent) mode, the blower operates
only when the thermostat calls for heating or cooling. This
mode is generally preferred when humidity control is a priority.
The ON or CONT mode provides continuous indoor blower
operation, regardless of whether the compressor or auxiliary
heat are operating. This mode is required when constant
air circulation or filtering is desired.
System Switch
Set the system switch for heating, cooling, or auto operation.
The auto mode allows the heat pump to automatically switch
from heating mode to cooling mode to maintain
predetermined comfort settings. Many heat pump
thermostats are also equipped with an emergency heat mode
which locks out heat pump operation and provides temporary
heat supplied by the auxiliary heat.
Indicating Light
Most heat pump thermostats have an amber light which
indicates when the heat pump is operating in the emergency
heat mode.
Temperature Indicator
The temperture indicator displays the actual room
temperature.
Programmable Thermostats
Your system may be controlled by a programmable
thermostat. These thermostats provide the added feature
of programmable time-of-day set points for both heating and
cooling. Refer to the user’s information manual provided
with your particular thermostat for operation details.
Preservice Check
If your system fails to operate, check the following before
calling for service:
Check to see that all electrical disconnect switches ar ON.
Make sure the thermostat temperature selector is properly
set.
Make sure the thermostat system switch is properly set.
Replace any blown fuses, or reset circuit breakers.
Make sure unit access panels are in place.
Make sure air filter is clean.
Locate unit model number and have it handy before calling.
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