Advanced Heat Pump Features - Lennox X4147 Installation Instructions Manual

Advanced Heat Pump Features

The thermostat installer set−up may be
configured in several different ways to
ensure the desired system operation.
Heat Pump Application
Dual Fuel (Fossil Fuel) Aux. Heat
Outdoor Temperature Sensor and
Thermostat Control Aux. Heat
(No external dual fuel kit)
Installer set−up as follows:
S
Installer set−up number 0170 −−
option 7, 11, or 12 −− heat pump.
S
Installer set−up number 0200 −−
option 1 −− back−up heat is fossil
fuel.
S
Installer set−up number 0210 −−
option 0 −− no external fossil fuel
kit.
S
Installer set−up number 0340 −− not
shown −− outdoor temperature
sensor for control option chosen
by default.
S
Installer set−up number 0350 −−
choose appropriate balance point
temperature.
Heating Mode Operation
Outdoor Temp. above Balance
Point
When the outdoor temperature is
above the selected balance point, the
compressor satisfies the heating de-
mand. However, if the room thermostat
senses an indoor temperatature drop
of 2°F or more while the compressor is
operating, the heat pump operation will
stop and the furnace will satisfy the re-
maining heating demand.
NOTE − The balance point setting is
selected using Installer Set−Up Num-
ber 0350.
Heating Mode Operation
Outdoor Temp. below Balance Point
When the outdoor temperature is be-
low the selected balance point, only
the furnace (fossil fuel) operates to sat-
isfy the heating demand. The fan (G
terminal) does not energize when the
thermostat calls for heat.
Emergency Heat Operation
When the emergency heat mode of op-
eration is selected by the thermostat,
compressor operation is locked out.
The first stage of heat becomes what is
connected to the thermostat E termi-
nal. The second stage of heat be-
comes what is connected to the Aux.
terminal. In cases where there is only
one source of non−compressor heat,
the E terminal must be jumped to the
Aux. terminal.
Heat Pump Application
Dual Fuel (Fossil Fuel) Aux. Heat
Using External Dual Fuel Kit
Installer set−up as follows:
S
Installer set−up number 0170 −−
option 7, 11, or 12 −− heat pump.
S
Installer set−up number 0200 −−
option 1 −− back−up heat is fossil
fuel.
S
Installer set−up number 0210 −−
option 1 −− external fossil fuel kit is
controlling heat pump auxiliary
heat.
S
Installer set−up number 0340 −−
option 0 or 1 −− outdoor tempera-
ture sensor not used or used for
display only.
S
Installer set−up number 0350 −−
choose appropriate balance point
temperature.
Heat pump operation is determined by
external fossil fuel kit.
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