THX9321 PRESTIGE
®
2.0 AND THX9421 PRESTIGE
®
IAQ WITH EIM
68-0311—02
148
Fig. 338. Wood stove with heat pump and backup electric strips. (For applications in which the thermostat only needs to
run the blower fan when stove is hot).
1 Select Geothermal Radiant Heat at ISU 2010. Connect Fan to U1, U2, or U3 as shown in the wiring diagram.
2 “U” terminals are normally open dry contacts when set up for geothermal radiant heat.
3 L/A terminal sends continuous output when thermostat is set to EM HEAT mode except when set up for Economizer or TOD.
See “Economizer Module Wiring Diagrams” beginning on page 151.
4 Y2 used with heat pumps that have 2 compressor stages.
NOTE: In Fig. 338, the thermostat will energize only the fan with a call for stage 1 heat. If the wood stove is hot, heat
comes from the fan coil. If the wood stove is cold, only the fan runs. The thermostat will upstage to the heat
pump and backup heat as needed to maintain the temperature.
O/B
AUX1
AUX2
O
W
Y
Y2
G
R
C
O
Y
Y2
R
C
L/A
TO THERMOSTAT
THERMOSTAT/EIM
HEAT PUMP
AIR HANDLER
HEAT PUMP
M31487
2
4
4
1
