2.8.6 Wiring single-stage heat
pump with a boiler or combi
boiler as backup (emergency heat
on T-stat)
Required if the boiler or the combi boiler does not have control of the pump
Optional: 'G' for fan-only operation and 'C' for t-stat common
Dry contact from the air handler to the boiler or combi boiler that enables a call for heat
The reversing valve operation is selectable with the AHU app: the default setting energizes
the O/B terminal during cooling
Required: the outdoor sensor for balance point control of backup heat source is available
separately as IBC outdoor sensor kit P-9067.
Required: sensors for cooling applications are available separately as IBC A/C sensor kit P-
1015
W2 call from T-stat activates the outdoor unit emergency heat
Figure 41 Single-stage heat pump with a boiler or combi boiler as backup, emergency heat on T-stat wiring
2.8.6 Wiring single-stage heat pump with a boiler or combi boiler as backup (emergency heat on T-stat)