Required if boiler does not have an integral pump.
Dry contact from air handler to boiler / enables call for heat.
Reversing valve (O or B) is selectable via the blower control interface
W1 = heat pump, W2 = energize TT for boiler - removes heat pump
Not used
Figure 44
Single-stage heat pump with boiler backup, primary/secondary piping (2-stage thermostat)
42
Section: Installation
Summary of Contents for AHU Series
Page 1: ...INSTALLATION OPERATING MANUAL Air Handling appliances AHU 800 AHU1200 AHU 1600...
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Page 5: ...5 3 Fault Codes 67 Air handling appliance parts diagram 70 3...
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