Raypak XFyre 300A Installation & Operating Instructions Manual page 15

gles off the System Pump (P2) when an indirect call for
heat is present. The Boiler Pump (P1) runs during any
call for heat. The Indirect DHW Pump (P3) runs during
an indirect call for heat with no "off" delay. The Boiler
Pump (P1) and System Pump (P2) delay "off" as user
defined in the ADJUST menu. The System Pump (P2)
runs whenever the system is enabled for heating and
the outdoor air temperature is lower than the WWSD
temperature setting (if utilized) unless an indirect call
for heat is present with priority.
Mode 3 (Type H Units Only)
This mode selection is for hydronic heating systems
with single or multiple boilers (Maximum 4 boilers) in
primary/secondary piping configuration with or without
Outdoor Air Reset (S4) with indirect DHW on the boil-
er loop (with priority). The system temperature is
controlled by the Supply sensor (S3) whenever the
indirect call for heat is not active. The DHW Supply
sensor (S5) determines the indirect call/tank setpoint.
During an indirect call for heat the boiler firing rate is
Fig. 7: MODE 1 - Applications with Primary/Secondary Piping
Fig. 8: MODE 2 - Single Boiler with Indirect
on System Loop
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Key:
S1: Boiler Outlet Sensor
S2: Boiler Inlet Sensor
S3: System Sensor
S4: Outdoor Air Sensor
S5: Indirect Tank Sensor
S6: Supply Sensor to Indirect
P1: Boiler Pump
P2: System Pump
P3: Indirect DHW Pump