33
Fig. 34: Differential Graph
Operating Modes
Mode 1 – Primary piping is prohibited.
Mode 2 – Setpoint operation using primary/secondary
piping, used for either hydronics or pool systems. The
control operates the heater to satisfy a remote system
sensor. The heater is turned off based on boiler max
and boiler differential (factory default). See Fig. 35.
Mode 3 – Dedicated DHW operation using UniTemp
80 piping. A call for heat is determined by the DHW
sensor and the DHW boiler target. The heater outlet
water is also controlled to the boiler target tempera-
ture. See Fig. 36.
*
RAYPAK
MODULATING
TEMP CONTROL
BOILER INLET
SENSOR IN
HEADER
BOILER OUTLET
SENSOR IN
HEADER
HYDRONIC
SYSTEM
TEMP
SENSOR
POOL
SYSTEM
TEMP
SENSOR
*Maximum 4 times the pipe diameter or 12”, whichever is less.
Fig. 35: Mode 2 Primary/Secondary Piping
RAYPAK
MODULATING
TEMP CONTROL
Fig. 36: Mode 3 Dedicated DHW
Mode 4 – Primary piping with outdoor reset is prohib-
ited.
Mode 5 – Outdoor reset using primary/secondary pip-
ing. The heater is operated as in Mode 2. However, the
target temperature is based on outdoor reset. See Fig.
37.
*Maximum 4 times the pipe diameter or 12”, whichever is less.
Fig. 37: Mode 5 Primary/Secondary Piping with
Outdoor Reset
