6
Domestic Hot Water Operation,
Uni-Temp 80 Piping (Mode 3)
Mode 3 is designed for dedicated DHW operation
using Unitemp 80 piping. The Controller operates the
heater to maintain a tank temperature at the system
sensor.
Mode 3 requires the use of three water sensors. The
inlet water sensor is located in the inlet side of the
in/out header and the outlet sensor is located in the
outlet side of the in/out header. The system sensor
(terminals 6 and 4) must be located in the storage
tank, as shown in Fig. 10.
Outdoor Reset and Override Operation with
Primary Piping
Mode 4 (Mode = 4)
(Not Supported)
Mode 4 is designed for outdoor reset and override
operation using Primary Piping. Once a CFH is pres-
ent, the control stages the heater to maintain the
calculated outdoor reset target at the heater outlet
sensor. Once an indirect DWH override is present, the
control stages the heater to maintain the heater target
2 at the heater outlet sensor. If both demands are
present at the same time, the control operates at the
higher of the two targets.
Outdoor Reset and Override Operation with
Primary/Secondary Piping
Mode 5 (Mode = 5)
Mode 5 is designed for outdoor reset and override
operation using Primary /Secondary Piping. The CFH
is available to provide outdoor reset for hydronic heat-
ing systems. The override can be used to heat an
indirect domestic hot water tank.
Once a CFH is present, the control stages the heater
to maintain the calculated outdoor reset target at the
heater system sensor. Once an indirect DHW override
is present, the control stages the heater to maintain
the heater target 2 at the heater system sensor. If both
demands are present at the same time, the control
operates at the higher of the two targets.
Mode 5 requires the use of three water sensors and
one air sensor. The inlet water sensor is located in the
inlet side of the in/out header. The outlet sensor is
located in the outlet side of the in/out header. The sys-
tem sensor (terminals 6 and 4) must be located on the
system supply pipe, as shown in Fig. 11.
The outdoor air sensor must be located on the coldest
side of the building in a shaded area out of direct sun-
light.
Fig. 10: Uni-Temp 80 Piping (Mode 3)
RAYPAK TEMPERATURE
CONTOLLER
SYSTEM RETURN
SYSTEM
SUPPLY
ALTERNATE
SENSOR
LOCATION
4 OR MORE
STAGES
SYSTEM SENSOR
MAIN
SYSTEM
PUMP
(BY OTHERS)
OPTIONAL INTEGRAL PUMP
BOIL OUT SENSOR
BOIL IN SENSOR
PUMP LOCATION
ON MODELS WITHOUT
INTEGRAL PUMP
*
*
MAXIMUM 4 TIMES THE PIPE DIAMETER OR 12”, WHICHEVER IS LESS.
OUTDOOR
AIR
SENSOR
Fig. 11: Primary/Secondary Piping with Outdoor Reset
(Mode 5)
