Heater Minimum (BOIL MIN)
The BOIL MIN is the lowest water temperature that the
Controller is allowed to use as a heater target temper-
ature (e.g. 105ºF). During mild conditions, if the
Controller calculates a heater target temperature that
is below the BOIL MIN setting, the heater target tem-
perature is adjusted to at least the BOIL MIN setting.
During this condition, if the heater is operating, the
MIN segment turns on in the LCD while the heater tar-
get temperature or heater operating sensor
temperature is viewed.
Additional plumbing and/or controls may be required to
maintain the heater at or above its minimum inlet tem-
perature.
Heater Maximum (BOIL MAX)
The BOIL MAX is the highest water temperature that
the Controller is allowed to use as a heater target tem-
perature. If the Controller does target BOIL MAX, and
the heater outlet sensor is near the BOIL MAX temper-
ature, the MAX segment turns on in the LCD while the
heater target, heater inlet, heater outlet or heater sup-
ply temperature is viewed.
Heater Target Temperature (BOIL
TARGET)
The heater target temperature is determined from the
mode of operation and type of demand applied. The
Controller displays the temperature that it is currently
trying to maintain at the operating sensor as BOIL
TARGET in the view menu.
The operating sensor for modes 2, 3, 5 and 7 is the
system sensor. If the Controller is not presently
enabled for heat, it displays “- - -“ in the LCD. In Mode
8, no heater target temperature is generated.
Pump Contact Operation
The pump contact operates when:
• While the burner is firing and primary / secondary
piping (Mode 2, 5, 7) is used. Once the burner is
shut off the boiler pump is shut off. Primary / sec-
ondary piping reduces standby losses by isolating
the boiler from the system while the burner is off.
9
Integral
compares the operating sensor temperature
offset (error) to the heater target temperature over a
period of time.
Derivative
determines how fast or slow the operating
sensor temperature is changing. If the temperature is
increasing slowly, the Controller modulates the heater
more rapidly. If the temperature is increasing quickly,
the Controller modulates the heater slowly, if at all.
Heater Mass (BOIL MASS)
The heater mass setting (1, 2 or 3) allows the installer
to adjust the Controller to the thermal mass of different
types of heat sources used. The heater mass setting
automatically determines the minimum on time and
minimum off time of the heater, and the PID modula-
tion parameters. A higher thermal mass setting
provides slower modulation, while a lower thermal
mass provides faster modulation.
Heater Mass Definitions
Mass 1
Low Volume, High Recovery
Mass 2
Medium Volume, Medium Recovery
Mass 3
High Volume Low Recovery
NOTE:
Always use a heater mass setting of 1 for
Raypak equipment. If the Controller continues to
respond too rapidly, contact Raypak.
Table A: Heater Mass Definitions
Fig. 17: Warm Weather Shutdown
NOTE:
If the installed heater is designed to operate
at a target temperature less than 80°F, set the BOIL
MIN adjustments to OFF and ensure that a cold
water protection package is employed.
