LAARS EDN Series - Installation, Operation and Maintenance Instructions - Manual (Page 24)

Page 24 LAARS Heating Systems Company
6.4 Setpoint Menu
The setpoint menu is accessed by pressing the
enter button, and holding it for 3 seconds. Move
through the setpoint parameters by pressing the up
and down arrows. When the desired parameter is
displayed, press the enter button. Use the up and down
arrows to change the value of that parameter, and press
enter to save the change. Parameters that can be set on
the Endurance boilers are shown in the next sections.
The boiler control will automatically return to the
view mode if the control buttons are not pressed for 30
seconds.
6.4.1 “SP” Supply Temperature
Shown as “SP” in the control, the supply
temperature is the Burner Off Point. When the
temperature of the water that is leaving the boiler heat
exchanger reaches this setting, the Endurance shuts
off. If there is still a call for heat, it will energize again
when it reaches the Burner On Point. Default value is
190°F (88°C). It is adjustable from 170-220°F (77-
104°C) on EBP units, and from 155-220°F (68-104°C)
on the EDP/EDN units. SP has a fixed 10°F (6°C)
differential to the Burner Control Point. SP minus the
10°F (6°C) differential gives you the Burner Control
Point, which is the temperature the Endurance will
attempt to maintain, using its modulation features. The
differential between SP and the Burner On Point is
adjustable, using the Burner On Differential.
6.4.2 “PO” Pump Operation
This parameter, shown as “PO” in the selection
screen, allows the user to choose between the
Endurance pump running continuously (“Con”), or
running in the automatic mode (“Aut”) such that the
pump is energized only when there is a call for heat,
and has the option of a pump time delay when the call
for heat ends.
6.4.3 “Pd” Pump Delay
Pump delay is shows as “Pd” on the screen.
When pump operation “PO” parameter is set for
automatic (“Aut”), the user can choose the pump delay
time. This is the length of time that the Endurance
pump will run after the call for heat has ended. It can
be used to purge heat from the boiler, putting it into the
system or transfer tank. It is adjustable from 0 to 10
minutes, and the default value is 3 minutes.
NOTE: Some systems are designed such that the
Endurance pump will be left with only the internal
recirculation path when a call for heat has ended.
Make sure the system design is known before setting
a pump time delay, so that the water has a path
during the purge time.
6.4.4 “Oar” Outdoor Reset
Outdoor reset can be turned on and off using the
“Oar” parameter. You must have an outdoor sensor,
properly located, to use this function.
IMPORTANT NOTE: The Endurance outdoor reset
is limited, to ensure that internal water temperature
is high enough to prevent heat exchanger
condensation. EBP units are limited further, to keep
the temperature of the water in the 20 gallon transfer
tank high enough to serve the domestic water plate
heat exchanger at all times. This feature is not meant
to replace or mimic a system outdoor reset controller.
Figure 33. EBP Flow Schematic.