LAARS EBP 175 MBTU/h - Installation, Operation and Maintenance Instructions User Manual
Page 25
Endurance
Page 25
6.6 Other Control Functions
6.6.1 Using Buttons on Control
Figure 30 shows a drawing of the control,
including the placement of the four buttons.
Table 4
shows the actions associated with each of the buttons.
6.6.2 Alarm Acknowledge
When an alarm is activated (LO or one of the F
codes), the control will flash between the alarm display
and the supply temperature. Pressing the power button
(upper left button) for half a second will allow the user
to scroll through the menus for 30 seconds, before
reverting back to the alarm display.
6.6.3 Power On/Off
Pressing the power button on the control (upper
left button) for 3 seconds will turn the controller off.
This will not de-energize the boiler’s power, but will
de-energize the controller. The display will still work,
but the boiler will not acknowledge a call for heat, and
will not be able to fire. This allows the user to check
and set parameters when the boiler is unable to fire.
The display will show “OFF”. When the power button
is pressed again for 3 seconds, the display will show
“ON” briefly, and the boiler will then resume normal
operation.
6.6.4 Low Fire Hold
By pressing and holding the enter button and
the down arrow button for 2 seconds, the user will fix
the Endurance in low fire for 5 minutes. There is no
change in the boiler control display when the unit is in
this mode.
6.6.5 High Fire Hold
By pressing and holding the enter button and the
up arrow button for 2 seconds, the user will fix the
Endurance in high fire for 5 minutes. This can be used
to check and/or set combustion on the appliance. There
is no change in the boiler control display when the unit
is in this mode.
6.6.6 Pump Operation
The Endurance’s internal pump will operate
when any of the following conditions occur:
•
Low temperature mode.
•
Tank charge mode.
•
Heating system (T-T) call for heat.
•
Domestic hot water (DHW) call for heat.
•
Error condition detected.
•
Supply temperature detected as less than
“boiler on point”.
6.6.7 Anti-Condense Valve Operation
The control on the Endurance opens and closes
during a call for heat, and the call for heat continues,
this differential will determine at what point below
the Burner Control Point the Endurance will energize
again. The differential is fixed at 13°F (7°C) to ensure
that the transfer tank will be properly charged.
6.5 Calculated Control Values
There are several control values that are not
directly set by the user, but are calculated by the boiler
control, once the user has set the parameters in
Section
6.4.
These do not show on the control display, but it
is helpful to know how they affect the control logic of
the Endurance units.
6.5.1 ACV Release
When the Endurance is in tank charge mode, and
there is a call for space heating, the boiler needs to
know at what temperature it can release the ACV (anti-
condensing valve) back to the space heating position,
allowing the hot water to go into the system. The ACV
release point is the “burner off” point minus 5°F (3°C).
For example, if the “burner off” point is 190°F (88°C),
the ACV release point is 185°F (85°C). This means
that when the supply temperature reads 185°F (85°C)
in the tank, it will release the ACV for heating mode.
6.5.2 Tank Charge Setting
When the temperature at the tank sensor goes
below the tank charge setting, the Endurance will be
in “tank charge” mode. The tank charge setting equals
the programmed “burner off” point minus a fixed
40°F (22°C) differential. For example, if the “burner
off” point is 190°F (88°C), the Endurance will go into
“tank charge” mode when the tank sensor reads below
150°F (66°C). The ACV will close, and will run to
bring the supply temperature up to 185°F (85°C), and
the ACV will be released back to the space heating
mode (as long as there is no call for domestic hot
water).
6.5.3 Burner On Point
The “Burner On” point is calculated by
subtracting the “Burner On Differential (Dif)” from
the “Burner Control Point.” The differential is fixed at
13°F (7°C). This value tells the Endurance when to re-
energize during a call for heat in which the Endurance
reached its “Burner Off Point.”
6.5.4 Modulation Point
During a call for heat, the Endurance will ignite
at low fire and will begin to modulate to match the
load as it approaches the “Burner Control Point.”
There is no fixed temperature when this will occur, and
this value is not displayed on the Endurance.