LAARS Pennant PNCV (Sizes 500-2000) - Install and Operating Manual - Manual (Page 37)

Pennant (500-2000) Page 37
piping, as described in Step 4.
12. Close make-up water valve and check strainer in
pressure reducing valve for sediment or debris
from the make-up water line. Reopen make-up
water valve.
13. Check gauge for correct water pressure and also
check water level in the system. If the height
indicated above the boiler insures that water is at
the highest point in the circulating loop, then the
system is ready for operation.
14. Refer to local codes and the make-up water
valve manufacturer’s instructions as to whether
the make-up water valve should be left open or
closed.
15. After placing the unit in operation, the ignition
system safety shutoff device must be tested. First,
shut off the manual gas valve, and call the unit
for heat. After the pre-purge and ignitor heat-up
time, the main gas terminals will be energized,
attempting to light, for four (4) seconds, and then
will de-energize. The unit will go into lockout
mode. Second, turn the power off and then on
again, open the manual gas valve and allow the
unit to light. While the unit is operating, close the
manual gas valve and ensure that power to the
main gas valve has been cut.
16. Within three (3) days of start-up, recheck all air
bleeders and the expansion tank as described in
Steps 4 and 8 above.
Important: The installer is responsible for identifying
to the owner/operator the location of all emergency
shutoff devices.
WARNING
Do not use this appliance if any part has been
under water. Immediately call a qualified service
technician to inspect the appliance
and to replace any part of the control system and
any gas control that may have been
under water.
6.3 Programming the Temperature
Control
The same temperature control is used on all
versions of the Pennant (in two-and four-stage
configurations), providing maximum flexibility to meet
the needs of any system. Before start-up, you must
program the temperature control for the type of system
you have. You must determine the type of piping the
system has, the mode the temperature control will
operate in, and the various settings for that mode.
6.3.1 System Piping
“Primary Secondary Piping”
In the context of these instructions, “primary
secondary piping” means the boiler provides heat to a
plumbing loop that has, in turn, one or more plumbing
loops connected to it, which provide heat to radiant
tubing, radiators, DHW heat exchangers, etc. This
plumbing loop is the “primary loop.”
In primary secondary piping modes, the
temperature control monitors the primary loop
temperature. The extra sensor that is shipped loose
with Pennant is installed in the primary loop. The
temperature control fires the boiler stages to provide
the “target temperature” at that sensor. Over time, the
temperature control will learn the system curve and
adjust the firing of the stages to meet the demand in
the most efficient way.
For complex systems, with variable speed
injection circulators, multiple temperature zones, etc.,
you may need to consult with a qualified engineer or
Laars Applications Engineering.
“Parallel Piping”
The term “parallel piping” means the Pennant is
supplying heat directly to one or more storage tanks,
radiators, radiant zones, etc., plumbed in series. In
these systems, the target temperature is the boiler’s
outlet temperature. An exception is for domestic hot
water systems using mode 3, where the extra sensor is
placed in the tank.
6.3.2 Choosing the Mode
There are six modes of operation for the Pennant
temperature control. The loose sensor must be installed
and connected prior to programming the temperature
control, as it provides sensing the “target” temperature.
The location of the sensor is dependent on the type
of piping used. Figures 4 through 8 show suggested
locations for the temperature sensor in various
hydronic piping configurations.
Modes 1 through 5 are the automatic modes,
requiring the diagnostic panel’s AUTO/MAN switch
(located on the slide-out control drawer) to remain in
the default AUTO position. These modes enable the
temperature control to fire the Pennant’s stages to meet
the demand of the system. In these modes, the Pennant
temperature control continuously samples the inlet,
outlet and target temperatures.
Mode 6 is the manual mode, and the AUTO/
MAN switch must be moved to the MAN position. An
external control, such as a building automation system
or multiple boiler control, just be wired to the field
wiring panel in order to fire the boiler, bypassing the
temperature control (see Section 5.3 for important
information about external staging controls and
building automation systems).
Table 11 contains information to identify the
mode you should use for your system.
6.3.3 Programming
Before programming, you must determine the
type of piping you have, the mode you will use, and