LAARS Heating Systems
Page 102
If the water level exceeds ¼ of the volume of the
expansion tank, open the tank drain, and drain to
that level.
10. Shut down the entire system and vent all radiation
units and high points in the system piping, as
described in Step 4.
11. Close the make-up water valve. Check the strainer
in the pressure reducing valve for sediment or
debris from the make-up water line. Reopen the
make-up water valve.
12. Check the gauge for correct water pressure and
also check the water level in the system. If the
height indicated above the boiler ensures that water
is at the highest point in the circulating loop, then
the system is ready for operation.
13. 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.
14. Press the reset on the low pressure switch.
15. After placing the unit in operation, the ignition
system safety shutoff device must be tested.
First, shut off the manual gas valve, and then call
the unit for heat. The main gas terminals will be
energized and attempting to light for five seconds
and then will de-energize. The unit will go into
lockout after the required number of trials for ignition
periods.
Second, press the manual reset button on the boiler
control, or the user display, 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
previously in Steps 4 and 8.
NOTE - The installer is responsible for identifying
to the owner/operator the location of all emergency
shutoff devices.
WARNING
Do not use this unit if any part has been under water.
Immediately call a qualified service technician to
inspect the unit and to replace any part of the control
system and any gas control that may have been
under water.
SECTION 10 Initial startup
Instructions
10.A Filling the Boiler System
1. Ensure the system is fully connected. Close all
bleeding devices and open the make-up water
valve. Allow the system to fill slowly.
2. If a make-up water pump is employed, adjust the
pressure switch on pumping system to provide a
minimum of 12 psi (81.8 kPa) at the highest point in
the heating loop.
3. If a water pressure regulator is provided on the
make-up water line, adjust the pressure regulator
to provide at least 12 psi (81.8 kPa) at the highest
point in the heating loop.
4. Open any bleeding devices on all radiation units at
the high points in the piping throughout the system,
unless automatic air bleeders are provided at those
points.
5. To remove all air from the heat exchanger, cycle the
boiler pump on and off 10 times (10 seconds on and
10 seconds off). Then run the system and boiler
pumps for a minimum of 30 minutes with the gas
shut off.
NOTE - There are three (3) air bleeds located on top
of the water manifolds.
WARNING
Failure to remove all air from the heat exchanger
could lead to property damage, severe injury or death.
6. Open all strainers in the circulating system, check
the operation of the flow switch (if equipped), and
check for debris. If debris is present, clean out the
strainers to ensure proper circulation.
7. Check the liquid level in the expansion tank. With
the system full of water and under normal operating
pressure, the level of water in the expansion tank
should not exceed ¼ of the total with the balance
filled with air.
8. Start up the boiler following the procedure in this
manual. Operate the entire system, including the
pump, boiler, and radiation units for one hour.
9. Recheck the water level in the expansion tank.
