Operating Instructions - RBI LCD Series Installation & Operation Manual

With the boiler off, run the system pump for at least 30
minutes and bleed the system piping using the bleed
valves. If strainers are used in the system piping, the
make-up water valve should be closed and the strainers
checked and cleaned.
The system expansion tank should be checked to
ensure that the correct water level in the tank is
maintained. The tank should be less than half full of
water with the system full and adjusted to the correct
operating pressure.
Start the boiler as described in the "OPERATING
INSTRUCTIONS". Run the boiler for at least an hour.
The system pump(s) and all radiation units must be
operated during this time. Ensure that the make-up
water valve is open.
Shut the boiler off and open the bleed valves to purge
the air trapped in the heating system piping. Close the
make-up water valve and check and clean the strainers
and make-up water pressure reducing valve.
Open the make-up water valve and adjust the system
pressure if necessary. The system should be checked
and bled after three days of operation.
BOILER/WATER HEATER
OPERATION
Staging Operation
The LCD boiler/water heater series is separated into on/
off and 2-stage units depending on the model selected.
The 225-400 models have on/off staging, while the 600
through 2300 models have a two stage option. Input
staging is controlled from an aquastat controller that
signals the relays to select the blower and gas valve
modes. Table 13 identifi es the stages and fi ring modes
associated with the standard single stage units. Table
14 identifi es the stages and fi ring modes associated with
the two stage option.
Table 13 - Firing Modes (L225-L2300)
Stage Firing Mode
Off Off
1 On
Table 14 - Firing Modes (L600-L2300)
Stage Firing Mode
Off Off
1 Low Fire
2 High Fire
LCD INSTALLATION AND OPERATION INSTRUCTIONS
The outlet water temperature is automatically controlled
by the aquastat. The optional staging function is
controlled by a return water aquastat. The return water
aquastat utilizes inputs from the inlet water temperature
sensors or optional tank sensors to stage the boiler/
water heater as required.
Pressure Switch Settings
Differential pressure switches are provided in the LCD
to shut down gas fl ow under a blocked fl ue or inlet
condition. A single pressure switch is used on the
standard models. One low fire and one high fire
pressure switch is used when the two-stage option is
employed. The low fi re pressure switch serves to shut
down gas fl ow if there is a blocked fl ue or inlet condition
during low fi re operation. Similarly, the high fi re switches
will shut down gas fl ow if there is a blocked fl ue or inlet
condition during high fi re operation. The differential
pressure is taken between the air plenum and the
pressure inside one of the main burners.
Pressure taps are provided in the control compartment
for taking the differential pressure readings, Figure 17.
Table 15 lists the differential pressure settings for all of
the models.
Figure 17 - Pressure Switch Tap(s)
Table 15 - Differential Pressure Settings (All Units)
Model
225-300
400
600-2300
High Fire
Inches W.C. mm W.C.
1.0 - 1.1 25.4 - 27.9
0.7 - 0.8 17.8 - 20.3
1.0 - 1.1 25.4 - 27.9
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