in
the combustion chamber to clear. IF YOU DETECT GAS ODOR
AT THE END OF THIS PERIOD DO NOT PROCEED WITH LIGHTING.
RECOGNIZE THAT GAS EVEN IF IT SEEMS WEAK, MAY INDICATE
PRESENCE OF ACCUMULATED GAS SOMEPLACE IN THE AREA
WITH RISK OF FIRE OR EXPLOSION. SEE THE FRONT PAGE FOR
STEPS TO BE TAKEN.
INLET GAS PRESSURE
The inlet gas pressure is measured at the main manual gas
shut-off valve, which is upstream of the unit’s gas valves and
pressure regulators. The maximum supply pressure of
13.8 inches W.C. (3.44 kPa) must not be exceeded. The
minimum values are shown in the GAS AND ELECTRICAL
CHARACTERISTICS table on pages 2 and 3 of this manual. The
gas valves supplied with the boiler are for low pressure service.
If the upstream pressure exceeds 13.8 inches W.C. (3.44 kPa) an
intermediate gas pressure regulator of the lockup type must be
installed.
CAUTION
SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL TO
SHUT OFF, SHUT OFF THE GAS SUPPLY AT A LOCATION
EXTERNAL TO THE BOILER (i.e. MAIN MANUAL GAS SHUTOFF
VALVE).
LIGHT THE BOILER IN ACCORDANCE WITH THE INSTRUCTIONS
PROVIDED ON THE LABEL AFFIXED TO THE BOILER’S FRONT
DOOR ON THE INSIDE. THESE INSTRUCTIONS ARE REPEATED
IN DETAIL ON THE FOLLOWING PAGE.
MANIFOLD PRESSURE CONNECTIONS
Take the manifold pressure, refer to figure 15, by removing the
pipe plug and inserting a suitable 1/8” NPT hose barb for
connection to the manometer/pressure gauge. Upon completion
of measurements and adjustments, remove the hose barb and
replace the pipe plug. Check for gas leaks and insure all
connections are gas tight.
FIGURE 18. HONEYWELL VALVE
GAS PRESSURE REGULATORS
For natural gas boilers, the gas pressure regulator is included in
the combination gas valve, figure 18. For propane boilers, the
gas pressure regulator is a separate device (except on the LW-
500 model), figure 15. The gas pressure regulator is factory set
to operate on the gas specified on the boiler rating plate.
DO NOT
subject the gas valve to inlet gas pressures of more than
13.8 in. w.c. (3.4 kPa). If higher gas pressures are encountered,
a service regulator is necessary.
A minimum supply gas pressure of 7.0" in. w.c. (2.74 kPa ) for
Natural Gas, or 11.0 in. w.c. (2.49 kPa) for Propane Gas, must be
maintained. The minimum supply gas pressure must be
maintained when all gas appliances connected to the system
are operating simultaneously and at full fire supply. Pressure
drops of more than 1/2” w.c. (0.12 kPa) are not acceptable.
The designed manifold pressures are 3.5 in. w.c. (0.87 kPa) for
natural gas and 10.0 in. w.c. (2.49 kPa) for propane gas. In order
to check and/or adjust the pressure regulator setting, perform
the following:
1. Set the system controller at its lowest setting so that the boiler
will not call for heat.
2. Refer to Figure 15 and MANIFOLD PRESSURE CONNECTIONS
for the proper method of measuring manifold pressure.
3. Reset the system controller dial to desired setting
(ensure ON/OFF switch is “ON”). The main burner will ignite.
4. With the main burner firing, adjust the pressure, if necessary, by
turning the pressure regulator adjusting screw with a
slot-type screwdriver. The pressure should be 3.5 in. w.c. (0.87
kPa) for natural gas or 10.0 in. w.c. (2.49 kPa) for propane gas.
• Clockwise to increase pressure.
• Counterclockwise to decrease pressure.
5. Set the system controller to lowest setting.
6. Remove pressure gauge and replace pipe plug in pipe nipple.
7. Set the system controller to desired setting.
DO NOT INCREASE THE PRESSURE ABOVE THAT SPECIFIED ON
THE RATING PLATE, AS OVER-FIRING WILL RESULT IN DAMAGE
TO THE BOILER.
If the gas pressure regulator cannot be adjusted to the correct
pressure, and there is sufficient gas supply pressure at the valve,
replace with a new gas valve (in the case of propane boilers,
replace with a new gas pressure regulator).
SAFETY CHECKS
After placing the boiler in operation, perform the following steps
to ensure proper performance:
FOR LB/LW-500 MODELS:
1. Manually shut off the gas supply by turning the top knob of the
gas control clockwise
to the “OFF” position. The boiler
will shut down (main burner extinguished) and will try and
re-light within 15 seconds. After three (3) ignition attempts
(or 1 attempt on CSD-1 models) the system will lock out. Check
that there is no voltage across the D-D or TH-TR terminals on
the gas control. Proceed to Step 2.
2. Shut off the gas supply to the boiler by closing the main manual
gas shutoff valve in the gas supply line located outside of the
boiler cabinet. Turn the top knob on the gas control
counterclockwise
to the “ON” position. Reset the power
to the boiler by turning the power switch on the boiler to the
“OFF” position, wait one (1) minute and then turn to the “ON”
position. If there is sufficient gas supply pressure to hold the
low gas pressure switch contacts closed, the unit will proceed
with the Trial-For-Ignition and as soon as the gas control opens,
the Gas Pressure Fail Light (red) on the DIA-SCAN II display
will come on and the gas control will close. If the gas supply
pressure is low where the low gas pressure switch contacts
remain open, the Gas Pressure Fail Light (red) on the
DIA-SCAN II display will remain on. The boiler will remain in
this state for approximately two minutes and then proceed to
enter lock out mode. Check that there is no voltage across the
gas control terminals before and after the unit enters the lock
out mode. The lock out message under this condition should
be either “Circulation Fail” or “Inducor Fail” depending upon
the state of the switch when the cycle is initiated.
Summary of Contents for LB 1000
Page 22: ...22 FIGURE 16 CONNECTION DIAGRAM ...
