27
2. A sediment trap is included from the factory into
the supply piping at the boiler. Figure 5.1 shows the
sediment trap at the rear of the boiler near the base.
3. High and low gas pressure switches are provided on
the gas supply header inside the boiler cabinet. Figure
5.1 shows the pressure switch location.
4. Install the service valve, supplied by the factory, as
shown in Figure 5.1 on the inlet to the boiler gas
piping.
5. Install a ground joint union upstream of the service
valve to allow service to the appliance.
6. Maintain a minimum distance of 5 feet between the
supply gas pressure regulator and the appliance.
7. Check all gas piping for leaks prior to placing the
boiler in service. Use an approved gas detector, non-
corrosive leak detection fluid, or other leak detection
method to determine if there are leaks in the system.
If leaks are found, turn off the gas flow at the service
valve and repair as necessary.
8. Gas shutoff valves, located in the blower vestibule
cabinet area, are provided for each individual burner.
These valves are to be used in addition to the gas
service valve to interrupt gas flow to the individual
burners.
D. GAS SUPPLY PIPING - OPERATION
1. The gas line must be properly purged of air to allow
the boiler to operate properly. Failure to do so may
result in burner ignition problems.
2. Table 5.4 shows the maximum and minimum fuel gas
supply pressure to the boiler.
a. Gas pressures below 3.5 in. w.c. may result in
burner ignition failures and hard ignitions. A low
gas pressure switch has been provided with the
boiler to prevent low pressure conditions.
b. Gas pressures above 13.5 in. w.c. may result in
damage to the automatic gas valve. A high gas
pressure switch has been provided with the boiler
to prevent high pressure conditions.
c. The high and low gas pressure switch locations
can be seen in Figure 5.1.
3. To check the gas supply pressure to the gas valve:
a. Turn off the power at the service switch.
b. Close the gas shutoff valve.
c. Using a flat screwdriver, turn the screw inside the
inlet pressure tap fitting (see Figure 5.2) one turn
counterclockwise.
d. Attach the tube from the manometer to the inlet
pressure tap fitting.
e. Turn on the burner service switch.
f. Open the manual gas valve and start the boiler.
g. Read and record the gas pressure while the boiler
is firing.
h. Remove the call for heat and allow the burner to
shutdown normally with a full postpurge.
i. Turn off the burner service switch and close the
gas shutoff valve.
j. Remove the manometer tube from the inlet
pressure tap fitting.
k. Turn the internal screw clockwise to close the valve.
FUEL PIPING
When checking for leaks, do not use matches,
candles, open flames or other methods that provide
an ignition source. This may ignite a gas leak
resulting in a fire or explosion.
WARNING
Do not subject the gas valve to more than 13.5
in. w.c. (34 mbar) of gas pressure. Doing so may
damage the gas valve.
CAUTION
Model
Fuel Type
Fuel Inlet Pressure
(at Gas Valve for each Burner)
Minimum
Maximum
in. w.c.
kPa
in. w.c.
kPa
PFC-625/750
Natural Gas
3.5
0.9
13.5
3.4
LP Gas
8.0
2.0
Table 5.4: Maximum and Minimum Fuel Supply
Pressure
SERVICE VALVE
SEDIMENT TRAP
(ASSEMBLED)
HIGH GAS
PRESSURE
SWITCH
LOW GAS
PRESSURE
SWITCH
Figure 5.1:
G
as Supply Pipe and Shutoff
Liquefied Petroleum (LP) Gas or Propane is heavier
than air and, in the event of a leak, may collect in low
areas such as basements or floor drains. The gas
may then ignite resulting in a fire or explosion.
WARNING
