LP-517 Rev. 000 Rel. 019 Date 7.21.20
36
Use two wrenches when tightening gas piping at the boiler: One to
prevent the boiler gas line from turning. Failure to prevent the boiler
gas connection from turning could result in damage to the gas line
components, substantial property damage, severe personal injury,
or death.
CSA or UL listed flexible gas connections can be used when installing
the boiler. Flexible gas connections have different capacities and
must be sized correctly for the connected boiler firing rates. Consult
with the flex line supplier to assure the line size is adequate for the job.
Follow local codes for proper installation and service requirements.
B. Gas Table
Refer to Table 12 to size the supply piping to minimize pressure drop
between the meter or regulator and unit. Maximum capacity of pipe
in cubic feet of gas per hour cannot have a pressure drop greater than
.5 w.c.
C. Check Inlet Gas Pressure
The gas valve is equipped with an inlet gas pressure tap that can be
used to measure the gas pressure to the unit. To check gas pressure,
perform the steps listed below:
1.
IMPORTANT!
Before you connect to the inlet pressure, shut off the
gas and electrical power to unit.
2. Loosen the pressure tap with a small screwdriver. Refer to Figure 28
for location.
3. Each unit is equipped with a needle valve that will accept a 5/16 ID
hose to connect to a digital manometer or liquid gauge to measure
incoming pressure from 0-35” w.c.
4. Turn on the gas and power up the unit.
5. Put the unit into manual test mode. In test mode, monitor pressure
to assure it does not drop below 1 inch from its idle reading. If gas
pressure is out of range or pressure drop is excessive, contact the gas
utility, gas supplier, qualified installer, or service agency to determine
correct action that is needed to provide proper gas pressure to the unit.
If Gas Pressure is within normal range proceed to Step 6.
6. Exit test mode, then turn power off and shut off gas supply at
the manual gas valve before disconnecting the hose from the gas
monitoring device. Tighten screw on the pressure tap and turn gas on.
Check for leaks with soapy solution. Bubbles will appear on the pipe to
indicate a leak is present.
Ensure the pressure tap screw is properly tightened to prevent gas
leaks. Failure to do so could cause substantial property damage,
severe personal injury, or death.
The gas piping must be sized for the proper flow and length of
pipe to avoid pressure drop. The gas meter and regulator must be
properly sized for the total gas load. If you experience a pressure drop
greater than 1” w.c. (.87 kPa), the meter, regulator or gas line may be
undersized or in need of service. You can attach a manometer to
the incoming gas drip leg after removing the cap. The gas pressure
must remain between 3.5” (.87 kPa) and 14” (3.5 kPa) during stand-
by (static) mode and while in operating (dynamic) mode.
If an in-line regulator is used, it must be a minimum of 10 feet from
the boiler. It is very important that the gas line is properly purged
by the gas supplier or utility. Failure to properly purge the lines,
or improper line sizing, will result in ignition failure. This problem
is especially noticeable in NEW installations and empty tank
situations. This situation can also occur when a utility company
shuts off service to an area to provide maintenance to their lines.
This gas valve must not be replaced with a conventional gas valve
under any circumstances.
DO NOT adjust or attempt to measure gas valve outlet pressure.
The gas valve is factory-set for the correct outlet pressure and
requires no field adjustment. Attempts by the installer to adjust or
measure the gas valve outlet pressure could result in damage to
the valve and cause substantial property damage, severe personal
injury, or death.
Natural Gas Supply Piping Capacity Chart
(0.6 Specific gravity gas; 0.5” WC pressure drop)
*Schedule 40 iron pipe size in nominal inches
Cubic Ft. Hr.
750
1500
2250
3000
3750
4500
5250
6000
Model
1 Boiler
2 Boilers
3 Boilers
4 Boilers
5 Boilers
6 Boilers
7 Boilers
8 Boilers
750 @ 100’ of
Pipe
2”
2 1/2”
3”
3”
3 1/2”
3 1/2”
4”
4”
750 @ 250’ of
Pipe
2 1/2”
3”
3 1/2”
4”
4”
5”
5”
5”
Cubic Ft. Hr.
1000
2000
3000
4000
5000
6000
7000
8000
Model
1 Boiler
2 Boilers
3 Boilers
4 Boilers
5 Boilers
6 Boilers
7 Boilers
8 Boilers
1000 @ 100’ of
Pipe
2”
3”
3”
3”
4”
4”
5”
5”
1000 @ 250’ of
Pipe
2 1/2”
4”
4”
4”
5”
5”
5”
6”
Table 12 - Gas Supply Piping Size Chart for Boilers
Strain on the gas valve and fittings may result in vibration,
premature component failure and gas leakage, and result in fire,
explosion, property damage, severe personal injury, or death.
Adjustments to the throttle screw or offset may only be made by
a qualified gas technician using a calibrated combustion analyzer
capable of measuring CO2 and CO. Failure to follow this instruction
could result in fire, explosion, property damage, severe personal
injury, or death.
Natural or LP Gas
Minimum Pressure
3.5” WC
Maximum Pressure
14”WC
Table 13 - Gas Pressure Requirements
Do not fire (operate) the boiler until all connections have been
completed and the heat exchanger is filled with water. Doing so
will damage the boiler and void the warranty.