420010970304 - LP-700 Rev. 000 Rel. 002 Date 4.21.21
58
C. Additional Precaution for Excess Flow Valve (EFV)
If an excess flow valve (EFV) is in the gas line, check the manufacturer’s
minimum and maximum flow capacity ratings. An improperly sized
EFV will not allow for a full flow of gas to the boiler and will cause the
boiler to malfunction. See Figure 73.
Figure 73 - Excess Flow Valve (EFV)
D. Checking Gas Pressure at the Boiler for Proper
Operation
NOTE: Refer to Figure 75 when checking gas pressure. Loosen the
bolts before checking the gas inlet pressure.
1. The boiler and its individual shutoff valve must be disconnected
from the gas supply piping system during any pressure testing of the
system at test pressures greater than ½ psi (3.5 kPa).
2. The boiler must be isolated from the gas supply piping system
by closing its individual manual shutoff valve during any pressure
testing of the gas supply piping system at test pressures equal to or
less than ½ psi (3.5 kPa).
The minimum and maximum inlet gas line pressures must meet the
requirements shown in Table 23.
Natural Gas
Minimum Pressure
3.5” WC
Maximum Pressure
10.5”WC
LP Gas
Minimum Pressure
8” WC
Maximum Pressure
13”WC
Table 23 - Gas Pressure Requirements
NOTICE
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.
Figure 74 - Gas Valve Detail
Figure 75 - Remove Yellow Cap
7. Use a manometer to test the gas pressure to make sure it meets
the minimum standards and does not exceed the maximum
standards of the boiler.
8. Leak test the gas line pipe before placing the boiler in operation.
Only use approved leak detector liquid solutions to check for
leaks.
9. Do not operate the boiler until all connections have been
completed and the heat exchanger is filled with water.
WARNING
!
When performing a pressure test on the gas line pipng, be sure the
boiler is disconnected or isolated if the test pressure is expected
to exceed 1/2 PSI (14” WC), as damage to the gas valve could
occur. Such damage could result in fire, property damage, serious
personal injury, or death.
4
2
1
Gas Inlet
1. Line pressure Test point
2. OFFSET Adjustment Screw
4. Throttle Adjustment Screw
Gas Outlet
WARNING
!
DO NOT REMOVE OR ATTEMPT TO MAKE AN ADJUSTMENT TO
SCREWS 2 and 4 WITHOUT A CALIBRATED COMBUSTION ANALYZER.
DOING SO COULD RESULT IN FIRE, PROPERTY DAMAGE, SERIOUS
PERSONAL INJURY, OR DEATH.
To check inlet gas pressure:
1. Remove yellow cap from line pressure test point. See Figure 74.
2. Unscrew “P in” screw.
3. Connect the manometer to the test point.
4. Check the inlet gas pressure.
5. Disconnect the manometer from the test point.
6. Tighten the “P in” screw (1 N/m).
7. Check for and repair any gas leaks.
8. Replace the yellow cap.
IN
