Instruction manual
Fi d b b il & h B il M l
Fi
nne
d
 co
pp
er tu
b
e gas 
b
o
il
ers 
&
 water 
h
eaters – 
B
o
il
er 
M
anua
l
27
F
F
13. Turn the knob on the pilot valve to on, Figure 18. 
14. Turn on all electric power to the boiler and set the operating 
control or thermostat to the desired se ing. 
15. With the unit operating at high purge the di erential air pressure 
should match those listed in Table 15. To adjust the di erential 
air pressure see the “AIRFLOW ADJUSTMENT” instructions 
in the “CHECKING AND ADJUSTMENTS” section.
Figure 19  Manual valve & manifold pressure tap
16.   e pilot should automatically light. Do not try to light the 
pilot by hand! 
17.  e pilot pressures should match those listed in Table 20. To 
adjust the pilot gas pressure see the “PILOT ADJUSTMENT” 
instructions in the “CHECKING AND ADJUSTMENTS” 
section. 
18. Distinguish pilot.
19. Turn the knob on the main gas valve to on, 225 through 400 
models, Figure 18. On 600 through 2300 models open the 
manual shuto valve located in the control compartment, Figure 
19.
20. Recycle boiler. 
21.   e manifold pressures should match those listed in Table 20. 
To adjust the manifold gas pressure see the “GAS PRESSURE 
ADJUSTMENT” instructions in the “CHECKING AND 
ADJUSTMENTS” section.
22. Replace the upper front jacket panel.
23. Check all safety switches for proper operation before placing 
boiler on-line.
Required Gas Pressure
Provide gas supply pressure at inlet to boiler gas train as follows:
 LP  Nat
  Minimum (in WC)  11  6
  Maximum (in WC)  14  14
Measure pressure when the boiler is  ring at full rate. Low gas 
pressure could indicate undersized gas line or insu cient gas supply.
Static and operating gas pressure required at the gas valve inlet is 
between 6 in WC and 14 in WC for natural gas and 11 in WC and 
14 in WC for propane. If the gas pressure is above this limit, a lock-up 
style regulator suitable for dead end service such as an Equimeter or 
Fisher must be installed to prevent increase (creep) of gas pressure 
when the units are not operating.   is pressure regulator (supplied 
by others) may be installed at the service entrance to each unit or 
a “master” regulator sized to handle multiple units may be utilized. 
Consult local gas utility or regulator manufacturer for recommenda-
tions to meet speci c job site requirements.
Table 20  Pilot & manifold pressures
On/Off
inches WC
mm WC
Pilot - NG
2.5 ± 0.3
63.5 ± 7.6
Pilot - LP
7.0 ± 2.0
177.0 ± 50.0
Low Fire
inches WC 
mm WC
Manifold - NG
1.4 ± 0.2
35.5 ± 5.0
Manifold - LP
4.0 ± 0.5
101.6 ± 12.7
High Fire
inches WC
mm WC
Manifold - NG
2.5 ± 0.2 
63.5 ± 5.0
Manifold - LP
9.3 ± 0.3
236.2 ± 7.6
Table 21  Combustion readings
Natural Fuel  Propane Fuel
CO
2
 %
7.0 - 7.5 (low) 8.2 - 8.8 (low)
7.8 - 8.5 (high) 9.2 - 9.9 (high)
O
2
 %
8.3 - 7.6 (low) 8.3 - 7.6 (low)
7.0 - 5.8 (high) 7.0 - 5.8 (high)










