54
START-UP PROCEDURE
4. Use the ignition sequence, Figure 8.4, to follow the
light off and shutdown sequences and to assist in
troubleshooting operation problems. If the boiler
does not function properly, consult Section 10,
Troubleshooting.
5. After starting the boiler, be certain that all controls
are working properly, and that the combustion is
properly set up. Paragraphs 6 and 7, below, provide
instructions on how to do this.
6. Check that the boiler will shut down when the supply
water temperature reaches the control setpoint.
7. Combustion Test at High Fire (100% Modulation):
a. Enter the “Main Menu”
• “System Test”
• “Test State”
g
“High Power”
b. The burner will ignite and after a short stabilization
period, run at 100% of modulation.
c. Verify that the fan speed indicated is within 100
rpm of the High Fire fan speed listed in Table 12.3.
d. Using a suitable, calibrated combustion analyzer
determine the exhaust emissions of the boiler.
e. Use Table 5.5 & Table 5.6, Combustion Settings, to
determine the appropriate emissions levels.
f. If emissions are incorrect, adjust both throttle screws
the same amount to correct the combustion.
Note that increasing the throttle adjustment
(counterclockwise) will decrease O
2
and increase
the CO
2
. Decreasing the throttle (clockwise) will
have the opposite effect.
8. Combustion Test at Low Fire (1% Modulation):
a. Enter the “Main Menu”
• “System Test”
• “Test State”
g
“Low Power”
b. The burner will ignite and after a short stabilization
period, run at 1% of modulation.
c. Verify that the fan speed indicated is within 100
rpm of the Low Fire fan speed listed in Table 12.3.
d. Using a suitable, calibrated combustion analyzer
determine the exhaust emissions of the boiler.
e. Use Table 5.5 & Table 5.6, Combustion Settings, to
determine the appropriate emissions levels.
f. If emissions are incorrect, adjust both offset screws
the same amount to correct the combustion. Note
that increasing the offset adjustment (clockwise) will
decrease O
2
and increase the CO
2
. Decreasing the
offset (counterclockwise) will have the opposite
effect.
9. Turn System Test mode to “Off” so that the boiler will
modulate correctly in accordance with the load.
10. After removing the analysis probe from the vent pipe,
securely screw the analysis port cap back onto the
vent.
11. Record the combustion readings in the “Start-up
Combustion Record” in Appendix A. It is very
important to record all the information requested on
the sheet for follow up and troubleshooting.
G. VALVE ZEROING PROCEDURE
In case of valve replacement or operational issues with the
boiler, the procedure below can be used to re-establish an
equal setting on both valves.
The desired CO
2
for Natural Gas is 8.80 % with an inlet
gas pressure of nominal 7.0 INWC for both models. The
desired CO
2
for LP gas is 10.0% with an inlet pressure of
11” w.c. for the PFC-625 and 9.8% for the PFC-750. The
procedure for setting and adjusting the duel gas valves is as
follows:
1. With the boiler powered off and no call for heat
possible. Turn the throttle screw all the way in on one of
the gas valves by rotating it clockwise until you just meet
resistance. (Refer to Figure 5.2 for throttle screw location).
2. Note the radial location and turn the throttle screw out
counterclockwise 7 full turns for Natural gas and 4.5 turns
for LP gas. You should not meet resistance. If you do,
ensure you are rotating in the correct direction.
3. Complete Steps 1 and 2 on the second gas valve. The
order in which you initially set each gas valve will not
affect the adjustments.
4. Ensure proper water flow and power boiler on placing it
in high fire mode (See Table 8.K.0). If the boiler does not
ignite, increase the throttle screws in 1/2” turn increments
until ignition is achieved. Give the boiler time to reach its
max fan speed and reach a steady state approximately
1 to 2 minutes. Once steadied the CO
2
should read close
to 8.80% if it does not proceed to step 5 otherwise skip
to step 6.
5. Any adjustment made to one valve should be made
exactly the same on the other gas valve. Start with
making small 1/8 turn adjustments on both until you
reach your desired CO
2
percentage. If the CO
2
at high
fire is above 8.8% turn both throttle screws clockwise. If it
is below 8.8% turn both throttle screws counter clockwise.
After each adjustment allow at least 45 seconds for the
CO
2
reading to adjust. Repeat this step until you reach
the desired CO
2
%.
6. With high fire CO
2
at 8.8% turn the boiler to low fire
mode. If low fire is near 8.8% skip to step 8 otherwise
proceed to step 7.
7. Low fire adjustments are made using the offset screw on
each valve. Any adjustment made to one valve should
be made exactly the same on the other valve. Start with
making small 1/8 turn adjustments on both until you
reach your desired CO
2
percentage. If the CO
2
at low fire
is reading higher than 8.8 % turn both offset screws
counter clockwise. If it is below 8.8 % turn both
offset screws clockwise. (refer to Figure 5.2 for screw
location) Repeat this step until you reach the desired
CO
2
%. Note: Adjustments on low fire offset screws are
opposite direction to the high fire throttle screw
adjustments and should only be made in low fire mode.
8. Set the boiler back to high fire mode and monitor CO
2
.
Significant adjustments to the valve offset can cause high
fire settings to drift. If the CO
2
% is no longer close to
8.8% repeat steps 5-8 until the readings are accurate are
at the desired setting for both high and low fire.
