65
Figure 33: Burner Flame
valves, throttle screw adjustments must be done
to both gas valves equally and simultaneously.
Refer to Figure 34 for location of throttle screw.
Verify CO is less than 100 ppm.
d. Lock boiler in low fire and allow boiler to
operate for approximately 5 minutes before
taking combustion readings. Press “Low” to
lock boiler in low fire.
WARNING
Asphyxiation Hazard. Offset screw is adjusted
at the factory to the specification. DO NOT
touch the offset screw if measured low fire O
2
(or
CO
2
) is within limits specified in Table 22 or 23.
e. If low fire O
2
is too low (CO
2
is too high),
increase O
2
(decrease CO
2
) by turning offset
screw counterclockwise in less than 1/8 turn
increments and checking the O
2
(or CO
2
) after
each adjustment. If boiler is equipped with 2 gas
valves, offset screw adjustments must be done
to both gas valves equally and simultaneously.
Refer to Figure 34 for location of offset screw.
Verify CO is less than 100 ppm.
f. If low fire O
2
is too high (CO
2
is too low),
decrease O
2
(increase CO
2
) by turning offset
screw clockwise in less than 1/8 turn increments
and checking the O
2
(or CO
2
) after each
adjustment. If boiler is equipped with 2 gas
valves, offset screw adjustments must be done
to both gas valves equally and simultaneously.
Refer to Figure 34 for location of offset screw.
Verify CO is less than 100 ppm.
IX. System Start-up
(continued)
2. Verify O
2
(or CO
2
) and CO are within limits
specified in Table 22 (natural gas) or Table 23 (LP
gas) at both high and low fire as described in the
following steps.
a. Lock boiler in high fire and allow boiler to
operate for approximately 5 minutes before
taking combustion readings. To lock boiler in
high fire, from the home screen, press “Adjust”,
“Adjust”, “Login”, “000”. Enter the password
“086” and press return arrow to close the keypad.
Press “Save”, “Adjust”, “High” to lock boiler in
high fire.
WARNING
Make sure that all adjustments at high fire are
made with the throttle, not offset screw (see
Figure 34). The offset screw has been factory set
using precision instruments and must never be
adjusted in the field unnecessarily.
Attempting to adjust the offset screw
unnecessarily could result in damage to the gas
valve and may cause property damage, personal
injury or loss of life.
b. If high fire O
2
is too low (CO
2
is too high),
increase O
2
(decrease CO
2
) by turning the throttle
screw clockwise in 1/4 turn increments and
checking the O
2
(or CO
2
) after each adjustment.
Refer to Figure 34 for location of throttle screw.
Verify CO is less than 100 ppm.
c. If high fire O
2
is too high (CO
2
is too low),
decrease O
2
(increase CO
2
) by turning the
throttle screw counter-clockwise in 1/4 turn
increments and checking the O
2
(or CO
2
) after
each adjustment. If boiler is equipped with 2 gas
Figure 34: Gas Valve Detail
Table 23: Typical Combustion Settings, LP Gas
Boiler
Model
High Fire
Low Fire
CO,
PPM
% CO
2
% O
2
% CO
2
% O
2
PHNTM399 11.4 - 9.5 3.5 - 6.5 11.4 - 9.1 3.5 - 7.0
Less than
100 PPM
PHNTM500 10.8 - 9.1 4.5 - 7.0 10.8 - 9.1 4.5 - 7.0
Summary of Contents for PHNTM399
Page 53: ...53 VIII Electrical continued Figure 26 Ladder Diagram...
Page 54: ...54 VIII Electrical continued...
Page 55: ...55 Figure 27 Wiring Connections Diagram VIII Electrical continued...
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Page 114: ...114 XIII Repair Parts continued PHNTM399 and PHNTM500...
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