Gas Valve Replacement Instructions

3
• If there is a significant drop in pressure (more than 1"
in a 5 second span), tighten the gas inlet fittings.
• When no leaks are detected, remove the manometer
and tighten the screw inside the inlet gas pressure port
as shown in Figure 7.
• Open boiler gas shut off cock.
STEP 7 – COMBUSTION SETUP
• Turn on the service switch to power the boiler.
• Verify the display reads “Standby”.
• Press the “MENU” and “SELECT” buttons
simultaneously to enter the Installer Menu.
• Using the  key, choose the last menu option,
“System Test”.
• Press the  key 3 times and press select to choose
“High Power”.
• Allow the boiler to start and ramp up to 100% input.
• Check combustion by inserting the analyzer probe into
the test port.
• If there is no test port available, drill and tap into the
PVC or CPVC pipe as shown in Section 9.0 of the
Installation, Operation and Maintenance Manual.
• Refer to Table 1 for recommended combustion values.
• Adjust the throttle screw to as shown to Figure 8 and
Table 2 to dial in the acceptable range.
• Change input rate to low power. Modulation will drop
to 1%.
• Repeat combustion readings and compare with chart.
If the low fire readings do not agree with Table 1 turn
off the boiler and call your PB Heat Representative.
Do not make throttle adjustments at low fire.
• Record combustion readings and installer information
in the space provided in the manual.
Figure 7: Gas Leakage Test Instructions
PUREFIRE GAS VALVE REPLACEMENT INSTRUCTIONS
Table 1
Combustion Settings
High Firing rates and Low Firing rates on all Models
Natural Gas Propane LP
Low High Low High
Carbon
Monoxide
(CO)
< 50 ppm < 100 ppm < 50 ppm < 100 ppm
Carbon
Dioxide
(CO
2
)
8.5% – 9.5% 8.5% – 9.5% 9.5% – 10.5% 9.5% – 10.5%
Table 2
*Very high CO with low CO
2
indicates possible unburned gas due to
insufficient air
Turning Gas Valve Throttle Screw
If CO is
not too high
If CO is
too high
If CO
2
is
too high
Turn Clockwise (–) Turn Clockwise (–)
If CO
2
is
too low
Turn Counterclockwise
(+)
Turn Clockwise (–)*
Figure 8