Harsco Industrial P-K THERMIFIC N700 Installation & Owners Manual page 39

the pilot flame doesn't hold the same size as the tube, looks very lazy, and/or very yellow, you may have
too much gas or some of the pilot air holes may be partially restricted with dirt. Correct as needed. If the
boiler uses sealed combustion and will use very cold combustion air you may need to use a higher gas
pressure for the colder weather to avoid nuisance pilot flame failures.
3.10.3.2 Setting the boiler combustion
Combustion adjustments on the P-K THERMIFIC
pressure adjustments in the following sequence:
1. Set the approximate cabinet air pressure (see Section 3.10.3.3).
2. Set the gas pressure by adjusting the gas pressure regulator (see Section 3.10.3.4).
3. Adjust the combustion for local conditions (see Section 3.10.3.5).
Adjust the oxygen (O
2
air. If the boiler has a ducted air supply, a range of air inlet temperatures will occur over the heating
season. A special setup table is shown in Section 3.10.3.6 below and must be followed.
3.10.3.3 Cabinet Air Pressure Adjustment
The air flow is pre-set at the factory prior to shipment. Only minor adjustments should be required.
To set the approximate cabinet air pressure, lock the flame safeguard in test position during the purge
cycle. Then adjust the air flow until the cabinet pressure is the same as shown on the "Factory Firetest"
label.
On/Off (700, 1000 Series only)
Loosen the setscrew on the air shutter and
open or close the shutter as required to adjust
the air flow. Re-tighten the holding screw after
adjustment.
On/Off (1500, 1700, 2000 Series)
The setscrews on the damper bracket assembly
hold the air damper in place. Loosen the nuts and
rotate the setscrews as required for proper air flow.
When the cabinet air pressure is correct, tighten
each setscrew and lock it in place with the nut.
Both setscrews must be touching the definite stop
before they are locked in place. Do not adjust any
other part of this mechanism.
) reading to approximately 7.5%, which corresponds to approximately 50% excess
®
boiler is a three step process that involves air and gas
Set Screw
Air Shutter
Increase/Open
39
®
P-K THERMIFIC Gas-Fired Boiler
Decrease/Close
Damper Bracket
Definite
Stop
Setscrew