Page 9
IPG-9
G. OPERATION
When properly adjusted, the pilot should produce a sharp, short, blue flame. If adjustment is
necessary, refer to the Ignition section.
H. SHUTOFF VALVE LEAK TESTING
Both safety shutoff valves in the gas pilot manifold must be leak tested by qualified personnel as
recommended by NFPA 86.
I. MAINTENANCE
All components of the pilot assembly are engineered to provide maintenance free operation. It is
sometimes necessary, however, to clear the mixer jet of any debris as this causes mixer
capacity to diminish. The mixer jet is easily cleaned by removing the air piping downstream of
the air ball valve and running a wire into the mixing tee opening through the jet. The gas inlet of
the mixer can also be cleaned by the same method. Fully removing the adjustment screw also
provides access to clean the mixer.
The pilot nozzle may become plugged with debris or carbon buildup. To clean the nozzle,
remove the pilot assembly from the burner. Disconnect the nozzle from the pilot assembly and
remove the spark plug assembly.
Check carefully to ensure the ceramic insulator is not
broken.
Clean the small tangential holes that surround the main hole and blow the nozzle out
with air when complete. Reassemble the pilot assembly, test fire, and reinsert the pilot into the
burner.
Periodically remove and inspect the spark plug. If the ceramic insulator is cracked or broken,
replace it. Clean the unit of any carbon buildup.
When replacing the plug, avoid over-
tightening the nut holding the plug to avoid cracking the plug’s ceramic insulator.
Before
use, ensure the plug’s wire electrode is centered in the pilot nozzle (see Figure 1 for setting
spark plug).
Figure 3. Cleaning Pilot Nozzle and Piloting Holes
WARNING
Do not attempt to operate a combustion system
with leaks present.
Gas Pilot Body
Gas Pilot Shell
Clean Pilot Nozzle
Orifices With Thin
Wire & Air.
Pilot Air/Gas Mix Inlet
Main Pilot Orifice.
Clean As Necessary
If any dirt or buildup accumulates on Gas
Pilot Shell, clean with wire brush. Keep
holes around Gas Pilot Shell Clear.
(NOT TO SCALE)
