Reznor RPBL Unit Installation Manual - Manual (Page 55)

Form I-SSCBL/RPBL, P/N 149159 R7, Page 55
10.2.2 Pilot and Main
Burners
Burner Rack Removal Instructions
Instructions apply to all furnace sections.
1. Turn off the gas supply.
2. Turn off the electric supply.
3. Remove control access side panel.
4. Disconnect the pilot tubing and flame sensor lead (spark pilot).
5. Mark and disconnect electric valve leads.
6. Uncouple the union in the gas supply.
7. Remove sheetmetal screws in the top corners of the burner rack assembly.
8. Pull "drawer-type" burner rack out of the furnace.
To disassemble the burner rack:
1. Remove Carryover System --
Natural Gas - Remove the flash carryover system from the "manifold end" of the
burner rack. NOTE: Natural gas burner racks manufactured prior to Series 6 have
a lighter tube carryover system. Break the lighter tube connection at the orifice and
remove the supply tubing, the drip shield and the lighter tube.
Propane - Break the lighter tube connection at the regulator and remove the lighter
tube orifice supply tubing; remove the retaining screws in the drip shield and the
shield; remove the retaining screws and slide out the lighter tube.
2. Pull main burners horizontally away from injection opening and lift out.
3. Remove manifold bracket screws and remove manifold.
4. Change main burner orifices, if necessary.
5. Remove screws and lift out pilot burner.
Follow the instructions to clean. To re-assemble and replace, reverse the above proce-
dures being careful not to create any unsafe conditions.
CAUTION: When
cleaning, wearing
eye protection
is strongly
recommended.
equilibrium, close the manual shutoff valve. Observe the gas pressure. There
should be no loss of gas pressure on the manometer. If the manometer indicates
a loss of pressure, replace the combination gas valve before placing the heater in
operation.
NOTE: Operational pressure settings and instructions for checking pressure settings
are in Paragraph 6.2.
In the event the pilot flame is short and/or yellow, check the pilot orifice for blockage
caused by lint or dust accumulation. Remove the pilot orifice and clean with air pres-
sure. DO NOT REAM THE ORIFICE. Check and clean the aeration slot in the pilot
burner.
Clean the metal sensing probe and the pilot hood with an emery cloth and wipe off
the ceramic insulator. Check the spark gap; spark gap should be maintained to .100".
(Refer to FIGURE 58.) After the pilot is cleaned, blow any dirt away with compressed
air.
Main burners may be cleaned using air pressure. Use an air nozzle to blow out scale
and dust accumulation from the burner ports. Alternately blow through the burner ports
and the venturi. Use a fine wire to dislodge any stubborn particles. Do not use anything
that might change the port size.
Clean the burner rack carryover systems with air pressure.
Cleaning Pilot and
Main Burners
Pilot and Spark Ignition
System
The ignition controller provides the high voltage spark to ignite the pilot service and also
acts as the flame safety device. After ignition of the pilot gas, the controller electroni-
cally senses the pilot flame. A separate solid metal probe in the pilot burner assembly
is used to sense the flame. A low voltage DC electrical signal is imposed on the metal
probe which is electrically insulated from ground. Proper operation of the electronic
spark ignition system requires a minimum flame signal of .2 microamps DC as
measured by a microampmeter. When the pilot flame impinges on the sensing probe,
the flame acts as a conduction path to ground. This completes the DC circuit; the igni-
tion controller responds by energizing the main gas valve.
CAUTION: Due to high voltage on pilot spark wire and pilot electrode, do
not touch when energized. See Hazard Levels, 2.