EPV SERIES CONDENSING WATER BOILER
34-501 07/13
18
BURNER AND CONTROL MAINTENANCE
13.
Remove the flame safeguard control from its base. Check the connections in control mounting base; loose
connections can cause nuisance shutdowns.
NOTE
: Always secure gas lines and tag "Out of Service" before servicing burner nozzle or electrodes.
14.
Pull the nozzle assembly to check the flame and ignition electrodes. This is done by first disconnecting the gas
train by breaking at the unions. Then remove the nozzle assembly with the electrodes and pressure plate
attached. Disconnect the electrode wires. Take care not to damage the insulation on the electrodes.
15.
With electrodes exposed, check for the proper settings as in Figure 501-7 below. Check for any hairline cracks
in the insulators. Should replacement of burner electrodes be required, certain procedures must be followed. In
all cases, removal of electrodes is accomplished by loosening the electrode mounting clamps. Draw electrodes
out of the nozzle assembly through the holes in the pressure plate.
16.
Inspect electrodes for cracked ceramic or loose retaining studs that hold the wire within the ceramic. Select
the proper pressure plate hole to place each electrode and insert electrode through hole, retaining stud end
first.
17. Tighten electrode-mounting clamp slightly until electrode ceramics are seated firmly and completely in the
mounting bracket without gaps between ceramics and mounting bracket at the bearing faces.
18.
Measure and set electrodes according to Figure 23-7 below. After gaps and setting are complete, fully tighten
the electrode-mounting clamp. Do not overtighten or ceramic insulation may crack.
19.
Replace nozzle assembly; be sure to connect the flame and spark rod wires before installing nozzle assembly
fully into blast tube. Check connections on the ends of the flame and spark rod wires for good contact. Look for
properly stripped wire ends. Be sure connections are firmly attached to the flame and ignition rod ends.
Insulating boots can give a false feeling of proper seating.
DO NOT MOVE ELECTRODES.
Be careful not to
bump electrodes. Check fan wheel for free rotation.
20.
Reinstall gas nozzle assembly.
Pressure Plate Set Up and Tolerances
Figure 501-7