Weil-McLain EG 6 Series Manual page 37

Universal Control Systems
Troubleshooting – (EG, PEG & EGH steam boilers)
NO SPARK – System does not work – without vent damper
CHART 8
Electrical shock hazard — Wherever you see ▲ TURN OFF POWER ▲ , follow the instructions.
–
Failure to follow instructions could result in severe personal injury, death or substantial property damage.
Correct by making connections.
Check for open thermostat or circulator relay (where
used) or check for loose wire connections, defective
spill switch or rollout thermal fuse element, or open
LWCO or limit contacts.
If LWCO, spill switch or rollout thermal fuse
element contacts are open, determine
cause and correct condition. Failure to do so will cause
severe personal injury, death, or substantial property
damage.
Replace ignition control.
Securely connect, then turn ON supply voltage and re-test.
Is spark gap 0.125" and located in pilot gas steam?
No
Replace pilot assembly, turn ON
supply voltage, operate system sev-
eral complete heat cycles.
Part Number 550-142-304/1220
VISUALLY CHECK - is ground wire connected from
"GND (Burner)" to ignition control mounting screw;
and ground wire connected from transformer Termi-
nal "C" to case ground?
No
Is 24VAC present across Terminals 24V and 24V(GND)
No
Replace pilot assembly.
Yes
Replace ignition control.
Yes
Yes
Open thermostat contacts for 15 seconds. Close thermostat
contacts -
Is 24VAC across terminals PV & MV/PV?
No
Turn OFF supply voltage.
Check spark wire. Is it securely connected
to spark transformer?
No
Is condition of spark wire good (not cut,
brittle, burned, or cracked)?
No
Is spark electrode ceramic cracked?
No
Replace pilot assembly, turn ON supply
voltage, operate system several complete
heat cycles.
Is the vent damper
plug in place?
Yes No
?
Replace damper
plug and retest.
Yes
Yes
Yes
Yes
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