Weil-McLain Boiler - Manual (Page 30)

0 Part Number 550-110-646/0607
EG • PEG • EGH Series 4
Troubleshooting
continued
No Yes
Does spark stay on for more than a few seconds after pilot is established?
No Yes
Is 24VAC between terminals MV and
PV on ignition control?
Replace
ignition control.
No Yes
Make sure sense wire is not wrapped around any pipes or
accessories.
Is sense wire securely attached to sense terminal and pilot
assembly?
Correct.
No Yes
Is sensing probe ceramic
cracked?
Replace pilot
assembly.
No Yes
Is sense wire or sensing probe
shorted out to a metal surface?
Correct.
No Yes
Check sense wire continuity.
Check condition of insulation.
Both OK?
Replace pilot
assembly.
Replace ignition control.
Check for proper gas pressure.
Clean pilot assembly.
Tighten mechanical and electrical connections.
Check for proper system grounding.
See procedure to check grounding on next page. •
•
•
•
•
No Yes
Set up microammeter to measure output current in flame
sensor circuit as follows:
a. Detach sense lead from ignition control. Attach
negative lead from microammeter to sense terminal on
ignition control.
b. Attach positive lead to sense wire from pilot assembly.
c. Disconnect main valve lead from terminal “MV” on
ignition control.
d. Energize the system. Spark should ignite the pilot. As
soon as pilot is burning, the microammeter should read
at least 1.0 microamp for Honeywell S8620C control,
or 0.1 microamp for United Technologies 1003-611A
control.
e. Is flame current signal less than the minimum specified
in step “d” above?
Does system have proper flame signal?
No Yes
Check inlet gas pressure. Is pressure:
at least 5.0 inches w.c.?
not more than 14.0 inches w.c.?
•
•
No Yes
Is main valve wiring secure at
terminals?
Contact gas
supplier to
correct pressure.
CHART 3: PILOT LIGHTS — Main valve will not come on — With or without vent damper
Correct wiring.
Replace gas
valve.