A.O. Smith 200M - Manual (Page 25)

25
CHART 2
S8600 (NATURAL GAS AND LP GAS)
INTERMITTENT PILOT SYSTEM TROUBLESHOOTING
NO SPARK AT PILOT BURNER
Turn gas supply off.
Is voltage (24 Vac) across the 24 V terminals on “Call for heat”?
Is voltage (24 Vac) across the PV & MV/PV terminals on
“call for heat”?
NOTE: (FOR LP MODELS ONLY) Pilot valve will be de-energized
if module goes into lockout condition. Reset system by turning
electrical power off or by turning system controller to “OFF” or
down below “Call for heat”. Wait one minute then turn system on.
Turn off power supply.
Is ignition cable firmly plugged into module?
Is green ground wire firmly attached to mounting screw
and GND terminal on module?
Ensure ground strap is the closest metal to the igniter/sensor
rod (electrode) to prevent the spark from shorting out
to other metal parts (pilot screen, pilot shield, etc.).
Ignition cable must not touch metal surfaces or
current carrying wires.
Is there a 1/8” gap between ground strap and electrode?
Are the ceramic insulators surrounding the electrode
cracked or broken?
Replace pilot burner assembly or bus bar.
Replace ignition module.
Turn on gas supply.
turn on power supply.
Securely connect cable
and/or ground wire.
Carefully bend downward
top of ground strap
to achieve 1/8”
spark gap.
Replace ignition
module.
YES
NO
YES
YES
YES
YES
NO
NO
NO
NO