A.O. Smith 160M Operation Manual page 26

INTERMITTENT PILOT SYSTEM TROUBLESHOOTING
SPARK AT PILOT BURNER BUT PILOT WILL NOT LIGHT
Attach wires firmly.
Replace gas valve.
Turn on power supply
Securely connect
cable and/or ground
wire.
Replace pilot burner
and/or ground wire.
Carefully bend down-
wards top of ground
strap to achieve
1/8" spark gap.
Replace pilot burner.
Replace ignition
module.
CHART 2
S8600 (NATURAL GAS AND LP GAS)
Ensure all manual shutoff valves are fully open; All filters are
clean; All gas connections are gas tight; Pilot tubing is not
damaged, obstructed or kinked; and pilot orifice is unclogged.
Check for air in gas line, purge (bleed) line if necessary.
NO
Are the wires securely attached to the pilot operator on the gas
control and to the PV & MV/PV terminals on the ignition module?
Install a pressure gauge in the pilot tubing line between the gas
control and the pilot burner assembly. Ensure that the pilot
NO
adjustment screw (under cap) is adjusted to a position that will
Is ignition cable firmly plugged into module?
NO
Is green ground wire firmly attached to mounting screw
NO
Is pilot burner ignition cable in good condition (not brittle, burnt, or cracked)?
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.).
NO
Ignition cable must not touch metal surfaces or
Is there a 1/8" gap between ground strap and electrode?
NO
Are the ceramic insulators surrounding the electrode in good
NO
Is there excessive draft conditions that may cause pilot
Correct draft problems in a manner that would ensure
adequate combustion and ventilation air and proper
26
YES
permit gas to flow.
Is pilot gas flowing during ignition attempt?
YES
Turn off power supply.
and GND terminal on module?
YES
YES
current carrying wires.
YES
condition (not cracked or broken)?
YES
burner ignition problems?
YES
pilot burner performance.