28
Maintenance
PROBLEM
POSSIBLE CAUSE
SOLUTION
FLOW & BURNER
SWITCH ON;
NO SPARK,
NO PILOT GAS
A. No main power
B. Faulty transformer
C. Faulty burner & flow switch
D. Faulty ignition control unit
With power switch on, open trigger on spray gun
and set your test meter to the 24 volt scale. Probe
terminals 24V and 24V(GND). If you do not read 24
volts, the problem is not the ignition system.
Perform normal system checks of main power,
transformer, thermostat and the limit control. If you
do read 24 volts at TH and GND, the problem is in
the ignition system. Check for loose or defective
wiring. If wiring is good, replace the ignition control
unit.
HAVE SPARK,
NO PILOT
GAS FLOW
Main gas supply turned off
Set test meter to 24 volt scale.
1. Be sure main gas valve (gas cock or selector
arm) is turned on.
2. With gas on and system sparking, probe
terminals PV and 24V(GND). If pilot gas does not
flow with 24 volts at these terminals, replace gas
valve.
3. Probe terminals PV and MV/PV. If 24 volts not
present, replace ignition control box.
HAVE PILOT
GAS, NO
SPARK
A. Defective ignitor/
sensor and or its wiring
Set test meter to ohm scale.
1. Disconnect the wire from the IGN terminal on the
ignition control unit.
B. Faulty ignition control unit
2. Touch one meter probe to the tip of the ignitor/
sensor rod in the pilot. Touch the other probe to the
quick connect at the other end of ignitor/sensor
wire.
3. If you have continuity from the tip of the ignitor/
sensor rod to the connector and no spark, replace
the ignition control unit.
4. If you do not have continuity through wire and the
ignitor/sensor, check for a loose wire connection in
the wire. Repair as needed.
5. Check to see if spark shorts to burner ring
through a cut in the ignitor wire.
MANUAL, OPERATOR, HOTSY, STAT ELEC NG-LP 9.808-037.0-A
