Landa ENG4-2000 Operator's Manual page 23

PROBLEM
FLOW & BURNER
SWITCH ON;
NO SPARK,
NO PILOT GAS
HAVE SPARK,
NO PILOT
GAS FLOW
HAVE PILOT
GAS, NO
SPARK
TROUBLESHOOTING
POSSIBLE CAUSE
A. No main power
B. Faulty transformer
C. Faulty burner & flow switch
D. Faulty ignition control unit
Main gas supply turned off
A. Defective ignitor/
sensor and or its wiring
B. Faulty ignition control unit
ENG • 9.801-511.0 • Rev. 9/13a
SOLUTION
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.
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.
Set test meter to ohm scale.
1. Disconnect the wire from the IGN terminal on
the 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.
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