WARNING: Inspection, testing and repair of electrical equipment should only be performed by a qualified service techni-
cian. Many of the tests require that the unit have power to it and live electrical components be exposed.
USE EXTREME CAUTION WHEN TESTING THE MACHINE.
TROUBLESHOOTING SECTION
18
Possible Cause Action
T-mid thermistor inoperative.
Check T-mid thermistor readings at control
board set points.
T-set too low. Check T-set is at 4.25 VDC.
Obstruction in gas burners or gas nozzles.
Remove burner manifold and check for
obstructions.
Control board damaged. Replace control board.
Incorrect gas nozzles for type of gas being
used.
Remove burner manifold and check correct
nozzle orifice size.
Gas leak may be present.
Check for localized large yellow flame, or a
flame located above the burner.
Obstruction in heat exchanger vent or air
intake.
Check for obstructions.
Flame proofing not occurring.
Check ignition wire. Check that lights
above connection point to DSI are dimly lit
(proofing signal is present).
Failure or incorrect setting of thermostat.
Back thermostat CCW one full turn and
restart unit. When cycle completes, set
thermostat to 170 F (76.67 C) by turning
CW.
Ignition attempt with flame already burning.
Heat exchanger and recirculating pump de-
energize at end of rinse cycle with wash
tank temperature below 170 F (76.67 C).
Exhaust contains dark smoke.
Symptom
The unit ignites, but will to rise above
ignition burn.