OM/SM-TDH-CE
SYMPTOM
WHO
WHAT TO CHECK
16
System does not produce a
spark.
Auth
Service
Rep Only
a.
Thermostat, and close the contacts, if they are open.
b.
AC voltage between terminals “1" and GND. If it is not 230
VAC, check the high limit switch, which should be closed
c.
Pilot spark gap. Regap, if it is not 7/64 inch (2.78 mm).
d.
Electrode ceramic for crack or break.
e.
That the high tension cable is firmly attached and in good
condition. If it is cracked or brittle, replace the pilot.
f.
Replace the electronic spark ignition module.
Spark is present, but the pilot
will not light.
Auth
Service
Rep Only
a.
That the gas valve is opening.
b.
That gas pressure meets the control manufacturer’s
specifications.
c.
For gas at the pilot. If it is not flowing:
(1)
Check the pilot gas line for kinks and obstructions.
(2)
Replace the gas control valve.
d.
That the pilot spark gap is 7/64 inch (2.78 mm) and located in
the pilot gas stream. If not, adjust or replace the pilot.
e.
Orifice, and clean, if necessary
Pilot lights, but main burner
will not come on, and the
spark stays on.
Auth
Service
Rep Only
a.
Sensor cable, to make sure of secure attachment to terminal
“1" on module and to the sensor.
b.
Sensor ceramic for cracks.
c.
That the cable is not grounded out. If it is, correct the ground.
d.
Sensor cable for continuity and condition of insulation.
e.
(1)
Check the gas pressure.
(2)
Clean the pilot assembly.
(3)
Tighten mechanical and electrical connections.
Pilot lights, but main burner
will not come on, and spark
does not stay on.
Auth
Service
Rep Only
a.
That gas pressure meets the control manufacturer’s
specifications.
b.
Replace spark ignition module.
Main burner comes on but will
not stay lit.
Auth
Service
Rep Only
a.
Check burner ground for bad wire or connection. Replace with
high temperature wire if necessary.
b.
Check for low gas supply pressure. If necessary, replace
ignition control module.
c.
Ceramic insulator or pilot flame sensor cracked. Replace
flame sensor.
