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Heatilator • NNXT4236IF-B, NNXT4236ILF-B, NNXT3933IF-B, NNXT3933ILF- B Owner’s Manual • 2384-981 Rev. G • 6/18
With proper installation, operation, and maintenance your gas appliance will provide years of trouble-free service. If you do
experience a problem, this troubleshooting guide will assist a qualified service technician in the diagnosis of a problem and
the corrective action to be taken. This troubleshooting guide can only be used by a qualified service technician. Contact
your dealer to arrange a service call by a qualified service technician.
B. Troubleshooting
IntelliFire™ Plus Ignition System
Symptom
Possible Cause
Corrective Action
1. Pilot won’t light.
The ignitor/module
makes noise, but no
spark.
A. Incorrect wiring.
Verify “S” wire (white) for sensor and “I” wire (orange) for ignitor are
connected to correct terminals on module and pilot assembly.
B. Loose connections or electrical
shorts in the wiring.
Verify no loose connections or electrical shorts in wiring from mod-
ule to pilot assembly. Verify connections underneath pilot assembly
are tight; also verify igniter and flame sense wires are not grounding
out to metal chassis, pilot burner, pilot enclosure, mesh screen if
present, or any other metal object.
C. Ignitor gap is too large.
Verify gap of igniter to right side of pilot hood. The gap should be
approximately .095 in. (2.41 mm) to .135 in. (3.43 mm).
2. Pilot won’t light,
there is no noise or
spark.
A. No power, transformer installed
incorrectly, or depleted batteries.
Verify that transformer is installed and plugged into module. Check
voltage of transformer at connection to module. Acceptable read-
ings of a good transformer are between 6.4 and 6.6 volts DC. Bat-
tery power supply voltage must be at least 4 volts. If less than 4
volts, replace batteries.
B. A shorted or loose connection in
wiring configuration or wiring har
-
ness.
Remove and reinstall the wiring harness that plugs into module.
Verify there is a tight fit. Verify pilot assembly wiring to module. Re
-
move and verify continuity of each wire in wiring harness. Replace
any damaged components.
C. Improper wall switch wiring.
Verify that 110-120 VAC power is “ON” to junction box.
D. Module not grounded.
Verify black ground wire from module wire harness is grounded to
metal chassis of appliance.
3. Pilot sparks, but
Pilot will not light.
A. Gas supply.
Verify that incoming gas line ball valve is “open”. Verify that inlet
pressure reading is within acceptable limits.
B. Ignitor gap is too large.
Verify gap of igniter to right side of pilot hood. The gap should be
approximately .095 in. (2.41 mm) to .135 in. (3.43 mm).
C. Module is not grounded.
Verify module is securely grounded to metal chassis of appliance.
D. Pilot valve solenoid.
Verify that 1.5 to 1.8 VDC is supplied to pilot solenoid from module.
If below 1.5 volts, replace module. If 1.5 volts or greater, replace
valve.