Troubleshooting - Heat & Glo MEZZO36 Owner's Manual

B. Troubleshooting
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 qualifi ed service technician in the diagnosis of a problem and
the corrective action to be taken. This troubleshooting guide can only be used by a qualifi ed service technician. Contact
your dealer to arrange a service call by a qualifi ed service technician.
IntelliFire™ Plus Ignition System
Symptom
1. Pilot won't light. A. Incorrect wiring.
The ignitor/module
makes noise, but no
B. Loose connections or electrical
spark.
C. Ignitor gap is too large.
2. Pilot won't light, A. No power, transformer installed
there is no noise or
spark.
B. A shorted or loose connection in
C. Improper wall switch wiring.
D. Module not grounded.
3. Pilot sparks, but A. Gas supply.
Pilot will not light.
B. Ignitor gap is too large.
C. Module is not grounded.
D. Pilot valve solenoid.
Heat & Glo • MEZZO36, MEZZO36ST, MEZZO48, MEZZO48ST Owner's Manual • 2300-971 Rev. B • 5/14
Possible Cause
shorts in the wiring.
incorrectly, or depleted batteries.
wiring confi guration or wiring har-
ness.
Corrective Action
Verify "S" wire (white) for sensor and "I" wire (orange) for ignitor are
connected to correct terminals on module and pilot assembly.
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 fl ame sense wires are not grounding
out to metal chassis, pilot burner, pilot enclosure, mesh screen if
present, or any other metal object.
Verify gap of igniter to right side of pilot hood. The gap should be
approximately .17 in. or 1/8 in. (3 mm).
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.
Remove and reinstall the wiring harness that plugs into module.
Verify there is a tight fi t. Verify pilot assembly wiring to module. Re-
move and verify continuity of each wire in wiring harness. Replace
any damaged components.
Verify that 110-120 VAC power is "ON" to junction box.
Verify black ground wire from module wire harness is grounded to
metal chassis of appliance.
Verify that incoming gas line ball valve is "open". Verify that inlet
pressure reading is within acceptable limits.
Verify gap of igniter to right side of pilot hood. The gap should be
approximately .17 in. or 1/8 in. (3 mm).
Verify module is securely grounded to metal chassis of appliance.
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.
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