P/N 474131
Rev. D 27-06-11
42
Burner Troubleshooting
SYMPTOM
CAUSE
REMEDY
Loud, high-pitched whine
Flame is too rich.
Verify pressure tap between gas valve
and blower inlet.
See page 14 and verify that the gas
regulator setting is 11 ± 5 Pa.
Flame is “fluttery .”
Flame is too lean.
See page 14 and verify that the gas
Exhaust may have acrid
regulator setting is 11 ± 5 Pa.
smell or burner may fail
to stay lit.
Combustion appears
Flame current is not
Check for wet or damaged igniter with
normal, but flame does
being sensed.
low resistance to ground. Replace with
not stay lit.
new igniter.
Verify burner flameholder is properly
grounded.
Ignition Control Module.
Heat Exchanger Troubleshooting
SYMPTOM
CAUSE
REMEDY
Boiling in heat exchanger.
Low water flow to heater.
pump and or filter.
May be accompanied by
Heat exchanger plugged.
Service
Service
heat exchanger. Correct water
“bumping” sounds.
chemistry.
Bypass valve stuck open.
Service bypass valve.
Thermal governor stuck
Replace
Replace
Replace
Contact a qualified technician or service
agency to replace the gas orifice.
Contact a qualified technician or service
agency to replace the gas orifice.
thermal governor.
closed.
Sweating.
Thermal governor failed.
thermal governor.
Section 5. Troubleshooting