Page 28
Troubleshooting: Burner starts and fires, but lock out on safety.
Source
Procedure
Causes
Correction
Poor Fire
After burner
fires, immedi-
ately jumper
across flame
detector termi-
nals at the pri-
mary control.
If burner con-
tinues to run,
this may be
due to poor
fire. Inspect
fire.
Unbalanced fire
Replace nozzle
Too much air − −lean short fire
Reduce combustion air − check
combustion.
Too little air − − long dirty fire
Increase combustion air − check
combustion.
Excessive draft
Adjust barometric draft control
for correct draft.
Too little draft or restriction
Correct draft or remove restric-
tion.
Flame Detector
If fire is good,
fault is in the
flame detector.
Check detec-
tor circuit.
Faulty cad cell (open circuit)
Replace cad cell.
Loose connections or broken
cad cell wires
Secure connections or replace
cad cell holder and wire leads.
Cad cell cannot sense flame
Check cad cell for proper align-
ment. Check cad cell face and
clean, if necessary.
Primary Control
If burner locks
out on safety,
fault is in the
primary con-
trol.
Primary control circuit failed
Replace primary control.
Troubleshooting: Burner Starts and Fires, but Loses Flame and Lock Out on Safety
Source
Procedure
Causes
Correction
Poor Fire
After burner
fires, immedi-
ately jumper
across flame
detector termi-
nals at the pri-
mary control.
If burner con-
tinues to run
(does not lock
out of safety),
fault may be
due to poor
fire. Inspect
fire.
Unbalanced fire
Replace nozzle
Too much air − − lean short fire
Reduce combustion air − check
combustion.
Too little air − − long dirty fire
Increase combustion air − check
combustion.
Excessive draft
Adjust barometric draft control
for correct draft.
Too little draft or restriction
Correct draft or remove restric-
tion.
Flame Detector
If fire is good,
fault is in the
flame detector.
Check detec-
tor circuit.
Faulty cad cell (open circuit)
Replace cad cell.
Loose connections or broken
cad cell wires
Secure connections or replace
cad cell holder and wire leads.
Cad cell cannot sense flame
Check cad cell for proper align-
ment. Check cad cell face and
clean, if necessary.
Oil Supply
If burner loses
flame (does
not lock out on
safety), fault is
in the fuel sys-
tem.
Pump loses prime − air slug
Prime pump at bleed port
Pump loses prime − air leak in
supply line
Check supply line for loose con-
nections and tighten fittings.
Water slug in line
Check oil tank for water (over 1
inch) pump or drain out water.
Partially plugged nozzle or
nozzle strainer
Replace nozzle.
Listen for pump whine
Restriction in oil line
Clear restriction.
Plugged fuel pump strainer
Clean strainer or replace pump.
Cold oil − outdoor tank
Change to number 1 oil.
