Coleman P*HBX12F08001 Installation Instructions Manual page 15

PROBLEM
Oil burner sputtering at
nozzle
Excessive fuel oil con-
sumption
Too much smoke
Furnace will not warm
home to desired tempera-
ture
Home does not heat
evenly
Supply air temperature too
hot
Supply air temperature too
cool
Unitary Products Group
SYSTEM TROUBLESHOOTING - CONT'D
POSSIBLE CAUSE
Electrodes out of adjustment
or defective
Poor transformer high voltage
connections or defective
transformer
Fuel oil filter clogged
Defective oil pump
Fuel oil line partially clogged
or contains air
System temperature rise too
high
Blower fan control out of ad-
justment, (fan stops too soon)
Fuel oil leak
Stack temperature too high.
Thermostat improperly ad-
justed or in poor location.
Insufficient combustion air
adjustment at oil burner, or
improper draft pressure
Heat exchanger partially
clogged
Air flow blocked by dirty air
filter
Thermostat adjustments or
location
Insufficient air flow
Defective high limit control
Under-sized nozzle.
Blower fan motor stopping in-
termittently on overload
Burner motor stopping inter-
mittently on overload
Improper distribution of heat This is not likely to be furnace problem. Balance duct system.
Air flow blocked or dirty air fil-
ter
Insufficient air flow
Fan control "fan on" setting
too low
Excessive duct losses
Check electrode settings. Check electrodes for dirt build-up or
cracks in porcelain.
Check contacts between transformer and electrodes. If OK, replace
transformer.
Replace fuel oil storage tank filter and/or fuel oil in-line filter
Check burner motor/fuel oil pump coupling. Check oil pump pres-
sure. Replace fuel oil pump if necessary.
Bleed air from oil line. If problem persists, replace oil line.
System temperature rise should not exceed 85° F. Check for
clogged air filters. Check blower fan for excess dirt build-up or de-
bris. Speed up blower fan if necessary.
Check fan control settings. The fan control is adjusted with a duct
thermometer in the supply air plenum take-off or first few inches of
the supply air trunk duct. The "fan off" setting should be 90° - 100° F.
Once set, the "fan on" setting is normally adjusted 25° -30° F higher
than the "fan off" setting.
Check fuel oil line for leaks. Repair or replace if necessary.
Check stack temperature. Stack temperature will normally range
from 350° to 450° F. Check draft regulator. Draft should be set to
0.02" WC.
Check thermostat heat anticipator setting against measured amper-
age draw. Increase heat anticipator setting if necessary. If the ther-
mostat is being influenced by drafts, sunlight, duct work, etc,
relocate to a more suitable location.
Adjust the oil burner combustion air band and draft regulator to gain
the highest CO possible with a Bacharach No.1 smoke.
2
Check for soot build-up in heat exchanger flue passages, especially
in the outer radiator.
Clean or replace air filter
Check thermostat heat anticipator setting against measured amper-
age draw. Increase heat anticipator setting if necessary. If the ther-
mostat is being influenced by drafts, sunlight, duck work, etc,
relocate to more suitable location.
Check all dampers. Open closed dampers including registers in un-
used rooms. Check system temperature rise. If temperature rise is
too high, speed up blower fan.
Test high limit function of all limit switches. Use a duct thermometer
to assess accuracy of limit control. Check for obstructions to air flow
around limit switch bi-metal elements. Replace control if necessary.
Check nozzle. If problem is not caused by air flow problems, use
larger nozzle, if permitted by rating plate.
Check blower fan motor amperage draw. Check motor ventilation
ports, clean if necessary. Replace motor if necessary.
Check burner motor. Replace if necessary.
Clean or replace air filter.
Check all dampers. Open closed dampers including registers in un-
used rooms. Check system temperature rise. If temperature rise is
too high, speed up blower fan.
Check system temperature rise. Slow down blower fan if necessary.
Check supply air duct work. Seal leaky joints and seams. Insulate
ductwork if necessary.
035-14289-000 Rev. A (0701)
REMEDY
15