035-17473-000-B-1101
26
Unitary Products Group
Furnace starts but cuts out requiring manual resetting the oil protector
reset button.
No fuel oil
Check fuel oil supply. Check that all hand operated
fuel oil valves are in the open position. Fill oil storage
tank if necessary.
Clogged nozzle.
Replace nozzle with high quality replacement. Use rat-
ing plate or Table 2 as a guide.
Clogged oil filter.
Replace oil tank filter or in-line filter if used.
Low oil pump pressure.
Connect pressure gauge to oil pump. Adjust pump
pressure, or replace oil pump if necessary. Ensure that
erratic pressure readings are not caused by defective
fuel oil line.
Air getting into fuel oil lines, or
fuel oil line dirty, clogged, or in
some manner defective.
Check oil fuel lines. Replace any compression fittings
found with high quality flared fittings. Check for any
signs of oil leaks. Any oil leak is a potential source of
air or contaminants.
Defective burner motor.
Check burner motor. If burner motor is cutting out on
over-load, determine why. Replace if necessary.
Water or contaminants in oil.
Drain fuel oil storage tank, replace fuel oil. (Consult
with fuel oil supplier).
Frozen oil line.
Gently warm oil line. Insulate oil line. (Outdoor piping
size may require increase diameter).
Oil burner sputtering at nozzle.
Electrodes out of adjustment or
defective.
Check electrode settings. Check electrodes for dirt
buildup or cracks in porcelain.
Poor transformer high voltage
connections or defective
transformer.
Check contacts between ignition transformer and elec-
trodes. If OK, replace ignition transformer.
Fuel oil filter clogged.
Replace fuel oil storage tank filter and / or fuel oil in-
line filter.
Defective oil pump.
Check burner motor / fuel oil pump coupling. Check oil
pump pressure. Replace fuel oil pump if necessary.
Fuel oil line partially clogged or
contains air.
Bleed air from oil line. If problem persists replace oil
line.
Excessive fuel oil consumption
System temperature rise too
high.
System temperature rise ideally should not exceed
85°F. Check for clogged air filters. Check blower fan
for excess dirt build-up or debris. Speed up blower fan
if necessary.
Poor “fan off” delay timing
selection (fan stops too soon).
Check “fan off” delay timing setting. Use a duct therm-
meter in the supply air plenum take-off or first few
inches of the suply air trunk duct. Ideally, the fan will
shut at a temperature 90° - 100°F. Manipulate the dip
switch settings to come as close as possible to this
“fan off” temperature.
Fuel oil leak.
Check fuel oil line for leaks. Repair or replace if neces-
sary.
Stack temperature too high.
Check stack temperature. Stack temperatures will nor-
mally range from 350° to 450°F. Check draft regulator.
Draft should be set to 0.02 in w.c.
Thermostat improperly adjusted
or in poor location.
Check thermostat heat anticipator setting against
measured amperage draw. Increase heat anticipator
setting if necessary. If the thermostat is being influ-
enced by drafts, sunlight, duct work, etc., relocate to
more suitable location.
Too much smoke.
Insufficient combustion air
adjustment at oil burner, or
improper draft pressure.
Adjust the oil burner combustion air band and draft
regulator to gain the highest practical CO
2
or lowest
practical O
2
content in the flue gases. See Burner Set
Up.
Heat exchanger partially
clogged.
Check for soot build-up in heat exchanger flue pas-
sages, especially in the outer radiator.
Table 12: System & General Troubleshooting (Continued)
