H I G H P R E S S U R E P O R T A B L E F O R C E D A I R H E A T E R S E R V I C E M A N U A L
13
C. Incorrect fuel pump pressure
1. Install pressure gage to fuel pump port
marked “GAGE.” This gage should have
a full scale reading of 150-200 psi.
2. Connect heater to electrical power to test
fire heater.
3. Adjust pump pressure by turning slotted
screw at fuel pump port marked “PRESS
ADJ.” Turn screw clockwise to increase
pressure. Turn screw counterclockwise
to decrease pressure. See HEATER PER-
FORMANCE SPECIFICATIONS on page
6 for proper fuel pump pressure.
D. Dirty or damaged nozzle
1. Remove upper shell of heater.
2. Remove burner head from combustion
chamber.
3. Remove nozzle from burner head.
4. If nozzle is dirty, do not attempt to clean
by inserting wire into orifice opening.
Soak nozzle in a non-flammable solvent
and use compressed air to dislodge any
dirt in nozzle. Replace worn or damaged
nozzle with new nozzle.
POSSIBLE CAUSES
A. Poor fuel quality
B. Spark plug tip is too close to spray pattern
of nozzle
C. Incorrect fuel pump pressure
D. Dirty or damaged nozzle
TEST PROCEDURES
A. Poor fuel quality
Use good quality fuel. See GENERAL SPECI-
FICATIONS AND APPLICATIONS INFOR-
MATION, page 5, for fuel guidelines.
B. Spark plug tip is too close to spray
pattern of nozzle
1. Remove upper shell of heater.
2. Remove spark plug from burner head.
3. Clean and regap spark plug. Correct gap
for spark plug is .05/.06 inch.
4. Install plug in burner head.
5. Replace upper shell on heater.
6. Connect heater to electrical supply to test
fire heater.
7. Shut heater off, unplug heater, and re-
move spark plug to determine if electrode
is wet. If electrode is wet, place a 0.1"
metal washer/spacer between burner
head and spark plug. This will keep the
plug out of the spray pattern of nozzle.
8. Retest heater. Install additional metal
washer(s)/spacer(s) if needed.
psi
Figure 14 - Checking Fuel Pump Pressure
1/4 NPT
(Pipe) Threads
Figure 13 - Adding Metal
Washer/Spacer to Spark Plug
Figure 15 - Nozzle
TROUBLESHOOTING — PROBLEM CONDITIONS
OBSERVED PROBLEM
Frequent spark plug fouling/delayed ignition
