Desa 35 - Manual (Page 6)

6 102388
PORTABLE FORCED AIR HEATERS
35,000, 50,000, And 55,000 Btu/Hr H.S.I. Series
PUMP PRESSURE
ADJUSTMENT
1. Remove pressure gauge plug from filter
end cover.
2. Install accessory pressure gauge (part
number HA1180).
3. Start heater (see Operation, page 4). Al-
low motor to reach full speed.
4. Using a flat blade screwdriver, adjust
pressure. Turn relief valve to right to
increase the pressure. Turn relief valve
to left to decrease the pressure. Set
pump pressure as follows:
35 Model: 3.0 psi
50 Model: 3.6 psi
55 Model: 3.6 psi
5. Remove pressure gauge. Replace pres-
sure gauge plug in filter end cover.
Figure 6 - Pressure Gauge Plug Removal
Figure 7 - Adjusting Pump Pressure
Pressure
Gauge
SERVICE
PROCEDURES
WARNING: Never service
heater while it is plugged in, op-
erating, or hot. Severe burns and
electrical shock can occur.
Figure 3 - Upper Shell Removal
Figure 5 - Air Output, Air Intake, and Lint
Filters
Figure 4 - Fan Cross Section
Upper Shell
Fan
Guard
UPPER SHELL REMOVAL
1. Remove screws along each side of
heater using 5/16" nut-driver. These
screws attach upper and lower shells
together.
2. Lift upper shell off.
3. Remove fan guard.
FAN
IMPORTANT: Remove fan from motor
shaft before removing motor from heater.
The weight of the motor resting on the
fan could damage the fan pitch.
1. Remove upper shell (see above).
2. Use 1/8" Allen wrench to loosen set-
screw which holds fan to motor shaft.
3. Slip fan off motor shaft.
4. Clean fan using soft cloth moistened
with kerosene or solvent.
5. Dry fan thoroughly.
6. Replace fan on motor shaft. Place
fan hub flush with end of motor
shaft (see Figure 4).
7. Place setscrew on flat of shaft.
Tighten setscrew firmly (40-50
inch-pounds).
8. Replace fan guard and upper shell.
Fan
Motor
Flush
Setscrew
Motor
Shaft
Air Intake Filter
Filter End Cover
Fan Guard
Air Output Filter
Lint Filter
AIR OUTPUT, AIR INTAKE,
AND LINT FILTERS
1. Remove upper shell (see Upper Shell
Removal).
2. Remove filter end cover screws using
5/16" nut-driver.
3. Remove filter end cover.
4. Replace air output and lint filters.
5. Wash or replace air intake filter (see
Preventative Maintenance Schedule,
page 4).
6. Replace filter end cover.
7. Replace fan guard and upper shell.
IMPORTANT: Do not oil filters.
Relief Valve
Pressure
Gauge
Plug