Desa RH125TH Owner's Manual page 12

SERVICE PROCEDURES
12
SERVICE PROCEDURES
Continued
PUMP ROTOR
(Procedure if Rotor is Binding)
1. Remove upper shell (see Upper Shell Removal, page 8).
2. Remove fan guard.
3. Remove filter end cover screws using 5/16" nut driver (see
Figure 18).
4. Remove filter end cover and air filters.
5. Remove pump plate screws using 5/16" nut-driver.
6. Remove pump plate.
7. Remove rotor, insert, and blades (see Figure 18).
8. Check for debris in pump. If debris is found, blow out with
compressed air.
9. Install insert and rotor.
10. Check gap on rotor. Adjust to .003"/.004" (.076/.101 mm) if
needed (see Figure 19).
Note: Rotate rotor one full turn to ensure the gap is .003"/.004"
(.076/.101 mm) at tightest position. Adjust if needed.
11. Install blades, pump plate, air filters, and filter end cover.
12. Replace fan guard and upper shell (see Upper Shell Removal,
page 8).
13. Adjust pump pressure (see Pump Pressure Adjustment, page 9).
Note: If rotor is still binding, proceed as follows.
Rotor
Insert
Air Output
Filter
Figure 18 - Rotor Location
Gap Adjusting Screw
Blade
Gap Adjusting Screw
Figure 19 - Gap Adjusting Screw Locations
Blade
Pump Plate
Air Intake
Filter
Filter End
Cover
.003"/.004"
(.076-.101 mm)
Gap Measured
With Feeler
Gauge
Rotor
For more information, visit www.desatech.com
For more information, visit www.desatech.com
14. Perform steps 1 through 6.
15. Place fine grade sandpaper (600 grit) on flat surface. Sand ro-
tor lightly in "figure 8" motion four times (see Figure 20).
16. Reinstall insert and rotor.
17. Perform steps 10 through 12.
Sandpaper
Figure 20 - Sanding Rotor
IGNITION CONTROL ASSEMBLY
WARNING: High voltage!
1. Unplug heater.
2. Remove control cover screws (2) using phillips screwdriver to
expose ignition control assembly (see Figure 11, page 9).
3. Remove fuse cover.
4. Remove fuse from fuse clips.
5. Replace with new fuse (DESA Heating Products part number
105880-02). Do not substitute a fuse with a higher current rat-
ing. Use Bussmann GMA-10 or equivalent.
6. Replace fuse cover.
7. Replace control cover (see Figure 11, page 9).
Fuse Clips
Figure 21 - Replacing Fuse
Fuse Cover
Fuse
112865-01A