Desa NTH100 - Manual (Page 9)

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OWNER’S MANUAL
Spark Plug
(35,000 Btu/Hr Model)
1. Remove upper shell (see page 8).
2. Remove fan (see page 13).
3. Remove fuel and air line hoses from
nozzle assembly.
4. Remove spark plug wire from spark plug.
5. Remove two screws using 5/16" nut-
driver and remove burner strap.
6. Place hex-body of spark plug into vise
and tighten.
7. Remove spark plug mounting nut us-
ing 11/16" open-end wrench.
8. Remove burner strap from spark plug.
9. Clean and regap spark plug electrodes
to 1.4 mm (.055") gap.
10. Replace burner strap onto spark plug.
Rotate burner strap to position spark
plug electrodes (see Figure 13).
11. Tighten spark plug with spark plug
mounting nut.
12. Release hex-body of spark plug from
vise.
13. Replace burner strap onto combustion
chamber.
14. Attach spark plug wire to spark plug.
15. Attach fuel and air line hoses to nozzle
assembly.
16. Replace fan (see page 13).
17. Replace fan guard and upper shell.
Figure 13 - Spark Plug Rotation, 35,000
Btu/Hr Model Only
Figure 12 - Spark Plug Gap, 35,000 Btu/Hr
Model
Figure 11 - Spark Plug Removal, 35,000
Btu/Hr Model
SERVICE
PROCEDURES
Continued
Continued
Combustion
Chamber
Burner Strap
Nozzle
Assembly
Fuel Line
Hose Air Line
Hose
Spark Plug
Mounting Nut
Spark Plug
Spark
Plug
Wire
Bend Here
to Adjust
Gap
1.4 mm
(.055")
Gap
Burner
Strap Burner
Strap
Spark Plug
(50/70/100/150,000 Btu/Hr Models)
1. Remove upper shell (see page 8).
2. Remove fan (see page 13).
3. Remove spark plug wire from spark plug.
4. Remove spark plug from burner head
using 13/16" open-end wrench.
5. Clean and regap spark plug electrodes
as follows:
50/70/100,000 Btu/Hr Models:
1.9 mm (.075") gap
150,000 Btu/Hr Model:
2.8 mm (0.110") gap
6. Install spark plug in burner head.
7. Attach spark plug wire to spark plug.
8. Replace fan (see page 13).
9. Replace fan guard and upper shell.
Figure 14 - Spark Plug Removal, 50/70/
100/150,000 Btu/Hr Models
Burner
Head
Spark
Plug
Wire
Spark
Plug
Figure 15 - Spark Plug Gap, 50/70/100/
150,000 Btu/Hr Models
Bend Here
to Adjust
Gap
Gap