Desa CBN20T EN - Manual (Page 16)

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MANUAL LIGHTING
PROCEDURE
1. Remove front panel (see Figure 7, page 9).
2. Follow steps 1 through 5 under Lighting
Instructions, page 14.
3. With control knob pressed in, strike match.
Hold match to pilot until pilot lights.
4. Keep control knob pressed in for 30 seconds
after lighting pilot. After 30 seconds, release
control knob. Now follow step 8, under
Lighting Instructions, page 14.
5. Replace front panel.
INSPECTING HEATER
Check pilot flame pattern and burner flame pat-
tern often.
PILOT FLAME PATTERN
Figure 21 shows a correct pilot flame pattern. Figure
22 shows an incorrect pilot flame pattern. The incor-
rect pilot flame is not touching the thermocouple.
This will cause the thermocouple to cool. When the
thermocouple cools, the heater will shut down.
If pilot flame pattern is incorrect, as shown in
Figure 22
• turn heater off (see To Turn Off Gas to Appli-
ance, page 15)
• see Troubleshooting, page 19
Note:
The pilot flame on natural gas units will
have a slight curve, but flame should be blue and
have no yellow or orange color.
OPERATING HEATER
Continued
Figure 22 - Incorrect Pilot Flame Pattern
Figure 21 - Correct Pilot Flame Pattern
Thermocouple
Pilot Burner
Pilot Burner
Thermocouple
Blue Flame
Yellow Flame
BURNER FLAME PATTERN
WARNING: If yellow tipping
occurs, your heater could pro-
duce increased levels of carbon
monoxide.
NOTICE: Do not mistake orange
flames with yellow tipping. Dirt
or other fine particles enter the
heater and burn causing brief
patches of orange flame.
Figure 23 shows a correct burner flame pattern.
Figure 24 shows an incorrect burner flame pattern.
The incorrect burner flame pattern shows yellow
tipping of the flame. It also shows the flame higher
than 1/2 the glass panel height.
If burner flame pattern is incorrect, as shown in
Figure 24
• turn heater off (see To Turn Off Gas To Appli-
ance, page 15)
• see Troubleshooting, page 19
1/2 GLASS HEIGHT
CORRECT FLAME PATTERN
AT HIGH POSITION
INCORRECT FLAME PATTERN
AT HIGH POSITION
1/2 GLASS HEIGHT
Figure 23 - Correct Burner Flame Pattern
Yellow Tipping
1/2 GLASS HEIGHT
CORRECT FLAME PATTERN
AT HIGH POSITION
INCORRECT FLAME PATTERN
AT HIGH POSITION
1/2 GLASS HEIGHT
Figure 24 - Incorrect Burner Flame
Pattern
1/2 Glass
Height
Blue
Flame
1/2 Glass
Height