Inspecting Burners - Desa H18N Owner's Operation And Installation Manual

Check pilot flame pattern and burner flame
patterns often.
PILOT FLAME PATTERN
Figure 38 shows a correct pilot flame pattern.
Figure 39 shows an incorrect pilot flame pat-
tern. The incorrect pilot flame is not touching
the thermocouple. This will cause the thermo-
couple to cool. When the thermocouple cools,
the heater will shut down.
If pilot flame pattern is incorrect, as shown
in Figure 39
• turn heater off (see To Turn Off Gas to Ap-
pliance, page 21 or page 24)
• see Troubleshooting, page 28
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.
Pilot Burner
Figure 38 - Correct Pilot Flame Pattern
(Your pilot may vary from pilots shown)
26

INSPECTING BURNERS

Thermocouple
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Pilot Burner
Figure 39 - Incorrect Pilot Flame Pattern
(Your pilot may vary from pilots shown)
BURNER PRIMARY AIR HOLES
Air is drawn into the burner through the holes
in the fitting at the burner entrance. These
holes may become blocked with dust or lint.
Periodically inspect these holes for any block-
age and clean if needed. Blocked air holes
will create soot.
MAIN BURNER
Periodically inspect all burner flame holes with
the heater running. All slotted burner flame
holes should be open with yellow flame pres-
ent. All round burner flame holes should be
open with a small blue flame present. Some
burner flame holes may become blocked by
debris or rust, with no flame present. If so,
turn off heater and let cool. Remove blockage.
Blocked burner flame holes will create soot.
Thermocouple
110399-01J