www.desatech.com
121486-01F
22
INSPECTING HEATER
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.
Pilot Burner
Thermocouple
Figure 38 - Correct Pilot Flame Pattern
(Your pilot may vary from pilots shown)
Pilot Burner
Thermocouple
Figure 39 - Incorrect Pilot Flame Pattern
(Your pilot may vary from pilots shown)
CLEANING AND MAINTENANCE
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
Appliance
, page 19)
• see
Troubleshooting
, page 24
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.
WARNING: Turn off heater
and let cool before cleaning.
CAUTION: You must keep
control areas, burners, and
circulating air passageways
of heater clean. Inspect these
areas of heater before each use.
Have heater inspected yearly
by a qualified service person.
Heater may need more frequent
cleaning due to excessive lint
from carpeting, pet hair, bedding
material, etc.
WARNING: Failure to keep
the primary air opening(s) of
the burner(s) clean may result in
sooting and property damage.
BURNER INjECTOR HOLDER AND
PILOT AIR INLET HOLE
The primary air inlet holes allow the proper
amount of air to mix with the gas. This pro-
vides a clean burning flame. Keep these
holes clear of dust, dirt, lint, and pet hair.
Clean these air inlet holes prior to each
heating season. Blocked air holes will create
soot. We recommend that you clean the unit
every three months during operation and
have heater inspected yearly by a qualified
service person.
We also recommend that you keep the burner
tube and pilot assembly clean and free of dust
and dirt. To clean these parts we recommend
using compressed air no greater than 30 PSI.
Your local computer store, hardware store, or
home center may carry compressed air in a
can. If using compressed air in a can, please
follow the directions on the can. If you don't
follow directions on the can, you could dam-
age the pilot assembly.
1. Remove control cover log and front log.
