Inspecting Burners; Cleaning And Maintenance - Desa HD18NRA Owner's Operation And Installation Manual

Check pilot flame pattern and burner flame
patterns often.
pILOT FLAME pATTERN
Figure 30 shows a correct pilot flame pattern.
Figure 31 shows an incorrect pilot flame pat-
tern. Incorrect pilot flame is not touching ther-
mocouple. This will cause the thermocouple
to cool. When thermocouple cools, heater
will shut down.
If pilot flame pattern is incorrect, as shown
in Figure 30
• turn heater off (see To Turn Off Gas to
Appliance, page 20
• see Troubleshooting, page 24
Note: Pilot flame on natural gas units will have
a slight curve, but flame should be blue and
have no yellow or orange color.
Thermocouple
Figure 29 - Correct Pilot Flame Pattern
WARNING: Turn off heater
and let cool before cleaning.
CAUTION: You must keep
control areas, burner and circu-
lating 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 clean-
ing due to excessive lint from
carpeting, bedding material, pet
hair, etc.
WARNING: Failure to keep
the primary air opening(s) of
the burner(s) clean may result in
sooting and property damage.
22

INSPEcTING BURNERS

Pilot Burner

cLEANING AND MAINTENANcE

www.desatech.com
Thermocouple
Figure 30 - Incorrect Pilot Flame Pattern
BURNER pRIMARY AIR HOLES
Air is drawn into burner through holes in fit-
ting at entrance to burner. These holes may
become blocked with dust or lint. Periodically
inspect these holes for any blockage and
clean as necessary. Blocked air holes will
create soot.
MAIN BURNER
Periodically inspect all burner flame holes
with 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.
ODS/pILOT AND BURNER
Use a vacuum cleaner or small, soft bristled
brush to clean.
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 and lint. 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 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
directions on can. If you don't follow directions
on can, you could damage pilot assembly.
Pilot Burner
123167-01D