Inspecting Burner - Desa HDCFTN Owner's Operation And Installation Manual

OPERATING FIREPLACE
Continued
THERMOSTAT
CONTROL OPERATION
The thermostatic control used on this fireplace
differs from standard thermostats. Standard
thermostats simply turn on and off the burner.
The thermostat used on this fireplace senses the
room temperature. The thermostat adjusts the
amount of gas flow to the burner. This increases
or decreases the burner flame height. At times
the heater will cycle back on when room tem-
perature drops below the set temperature.
The control knob can be set to any heat level
between HI and LO.
Note: The thermostat sensing bulb measures
the temperature of air near the fireplace
cabinet. This may not always agree with
room temperature (depending on housing
construction, installation location, room size,
open air temperatures, etc.). Frequent use of
your fireplace will let you determine your own
comfort levels.
MANUAL LIGHTING
PROCEDURE
1. Follow steps 1 through 5 under Lighting
Instructions, page 20.
2. With control knob pressed in, strike match.
Hold match to pilot until pilot lights.
3. 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 20.

INSPECTING BURNER

Check pilot flame pattern and burner flame pat-
tern often.
PILOT FLAME PATTERN
Figure 32 shows a correct pilot flame pattern.
Figure 33 shows an incorrect pilot flame pattern.
The incorrect pilot flame is not properly heating the
thermocouple. This will cause the thermocouple to
cool. When the thermocouple cools, the fireplace
will shut down.
If pilot flame pattern is incorrect, as shown in
Figure 33
• turn fireplace off (see To Turn Off Gas to Ap-
pliance, page 20)
• see Troubleshooting, page 23
111044-01F
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 32 - Correct Pilot Flame Pattern
Figure 33 - Incorrect Pilot Flame Pattern
BURNER FLAME PATTERN
Figure 34 shows a correct burner flame pattern.
Figure 35 shows an incorrect burner flame pattern.
The incorrect burner flame pattern shows sporadic,
irregular flame tipping. The flame should not be
dark or have an orange/reddish tinge.
Note: When using the fireplace the first time, the
flame will be orange for approximately one hour
until the log cures.
If burner flame pattern is incorrect, as shown in
Figure 35
• turn fireplace off (see To Turn Off Gas to Ap-
pliance, page 20)
• see Troubleshooting, page 23
Figure 34 - Correct Burner Flame Pattern
Figure 35 - Incorrect Burner Flame
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Thermocouple
(Propane/LP Shown)
Pilot Burner
Thermocouple
(Propane/LP Shown)
Pattern
21