Desa CRN30 - Manual (Page 17)

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OPERATING HEATER
Continued
THERMOSTAT
OPERATION
The thermostatic control used on these models
differs from standard thermostats. Standard
thermostats simply turn on and off the burner.
The thermostat used on this heater senses the
room temperature. At times the room may
exceed the set temperature. If so, the burner
will shut off. The burner will cycle back on
when room temperature drops below the set
temperature. The control knob can be set to
any 2 comfort level between HI and LO. All
plaques will turn off and on.
Note:
The thermostat sensing bulb measures
the temperature of air near the heater cabinet.
This may not always agree with room tem-
perature (depending on housing construction,
installation location, room size, open air tem-
peratures, etc.) Frequent use of your heater will
let you determine your own comfort levels.
MANUAL LIGHTING
PROCEDURE
1. Remove front panel (see Figure 7, page 8).
2. Follow steps 1 through 5 under Lighting
Instructions, page 16.
3. With thermostat control knob pressed in,
strike match. Hold match to pilot until
pilot lights.
4. Keep thermostat control knob pressed in
for 30 seconds after lighting pilot. After 30
seconds, release control knob. Follow step
8 under Lighting Instructions, page 16.
5. Replace front panel.
INSPECTING HEATER
Check pilot flame pattern and burner flame pat-
tern often.
PILOT FLAME PATTERN
Figure 25 shows a correct pilot flame pattern. Figure
26 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 26
• turn heater off (see To Turn Off Gas to Appli-
ance, page 15, depending on your model)
• 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.
Thermocouple
Pilot Burner
Pilot Burner
Thermocouple
Blue Flame
Yellow Flame
Figure 25 - Correct Pilot Flame Pattern
Figure 26 - Incorrect Pilot Flame Pattern
BURNER FLAME PATTERN
Figure 27 shows a correct burner flame pattern. Fig-
ure 28 shows an incorrect burner flame pattern.
If burner flame pattern is incorrect, as shown in
Figure 28
• turn heater off (see To Turn Off Gas to Appli-
ance, page 15, depending on your model)
• see Troubleshooting, page 19
Figure 27 - Correct Burner Flame Pattern
Figure 28 - Incorrect Burner Flame
Pattern