Desa GWP20T GWN30T - Manual (Page 15)

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15
15
IGNITOR
PILOT LO
OFF
HI
INSPECTING HEATER
Check pilot flame pattern and burner flame pattern often.
PILOT FLAME PATTERN
Figure 23 shows a correct pilot flame pattern. Figure 24 shows an
incorrect pilot flame pattern. The incorrect 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 24
• turn heater off (see To Turn Off Gas to Appliance, page 14 or 15)
• see Troubleshooting, pages 17 through 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.
CAUTION: Do not try to adjust heating levels by
using the equipment shutoff valve.
Figure 21 - Control Knob In The OFF Position
Shutting Off Heater
1. Turn control knob clockwise to the OFF position.
2. Turn off all electric power to the appliance if service is to
be performed.
Shutting Off Burner Only (pilot stays lit)
Turn control knob clockwise to the PILOT position.
Figure 22 - Pilot (actual pilot may vary)
Ignitor Button Control Knob
TO TURN OFF GAS TO APPLIANCE
THERMOSTAT CONTROL 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. The thermostat adjusts the amount of
gas flow to the burner. This increases or decreases the burner
flame height. 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 heat level between HI and LO.
Selecting the HI setting will cause the burner to remain fully on
without modulating down in most cases.
OPERATING HEATER
Continued
OPERATING HEATER (THERMOSTAT CONTROLLED MODELS)
Lighting Instructions (Cont.)
Thermostat Control Operation
Manual Lighting Procedure
INSPECTING HEATER
Pilot Flame Pattern
Note: The thermostat sensing bulb measures the temperature
of air near the heater cabinet. This may not always agree with
room temperature (depending on housing construction, instal-
lation location, room size, open air temperatures, etc.). Fre-
quent use of your heater will let you determine your own
comfort levels.
1. Remove front panel (see Figure 7, page 8).
2. Follow steps 1 through 5 under Lighting Instructions, page 14.
3. With control knob pressed in, strike match. Hold match to
pilot until pilot lights.
4. 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 14.
5. Replace front panel.
MANUAL LIGHTING PROCEDURE
Figure 24 - Incorrect Pilot Flame
Pattern Figure 23 - Correct Pilot
Flame Pattern
Thermocouple
Pilot Burner
Pilot
Burner
Thermocouple
Blue Flame
Yellow Flame
Ignitor Electrode
Pilot Burner
Thermocouple