107885-01D
For more information, visit www.desatech.com
For more information, visit www.desatech.com
16
GRH/OV 008
BAD PILOT/LP
GRH/OV 007
GOOD PILOT/LP
INSPECTING HEATER
Thermocouple
Pilot
Burner
Pilot
Burner
Thermocouple
Blue
Flame
Yellow Flame
OPERATING HEATER (THERMOSTAT MODELS)
To Turn Off Gas To Appliance
Thermostat Operation
Manual Lighting Procedure
INSPECTING HEATER
Pilot Flame Pattern
Burner Flame Pattern
OPERATING HEATER
Continued
1.
Follow steps 1 through 5 under Lighting Instructions, page 15.
2.
With thermostat control knob pressed in, strike match.
Hold match to pilot until pilot lights.
3.
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 15.
Shutting Off Heater
1.
Turn thermostat control knob clockwise
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 thermostat control knob clockwise
Clockwise
to the PILOT
position.
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 tem-
perature. 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
temperature (depending on housing construction, installation
location, room size, open air temperatures, etc.) Frequent use of
your heater will let you determine your own comfort levels.
TO TURN OFF GAS
TO APPLIANCE
MANUAL LIGHTING
PROCEDURE
Check pilot flame pattern and burner flame pattern often.
PILOT FLAME PATTERN
Figure 24 shows a correct pilot flame pattern. Figure 25 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 25
• turn heater off (see To Turn Off Gas to Appliance, page 14 [non-
thermostat models] or page 16 [thermostat models])
• see Troubleshooting, pages 19 through 21
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.
Figure 24 - Correct Pilot Flame
Pattern
Figure 25 - Incorrect Pilot Flame
Pattern
BURNER FLAME PATTERN
Figure 26 shows a correct burner flame pattern. Figure 27 shows an
incorrect burner flame pattern.
If burner flame pattern is incorrect, as shown in Figure 27
• turn heater off (see To Turn Off Gas to Appliance, page 14 [non-
thermostat models] or page 16 [thermostat models]))
• see Troubleshooting, pages 19 through 21
Figure 26 - Correct Burner
Flame Pattern
Bad Burner Pattern-Plaque
GRH/OV 019
Figure 27 - Incorrect Burner
Flame Pattern
