OPERATING HEATER

Continued

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. 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 1 and 5. This adjusts the amount of gas flow to the burner that increases or decreases the burner flame height. 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 10, page 9).

2.Follow steps 1 through 7 under Lighting Instructions, page 13.

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 9, under Lighting Instructions, page 13.

5.Replace front panel.

INSPECTING HEATER

Check pilot flame pattern and burner flame pat- tern often.

PILOT FLAME PATTERN

Figure 18 shows a correct pilot flame pattern. Figure 19 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 19

turn heater off (see To Turn Off Gas to Ap- pliance, page 13)

see Troubleshooting, page 16

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

Blue Pilot Flame

 

 

Pilot Burner

Figure 18 - Correct Pilot Flame Pattern

Thermocouple

Yellow Pilot Flame

Pilot Burner

Figure 19 - Incorrect Pilot Flame Pattern

BURNER FLAME PATTERN

WARNING: If yellow tipping occurs, your heater could pro- duce increased levels of carbon monoxide.

NOTICE: Do not mistake orange flames with yellow tipping. Dirt or other fine particles enter the heater and burn causing brief patches of orange flame.

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Desa VSFG20PT, SPC20PT Inspecting Heater, Thermostat Control Operation, Manual Lighting Procedure, Pilot Flame Pattern