Desa VN20BT, VP30BT, VP20BT Operating Heater, Inspecting Heater, To Turn Off Gas To Appliance

Models: VN20BT VN30BT VP30BT VP20BT

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TO TURN OFF GAS

OPERATING HEATER

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8.Turn control knob counterclockwise THERMOSTAT to desired heating level. The main burner should light. Set control knob to any heat level between 1 and 5.

MANUAL LIGHTING CAUTION: Do not try to ad- just heating levels by using the equipment shutoff valve.

TO TURN OFF GAS

TO APPLIANCE

Shutting Off Heater

1.Turn control knob clockwise INSPECTING HEATER 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 PILOT FLAME PATTERN to the PILOT position.

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 1 and 5. Selecting the 5 setting will cause the burner to remain fully on without modulating down in most cases.

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 9).

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, pages 14 and 15.

5.Replace front panel.

INSPECTING HEATER

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

PILOT FLAME PATTERN

Figure 21 shows a correct pilot flame pattern. Figure 22 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 22

turn heater off (see To Turn Off Gas to Appli- ance)

see Troubleshooting, page 18

Note: The pilot flame on natural gas units will have a slight curve, but flame should be blue and

Thermocouple

Blue Flame

Pilot Burner

Figure 21 - Correct Pilot Flame Pattern

Thermocouple

Yellow Flame

Pilot Burner

Figure 22 - Incorrect Pilot Flame Pattern

BURNER 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.

107886-01J

www.desatech.com

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Desa VN20BT, VP30BT, VP20BT Operating Heater, Inspecting Heater, To Turn Off Gas To Appliance, Thermostat Control Operation