Inspecting Heater

OPERATING HEATER

Continued

TO TURN OFF GAS

TO APPLIANCE

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.

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.

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)

•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
	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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116307-01A

SF20NT specifications

Desa SF20NT is a versatile and innovative gas-fired space heater designed for efficient heating solutions in various environments, whether in residential, commercial, or industrial settings. This model is known for its high performance, energy efficiency, and advanced technology, making it a popular choice among users seeking reliability and effectiveness in their heating needs.

One of the primary features of the Desa SF20NT is its impressive heating capacity. With a heating output of around 20,000 BTUs, it can effectively warm spaces up to 1,000 square feet, making it suitable for larger areas. This capability is enhanced by the heater's superior metal construction, ensuring durability and long-lasting performance.

In terms of technology, the Desa SF20NT incorporates a direct vent system that utilizes outside air for combustion. This feature not only increases efficiency but also enhances safety, as it minimizes the risk of hazardous fumes entering the living space. The direct vent system allows for installation flexibility; the unit can be vented horizontally through a wall or vertically through a roof, catering to different building designs.

Another standout characteristic of the Desa SF20NT is its thermostat control, which allows users to maintain a consistent temperature easily. This feature contributes to energy savings by enabling the heater to operate only when necessary, thus reducing unnecessary heating costs. Additionally, the unit includes a programmable timer, allowing users to set specific heating schedules, further optimizing energy use.

Safety is also a critical aspect of the Desa SF20NT design. It comes with built-in safety features such as a flame sensor and a safety shut-off system, ensuring that the heater operates under safe conditions at all times. The unit is designed to meet stringent safety standards, giving users peace of mind.

In summary, the Desa SF20NT is a powerful, efficient, and safe space heater that is equipped with modern features and technologies. With its high heating capacity, direct vent system, thermostat control, and safety mechanisms, it stands out as an excellent choice for anyone looking for reliable heating solutions. Whether for home or business use, the Desa SF20NT is built to provide comfort and efficiency year-round.

Desa SF20NT installation manual Inspecting Heater

Models: SF20NT