Desa Tech CGN20TA Inspecting Burner, Thermostat Control Operation, Pilot Flame Pattern

Page 13

OWNER’S MANUAL

OPERATING

HEATER

Continued

THERMOSTAT CONTROL

OPERATION

The thermostatic control used on these models differs from standard thermo- stats. Standard thermostats simply turn on and off the burner. The thermostat used on this heater senses the room tem- perature. 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.

Note: The thermostat sensing bulb mea- sures the temperature of air near the heater cabinet. This may not always agree with room temperature (depending on housing construction, installation loca- tion, room size, open air temperatures, etc.). Frequent use of your heater will let you determine your own comfort levels.

INSPECTING

BURNER

Check pilot flame pattern and burner flame pattern often.

PILOT FLAME PATTERN

Figure 18 shows a correct pilot flame pat- tern. Figure 19 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.

Pilot Burner

Thermocouple

Figure 18 - Correct Pilot Flame Pattern

BURNER FLAME PATTERN

Figure 20 shows a correct burner flame pattern. Figure 21 shows an incorrect burner flame pattern. The incorrect burner flame pattern shows yellow tipping of the flame. It also shows the flame higher than 1/2 the glass panel height.

WARNING: If yellow tipping occurs, your heater could pro- duce increased levels of carbon monoxide. If burner flame pat- tern shows yellow tipping, follow instructions at bottom of this page.

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.

1/2

1/2 G Glass

Height

Correct Flame Pattern

At High Position

MANUAL LIGHTING

PROCEDURE

1.

Remove front panel (see Figure 7,

 

page 8).

2.

Follow steps 1 through 5 under Light-

 

ing Instructions, page 12.

3.

With control knob pressed in, strike

 

match. Hold match to pilot until pi-

Thermocouple

Pilot Burner

Figure 20 - Correct Burner Flame Pattern

Yellow Tipping

1/2

Glass

Height

Incorrect Flame Pattern

 

lot lights.

4.

Keep control knob pressed in for 30

 

seconds after lighting pilot. After 30

 

seconds, release control knob.

5.

Replace front panel.

Figure 19 - Incorrect Pilot Flame Pattern

If pilot flame pattern is incorrect, as shown in Figure 19.

turn heater off (see To Turn Off Gas to Appliance, page 12).

see Troubleshooting, pages 14 through 16.

At High Position

Figure 21 - Incorrect Burner Flame Pattern

If burner flame pattern is incorrect, as shown in Figure 21

turn heater off (see To Turn Off Gas to Appliance, page 12)

see Troubleshooting, pages 14 through 16

104190

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Contents What to do if YOU Smell GAS Blue Flame VENT-FREE Natural GAS HeaterCGN20TA Safety InformationProduct Identification Product FeaturesLocal Codes UnpackingProviding Adequate Ventilation Fresh AIR for Combustion and VentilationUnusually Tight Construction Confined and Unconfined SpaceDetermining if You Have a Confined or Unconfined Space Determining FRESH-AIR Flow for Heater LocationVentilation Air From Inside Building Ventilation AIRVentilation Air From Outdoors Installation Items InstallationCheck GAS Type Locating HeaterThermostat Sensing Bulb Installing Heater to WallAttaching Mounting Bracket To Wall Installing Bottom Mounting ScrewsPlacing Heater On Mounting Bracket Typical Inlet Pipe Diameters Connecting to GAS SupplyPressure Testing Heater GAS Connections Pressure Testing GAS Supply Piping SystemChecking GAS Connections Test Pressures In Excess Of 1/2Operating Heater For Your Safety Read Before LightingLighting Instructions To Turn OFF GAS To ApplianceInspecting Burner Manual Lighting ProcedureThermostat Control Operation Pilot Flame PatternObserved Problem Possible Cause Remedy TroubleshootingMaintenance, Gas leak. See Warning statement at Service Publications Replacement Parts Cleaning and Maintenance SpecificationsTechnical Service Service HintsFBD Parts CentralsFAN Kits GA3100A and GA3200TA AccessoriesManual Shutoff CGN20TA Illustrated Parts BreakdownKEY Part Number Description QTY Parts ListCGN20TA 104190 Warranty Information