Desa FBS-5C, FBS-3C, FB-5B installation manual Inspecting Burner, Cleaning and Maintenance

INFRARED PROPANE/LP GAS HEATER

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 tempera- ture. The temperature setting knob can be set to any comfort level between 1 and 7. 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.

MANUAL LIGHTING

PROCEDURE

1.Follow steps 1 through 5 under Light- ing Instructions, page 13.

2.With control knob pressed in, strike match. Hold match to pilot until pi- lot lights.

3.Keep control knob pressed in for 30 seconds after lighting pilot. After 30 seconds, release control knob. Follow steps 8 and 9 under Lighting Instruc- tions, page 13.

INSPECTING

BURNER

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 touch- ing the thermocouple. This will cause the thermocouple to cool. When the thermo- couple cools, the heater will shut down.

If pilot flame pattern is incorrect, as shown in Figure 25

•turn heater off (seeTo Turn Off Gas to Ap- pliance, page 12 for non-thermostat mod- els or page 13 for thermostat models)

•seeTroubleshooting, pages 15 through 17

Pilot Burner

Thermocouple

Figure 24- Correct Pilot Flame Pattern

Pilot Burner

Thermocouple

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 pilot flame pattern is incorrect, as shown in Figure 27

•turn heater off (seeTo Turn Off Gas to Ap- pliance, page 12 for non-thermostat mod- els or page 13 for thermostat models)

•seeTroubleshooting, pages 15 through 17

Figure 26 - Correct Burner Flame Pattern

Bad Burner Pattern-Plaque GRH/OV 019

Figure 27 - Incorrect Burner Flame Pattern

CLEANING AND MAINTENANCE

WARNING: Turn off heater and let cool before servicing.

CAUTION: You must keep control areas, burner, and circu- lating air passageways of heater clean. Inspect these areas of heater before each use. Have heater inspected yearly by a quali- fied service person. Heater may need more frequent cleaning due to excessive lint from carpeting, bedding material, pet hair, etc.

ODS/PILOT AND BURNER

•Use a vacuum cleaner, pressurized air, or small, soft bristled brush to clean.

CLEANING BURNER PILOT AIR INLET HOLE

We recommend that you clean the unit every 2,500hoursofoperationoreverythreemonths.

We also recommend that you keep the burner tube and pilot assembly clean and free of dust and dirt. To clean these parts we recommend using compressed air no greater than 30 PSI. Your local computer store, hardware store, or home center may carry compressed air in a can. You can use a vacuum cleaner in the blow position. If using compressed air in a can, please follow the directions on the can. If you don't follow directions on the can, you could damage the pilot assembly.

1.Shut off the unit, including the pilot. Allow the unit to cool for at least thirty minutes.

2.Inspect burner, pilot for dust and dirt.

3.Blow air through the ports/slots and holes in the burner.

Clean the pilot assembly also. A yellow tip on the pilot flame indicates dust and dirt in the pilot assembly. There is a small pilot air inlet hole about two inches from where the pilot flame comes out of the pilot assembly (see Figure 28). With the unit off, lightly blow air through the air inlet hole. You may blow through a drinking straw if compressed air is not available.

Pilot Air Inlet

Hole

Pilot Assembly

Figure 28 - Pilot Inlet Air Hole

CABINET

Air Passageways

•Use a vacuum cleaner or pressurized air to clean.

Exterior

•Use a soft cloth dampened with a mild soap and water mixture. Wipe the cabi- net to remove dust.

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