www.desatech.com 113101-01C22OPERATING HEATERContinuedTO TURN OFF GASTO APPLIANCEShutting Off HeaterTurn control knob clockwise to the OFFposition.Shutting Off Burners Only (pilot stays lit)Turn control knob clockwise to thePILOT position.THERMOSTAT CONTROLOPERATIONThe thermostat control knob can be set to anycomfort level between HI and LO. The ther-mostat will gradually modulate the heat outputand flame height from higher to lower settingsor pilot, in order to maintain the comfort levelyou select. The ideal comfort setting will varyby household depending upon the amount ofspace to be heated, the output of the centralheating system, etc.Note: Selecting the HI setting with the controlknob will cause the burner to remain fully on,without modulating down in most cases.MANUAL LIGHTINGPROCEDURE1. Follow steps 1 through 5 under LightingInstructions on page 21.2. Depress control knob and light pilotwith match.3. Keep control knob pressed in for 30 secondsafter lighting pilot. After 30 seconds, releasecontrol knob. Now follow step 8 underLighting Instructions, page 21.BURNER PRIMARY AIR HOLESAir is drawn into the burner through the holes inthe fitting at the entrance to the burner. These holesmay become blocked with dust or lint. Periodicallyinspect these holes for any blockage and clean asnecessary. Blocked air holes will create soot.MAIN BURNERPeriodically inspect all burner flame holes with theheater running. All slotted burner flame holes shouldbe open with yellow flame present. All round burnerflame holes should be open with a small blue flamepresent. Some burner flame holes may becomeblocked by debris or rust, with no flame present. Ifso, turn off heater and let cool. Remove blockage,blocked burner flame holes will create soot.INSPECTING BURNERSCheck pilot flame pattern and burner flame pat-terns often.PILOT FLAME PATTERNFigure 30 shows a correct pilot flame pattern.Figure 31 shows an incorrect pilot flame pat-tern. The incorrect pilot flame is not touching thethermocouple. This will cause the thermocouple tocool. When the thermocouple cools, the heater willshut down.Figure 30 - Correct Pilot Flame PatternFigure 31 - Incorrect Pilot Flame PatternPilot BurnerThermocouplePilot BurnerPropane/LP Natural GasPilot Burner Pilot BurnerThermocouplePropane/LP Natural GasIf pilot flame pattern is incorrect, as shown inFigure 31• turn heater off (see To Turn Off Gas to Appli-ance, page 20 [manually-controlled models] orpage 22 [thermostatically-controlled model])• see Troubleshooting, page 25Note: The pilot flame on natural gas units willhave a slight curve, but flame should be blue andhave no yellow or orange color.