Carrier 48TCA04---A12 Service And Maintenance Instructions

24This switch also prevents operation when the propane tanklevel is low which can result in gas with a highconcentration of impurities, additives, and residues thathave settled to the bottom of the tank. Operation underthese conditions can cause harm to the heat exchangersystem. Contact your fuel supplier if this condition issuspected.Flue Gas PassagewaysTo inspect the flue collector box and upper areas of theheat exchanger:1. Remove the combustion blower wheel and motor as-sembly according to directions in Combustion--AirBlower section. See Fig. 31.2. Remove the flue cover to inspect the heat exchanger.3. Clean all surfaces as required using a wire brush.Combustion--Air BlowerClean periodically to assure proper airflow and heatingefficiency. Inspect blower wheel every fall andperiodically during heating season. For the first heatingseason, inspect blower wheel bi--monthly to determineproper cleaning frequency.To access burner section, slide the sliding burner partitionout of the unit.To inspect blower wheel, shine a flashlight into draft hoodopening. If cleaning is required, remove motor and wheelas follows:1. Slide burner access panel out.2. Remove the 7 screws that attach induced--draft motorhousing to vestibule plate. (See Fig. 31.)3. The blower wheel can be cleaned at this point. If ad-ditional cleaning is required, continue with Steps 4and 5.4. To remove blower from the motor shaft, remove 2setscrews.5. To remove motor, remove the 4 screws that hold themotor to mounting plate. Remove the motor coolingfan by removing one setscrew. Then remove nuts thathold motor to mounting plate.6. To reinstall, reverse the procedure outlined above.Flue Baffle(Low NOx only)Heater TubeAssemblySeal Strips, Sponge RubberRegulatorGasketRegulatorBaffle Assembly(Low NOx only)RetainerSupportInsulationAssemblyWind Cap Assembly(shown inverted,as shipped)Burner AssemblyInducer Fan-MotorAssemblyC08227Fig. 31 -- Heat Exchanger Assembly48TC