Bradford-White Corp U4TW40TFRN, U4TW50TFRN ScreenLok Flame Arrestor Cleaning Procedure

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Arrestor Cleaning

screws. Verify that both the left and right side inner doors are properly positioned and sealed against the combustion chamber.

Step 8. Re-install the outer door.

Step 9. To resume operation, follow the instructions located on the water heater lighting instruction label. Or, use the lighting instructions located in the water heater installation and operating manual.

ScreenLok® Flame Arrestor Cleaning Procedure

Step 1. Move the gas control power switch to the “OFF” position and unplug the water heater from the wall outlet.

Step 2. Remove the outer door.

Step 3. Remove the right side inner door per the Inner Door Removal Procedure on page 32.

Step 4. Disconnect the pilot tube using a 7/16” wrench and the main burner feedline with a 3/4” wrench from the gas control.

Step 5. Disconnect the spark igniter/flame sensor wire from gas control.

Step 6. Remove the burner assembly from the combustion chamber.

Step 7. Clean the ScreenLok® flame arrestor using a stiff brush, compressed air, and/or a shop vacuum to remove any scale or other debris accumulation. Using a soft brush, clear jacket openings from any dirt, dust, restrictions, or other obstructions.

Step 8. Remove any debris from the burner assembly following the Burner Cleaning Procedure on page 15.

Step 9. Re-install the burner assembly.

Step 10. Reconnect the main and pilot tubing and spark igniter wire to the gas control.

Step 11. Re-install the inner door per the Inner Door Installation with Gasket Pro- cedure on page 34.

Step 12. To resume operation, follow the instructions located on the water heater lighting instruction label. Or, use the lighting instructions located in the water heater installation and operating manual.

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Contents Service Manual Table of Contents Page Page Introduction Bradford White ECO-DEFENDER Safety SystemHow the Safety System Works How to Use this ManualTools Required Tools Required for ServiceSpecifications Gallon Vent TablesSpecifications Control Timings Wiring DiagramSequence of Operation Power Up SequenceNormal Heating Sequence Abnormal Operation Normal Heating Sequence cont’dAbnormal Operation cont’d Sequence of Operation Sequence of Operation LED Status Control Status Probable Cause Service Procedure TroubleshootingTroubleshooting Troubleshooting Burner Cleaning Procedure Burner MaintenanceBurner Inspection Burner Cleaning Procedure cont’d Pilot Inspection, Testing and Replacement Pilot MaintenancePilot Inspection, Testing and Replacement cont’d Page Pressure Switch Testing Pressure Switch TestingPressure Switch Testing cont’d Pressure Switch Replacement Pressure Switch ReplacementBlower Testing Blower TestingPage Blower Installation Blower ReplacementBlower Removal Blower Installation cont’d Blower Temperature Switch TestingBlower Temperature Switch Testing Switch Setting Blower Temperature Switch Testing cont’dBlower Temperature Switch Replacement Blower Temperature Switch ReplacementThermal Well Testing Thermal Well TestingThermal Well Testing cont’d Determine Tank TemperatureDetermine Water Temperature Inside Tank Sensor Resistance at Various Temperatures Component DisassemblyGas Control & Thermal Well Removal From Water Heater Gas Control Removal Gas Control Assembly to the Thermal Well Gas Control AssemblyGas Control Removal From Thermal Well cont’d Gas Control Assembly to the Thermal Well cont’d Flammable Vapor Sensor Testing Flammable Vapor Sensor TestingVAC Circuit Trace Safety Circuit Voltage Trace Safety Circuit Voltage TraceBlower Removal Remove the Blower to Gain Access to the Flue BaffleDip Tube Inspection and Replacement Remove the Blower to Gain Access to the Flue Baffle cont’dDip Tube Inspection Anode Inspection Anode Inspection and ReplacementInner Door Removal Inner Door Removal ProcedureInner Door Removal Procedure cont’d Inner Door Gasket ReplacementInner Door Gasket Replacement Procedure Inner Door Installation with Gasket Inner Door InstallationScreenLok Flame Arrestor Cleaning Procedure Arrestor CleaningCommon Terms Common TermsPart Name and Description Parts ListParts@bradfordwhite.com Techserv@bradfordwhite.com