Bradford-White Corp U4TW40TFRN, U4TW50TFRN, U4TW60TFRN service manual* Pressure Switch Testing

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Gas control power

switch

Pressure Switch Testing

Pilot Inspection, Testing and Replacement (cont’d)

Step 15. Inspect the pilot tubing and pilot orifice for blockages:

a)Remove ferrule nut from the bottom of the pilot assembly using a 7/16" wrench.

b) Remove the pilot tube and pilot orifice.

c)Inspect the pilot tubing and pilot orifice for blockages. Clean or replace, as neces- sary.

Step 16. Reassemble the pilot assembly and install it on the main burner. Reinstall the burner assembly into the combustion chamber. Re- store the gas supply and check for gas leaks.

Step 17. To resume operation, follow the instructions located on the wa- ter heater lighting instruction label. Or, use the lighting instructions located in the water heater installation and operating manual.

Pressure Switch Testing

WARNING

115 volt potential exposure. Use caution making voltage checks to avoid

personal injury.

Step 1. Move the gas control power switch to the “OFF” position.

Step 2. Remove the three screws (Phillips screw driver) from the con- trol access cover on the blower assembly and remove

cover (see photo 1).

Step 3. Carefully remove pres-

sure switch from blower housing (see photo 2).

1

2

Pressure Switch

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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