Bradford White TTW 75 SERIES Service Manual

Save this manual for future referenceManual 47150ASERVICEMANUALFor Bradford WhiteTTW® Series Models:M2TW75T*(BN,CX)TW475S76(B,C)* (N,X)(*) Denotes War

Steady state operation.During Steady State Operation the Control Monitors:Thermostat temperature sensor- When set point temperature is satisfied, gas

Sequence of OperationAbnormal Operation (cont.)3. Pressure Switch/Blower Temperature Fault:a) Pressure switch closed at start of call for heat - The g

Short flash, once everyfour seconds“Heartbeat”, alternatesbright/dimThermostat callingfor heat (no fault).Short flash once persecondWeak pilot signalo

Six-four flash, threesecond pauseUndesired-falsepilot flamesensed.System autoresets.Seven flash, threesecond pauseSimulatedResistive DeviceHarness out

Step 1. With main burner in operation, remove outer jacket door and slide inner door from left to right to open.Step 2. To adjust for proper burning,

Burner CleaningStep 1. Position gas control power switch to the“OFF” position and unplug heater from walloutlet.Step 2. Turn off gas supply to water h

TTW SERVICE PROCEDURE IIPilot testing, Cleaning and ReplacementPilot Inspection, Testing and ReplacementStep 1. Position gas control power switch to

TTW SERVICE PROCEDURE IIIPressure Switch Testing andReplacementPressure Switch TestingWARNING120 volt potential exposure. Use cautionmaking voltage ch

Pressure Switch ReplacementWARNING120 volt potential exposure. Use cautionto avoid personal injury.Step 6. Reconnect wires from step 5 to new pressure

TTW SERVICE PROCEDURE IVBlower Testing and ReplacementWARNING115 volt potential exposure. Use caution whenmaking voltage checks to avoid personal inj

Bradford WhiteTTW SeriesGas Water HeatersTable of ContentsPage TTW Service ProcedureIntroduction 4 - - -How to use this manual 5 - - -Tool required

TTW SERVICE PROCEDURE IVBlower Testing and ReplacementStep 1. Position gas control power switch to the “OFF” position.Step 2. Unplug blower power cor

TTW SERVICE PROCEDURE VBlower Temperature Switch Testingand ReplacementBlower Temperature SwitchTesting.WARNING120 volt potential exposure. Use cauti

TTW SERVICE PROCEDURE VBlower Temperature Switch Testingand ReplacementBlower Temperature SwitchReplacement.WARNING120 volt potential exposure. Use c

Thermal Well TestingPosition gas valve powerswitch to the “OFF”position and disconnectthermal well harness fromgas control.NYUsing a multi-meter set t

°F012345678 940 26109 25400 24712 24045 23399 22771 22163 21573 21000 2044550 19906 19383 18876 18383 17905 17440 16990 16553 16128 1571560 15314 1492

TTW SERVICE PROCEDURE VIGas Control & Thermal Well Testingand ReplacementGas Control & Thermal Well Removal From Water HeaterStep 1. Position

Gas Control Assembly to Thermal WellStep 6. Reconnect wire harnesses to gas controlper the illustration.Step 7. Reconnect gas piping to gas control.Re

TTW SERVICE PROCEDURE VIISimulated Resistive Device TestingSimulated ResistivedeviceStep 1. Position power switch on gas control to the“OFF” position

TTW SERVICE PROCEDURE VIIISafety Circuit Voltage TraceSafety Circuit VoltageTraceWARNING120 volt potential exposure. Use cautionmaking voltage checks

TTW SERVICE PROCEDURE IX120 VAC TraceWARNING120 volt potential exposure. Use cautionmaking voltage checks to avoid personal injury.Disconnect cord set

WARNING: If the information in theseinstructions is not followed exactly, a fire orexplosion may result causing property damage,personal injury, or d

TTW SERVICE PROCEDURE XDip TubeInspection and replacementStep 1. Position on/off switch of gas control valve to “OFF” position and unplug water heate

TTW SERVICE PROCEDURE XIAnodeInspection and replacementStep 1. Position on/off switch of gas control valve to the “OFF” position and unplug water heat

TTW SERVICE PROCEDURE XIIFlue BaffleInspection and replacementStep 1. Position gas control power switch to the “OFF” positionand unplug blower from wa

NOTESPage 33Glossary of TermsBTU British Thermal UnitsGPM Gallons per MinuteHz HertzKW/h Kilowatts per hourLED Light Emitting DiodeNPT National Pipe T

NOTESPage 3434

Parts List1. Blower Complete2. Air Mixing Inlet cover3. Pressure Switch4. Blower Temp. Switch5. Blower Gasket6. Blower Power Cord7. Vent Adapter8. Con

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Page 4IntroductionThe new Bradford White TTW2 & TW4 water heaters are designed to provide reliableperformance with enhanced standard features. Ne

Tools Required for ServiceIt is intended for this manual to be used by qualified service personal for the primary purpose oftroubleshooting and repair

SpecificationsThermal well TCO Limit Residential 188°F (87°C), Commercial 199°F (93°C)Residential TemperatureSet Point Range60°F (16°C) to 160°F (71°C

SpecificationsVenting Specifications:Through the WallTerminating# ofElbowsMaximumLength ft (m)MinimumLength ft (m)3" Diameter (7.6 cm) PVC Vent C

Control TimingsIgnition StateTimingPre-purge2 SecondsTrial for Ignition 90 SecondsFlame Stabilization Period 3 SecondsInter-purge 15 SecondsFlame Fail

Sequence of OperationThermostat calls for heat.Prior to energizing blower, gas control checks safety circuit to insure the circuit is open. Normal swi