Bradford-White Corp U1TW50S*FRN, UTW450S60FR*N Normal Heating Sequence cont’d, Abnormal Operation

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Sequence of Operation

Normal Heating Sequence (cont’d)

7.Main Burner Ignition: After pilot flame is sensed, the gas control acti- vates the main valve for main burner ignition. The gas control will ig- nore flame and pressure switch signals for 3 seconds to allow for the main burner to stabilize.

8.Steady State Operation: During steady state operation, the gas control monitors:

Thermostat Temperature Sensor: When the setpoint temperature is sat- isfied, the gas control is shutdown, and the blower will post-purge for 15 seconds. The gas control LED flashes a short flash once every 4 seconds (Idle status code).

Pressure switch/blower temperature switch: If either switch opens, the pilot valve and the main valve are shut down. The blower continues to run for 30 seconds attempting to close the circuit. The gas control LED flashes 3 times with 3 second pause.

Flame Sensor: If flame is lost, the pilot and main valves are shutdown. The blower runs for 15 seconds. The gas control attempts to re-light the pilot 4 times. If unsuccessful, the blower is shutdown, and the gas con- trol proceeds to a 5 minute lockout. The gas control re-attempts to light the pilot starting at Normal Heating Sequence #2.

9.Thermostat Satisfies: Gas control LED flashes once every 4 seconds. 10.Burner Off.

11.Blower post-purge (15 seconds).

Abnormal Operation

1.Flammable Vapor Sensor Fault:

A)If the resistance is greater than 70,000 ohms: The gas control imme- diately turns off all outputs. The gas control waits and monitors resis- tance for 30 seconds. If the resistance is greater than 65,000 ohms af- ter 30 seconds, the gas control proceeds to verify resistive delay for 2 minutes and flashes 7 times then 1 time with a three second pause. This process is repeated 5 times until the control either returns to normal op- eration or proceeds to flammable vapor lockout.

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Contents Service Manual Table of Contents Page Page Introduction Bradford White ECO-DEFENDER Safety SystemIntroduction How the Safety System Works How to Use this ManualHow to Use this Manual Tools Required Tools Required for ServiceSpecifications Gallon-40,000 BTU/hr Gallon-42,000 BTU/hr Vent TablesGallon-60,000 BTU/hr Control Timings Wiring DiagramIgnition State Timing Sequence of Operation Power Up SequenceNormal Heating Sequence Abnormal Operation Normal Heating Sequence cont’dAbnormal Operation cont’d Sequence of Operation Sequence of Operation Probable Cause Service Procedure TroubleshootingLED Status Control Status Probable Cause Service Procedure 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 TestingBlower Testing Blower Installation Blower ReplacementBlower Removal Blower Installation cont’d Blower Temperature Switch TestingBlower Temperature Switch Testing Switch Setting Blower Temperature Switch Testing cont’dCommon causes for high Exhaust temperature Blower 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 & Thermal Well Removal From Water Heater cont’d Gas Control RemovalGas Control Removal From Thermal Well 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 VAC 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

U1TW40S*FRN, U2TW65T*FRN, UTW450S60FR*N, U1TW60T*FRN, UTW465S60FR*N specifications

Bradford-White Corp has long been a reputable manufacturer in the water heating industry, known for delivering high-quality and reliable products. Among their diverse range of water heaters, the U1TW40S*FRN, U1TW50S*FRN, U1TW60T*FRN, UTW465S60FR*N, and UTW450S60FR*N models stand out for their advanced features and technologies designed to meet varying hot water demands.

The U1TW series, including the U1TW40S*FRN, U1TW50S*FRN, and U1TW60T*FRN models, are well-suited for residential applications. Each model provides different capacities, with the numbers referring to the gallon capacities. The U1TW40S*FRN offers 40 gallons, the U1TW50S*FRN 50 gallons, and the U1TW60T*FRN 60 gallons, making them ideal for households varying in size and hot water requirements.

These models are equipped with Bradford-White's advanced Vitraglas® tank lining, a unique feature that provides superior protection against corrosion and extends the unit's lifespan by ensuring the inner tank remains free from damage. Additionally, their efficient heating elements and optimal insulation minimize heat loss, enhancing energy savings.

The UTW series, specifically the UTW465S60FR*N and UTW450S60FR*N, feature innovative technologies such as a durable stainless steel construction that offers robust performance while resisting the harmful effects of rust and degradation. This is particularly beneficial in areas with hard water, where mineral buildup can be problematic.

Each unit incorporates Bradford-White's signature HydroBurner® technology, which enhances combustion efficiency, ensuring that the water is heated quickly and consistently. This technology also helps in reducing greenhouse gas emissions, addressing environmental concerns while maintaining optimal performance.

In terms of ease of use, all models come with user-friendly controls that allow for easy temperature adjustments and monitoring, ensuring that users can customize their hot water needs conveniently. Additionally, features such as intuitive diagnostics enable quick troubleshooting, reducing downtime and maintenance efforts.

In conclusion, Bradford-White’s U1TW and UTW series water heaters are engineered to offer efficiency, durability, and user-friendly operation. With their advanced technology, excellent insulation, and robust construction, these models are a solid choice for anyone looking to invest in reliable hot water solutions for their home. Whether for a busy family or more modest hot water needs, these units provide peace of mind and consistent performance.
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