Bradford-White Corp D4504S*F(BN Sequence of Operation, Power Up Sequence, Normal Heating Sequence

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Sequence of Operation

Power Up Sequence

1.Start-up:Upon power up, the gas control runs a safe start check with a typical de- lay of 5 seconds.

2.Flammable Vapor Verification: The gas control verifies that the Flammable Vapor Sensor is in the proper operating range prior to energizing any components. If the sensor is within the proper range, the gas control resumes normal operation. If the Flammable Vapor Sensor is out of range, the gas control LED immediately flashes 7 times with a 3 second pause.

Normal Heating Sequence

When the phrase “Damper Open” is used, this means that the damper blade is in the vertical position (open). Alternatively, “Damper Closed” means that the damper blade is in the horizontal position (closed). This must not be confused with the phrase “Damper Circuit Open,” as this means that the damper blade is in the horizontal posi- tion. “Damper Circuit Closed” means that the damper blade is in the vertical position, and the water heater can proceed to an ignition trial.

1.Thermostat Calls for Heat: Prior to energizing the damper, the gas control verifies the damper safety circuit to see if it is in the correct state. If the safety circuit is closed, the gas control LED flashes 2 times with a 3 second pause. The gas con- trol waits 2 minutes. Then, the damper is powered closed. This cycle repeats until the safety circuit opens.

2.Damper Powered Open

3.Damper Safety Circuit Check: If the damper safety circuit does not close within 30 seconds, the gas control LED flashes 3 times with a 3 second pause. The damper is powered open for a maximum of 30 seconds every 2 minutes trying to close the damper safety circuit. This cycle repeats as long as there is a call for heat.

4.Damper Hold Period (15 seconds)

5.Trial for Pilot Ignition (90 seconds): The gas control lights the pilot by activating the spark igniter and gas flow to the pilot burner. If flame is not sensed within 90 seconds, the spark igniter and gas flow are deactivated. The damper will remain open, and the gas control LED flashes 6 times with a 3 second pause.

6.Main Burner Ignition: After pilot flame is sensed, the gas control activates the main valve for main burner ignition. The gas control will ignore flame signals for 3 seconds to allow for the main burner to stabilize.

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Contents Service Manual Table of Contents Page Page How the Safety System Works Bradford White Defender Safety SystemIntroduction IntroductionHow to Use this Manual How to Use this ManualSpecifications Wiring Diagram Damper Powered Open Power Up SequenceSequence of Operation Normal Heating SequenceNormal Heating Sequence cont’d Abnormal Operation cont’d Temperature Sensor Fault Damper Safety Circuit FaultTrial for Ignition Fault Abnormal Operation cont’d Flame Sensing Fault Probable Cause Service Procedure TroubleshootingLED Status Control Status Probable Cause Service Procedure Burner Maintenance Burner Cleaning ProcedureBurner Inspection Right side inner door Main burner Orifice Pilot Maintenance Burner Cleaning Procedure cont’dPilot Inspection, Testing and Replacement Pilot Inspection, Testing and Replacement cont’d Damper Removal & Installation Damper ReplacementDamper Removal & Installation cont’d Thermal Well Testing Thermal Well TestingDetermine Tank Temperature Thermal Well Testing cont’dDetermine Water Temperature Inside Tank Component Disassembly Sensor Resistance at Various TemperaturesGas Control & Thermal Well Removal From Water Heater Gas Control Removal Gas Control & Thermal Well Removal From Water Heater cont’dGas Control Removal From Thermal Well Gas Control Assembly Gas Control Assembly to the Thermal WellGas 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 Dip Tube Inspection Dip Tube Inspection and ReplacementAnode Inspection Anode Inspection and ReplacementDamper Removal Remove the Damper to Gain Access to the Flue BaffleRemove the Damper to Gain Access to the Flue Baffle cont’d Inner Door Removal Inner Door Removal ProcedureInner Door Gasket Replacement Inner Door Removal Procedure cont’dInner Door Gasket Replacement Procedure Inner Door Installation with Gasket Inner Door InstallationArrestor Cleaning ScreenLok Flame Arrestor Cleaning ProcedureDamper Relay Installation Damper Relay Installation cont’d Damper Relay InstallationConnect the other ends of the relay harness, as shown Common Terms Common TermsPart Name and Description Parts ListParts@bradfordwhite.com Techserv@bradfordwhite.com

SX), D4504S*F(BN, D4403S*F(BN specifications

Bradford-White Corp has long been a pioneering name in the water heating industry, and their D4403S*F(BN, D4504S*F(BN, and SX models represent the company’s commitment to delivering high-quality, efficient solutions for residential and commercial applications. These water heaters are designed with various user needs in mind, ensuring that homeowners and businesses can enjoy a reliable hot water supply whenever needed.

One of the core features of these models is their advanced water heating technology. Utilizing power venting systems, these units ensure efficient heat transfer while minimizing heat loss. This technology promotes energy efficiency and helps users save on their energy bills. The power vent system also allows for flexible installation options, accommodating different types of venting configurations, which is especially useful in homes with unique designs or limited space.

The Bradford-White D4403S*F(BN and D4504S*F(BN models are equipped with their state-of-the-art Hydrojet Total Performance System. This feature not only enhances the heater's overall performance but also reduces sediment buildup within the tank, which can significantly extend the unit's lifespan and maintain efficiency over time. Moreover, the patented Vitraglas® lining protects the inner tank from corrosion, further prolonging the life of the appliance.

Safety is a paramount consideration in Bradford-White's design philosophy. Each model includes a robust Flammable Vapor Ignition Resistance (FVIR) system, which helps prevent the ignition of flammable vapors that may be present in the vicinity of the water heater. This feature meets stringent safety standards and provides peace of mind to users.

In terms of energy specifications, both the D4403S*F(BN and D4504S*F(BN models are designed to meet or exceed efficiency standards, contributing to lower energy consumption and environmental impact. The SX model is particularly notable for its user-friendly digital display and controls, allowing for easy temperature adjustments and efficient operation monitoring.

In conclusion, Bradford-White Corp's D4403S*F(BN, D4504S*F(BN, and SX models are a testament to the company’s dedication to quality, safety, and efficiency in water heating technology. With their innovative features, user-friendly design, and long-lasting durability, these water heaters are well-suited to meet the ever-evolving demands of modern households and commercial settings alike. As homeowners and businesses continue seeking reliable hot water solutions, Bradford-White stands out as a trusted choice in the industry.
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