A.O. Smith BTH 300A, BTH 400A warranty Sequence of Operation, Self Diagnostic Controller

Page 18

OPERATION

SEQUENCE OF OPERATION

Typical Control/Appliance Operating Sequence

1.When the control is powered, it should first display “0”, then the input line voltage (“120”), the calibration setting (12), then the actual water temperature in the tank.

2.If the control determines that the actual water temperature inside the tank is below the programmed temperature setpoint less the differential, a call for heat is activated.

3.The control then performs selected system diagnostic checks. This includes confirming the proper state of the air switches and ECO limit device.

4.If all checks are successfully passed, the combustion blower is energized for the pre-purge cycle.

5.When the pre-purge cycle is complete, power is applied to the ignitor element for the ignitor warm-up period.

6.At the conclusion of the igniter warm-up period, the gas valve will open, allowing gas to enter the burner chamber.

7.The igniter will remain on for a short predetermined time period, then will be turned off.

8.After an additional 2 seconds, the control will monitor the flame sense probe to confirm a flame is present. If a flame is not verified within this time period, the gas valve will immediately be closed, and the blower will continue to run for approximately 10 seconds. The control will then return to step 2.

9.If a flame is confirmed, the control will enter the heating mode where it will continue heating the tank water until the setpoint temperature plus differential is reached. At this point, the gas valve is closed and the control enters the post-purge cycle.

10.The combustion blower will run for the duration of the post purge cycle to purge the system of all combustion gases. When the post purge cycle is complete, the blower is de-energized and will coast to a stop.

11.The control will now enter the idle state while continuing to monitor the internal tank water temperature and the state of other system devices. If the temperature drops below the setpoint value less differential, the control will automatically return to step 2 and repeat the entire operating cycle. During this idle state, if the control detects an improper operating state for external devices such as the ECO switch, vent switch, pressure switch, etc., the appropriate LED(s) on the Display Board will be illuminated indicating the nature of the fault.

SELF DIAGNOSTIC CONTROLLER

This controller is designed for ignition lockout after three consecutive failed attempts to light. If lockout occurs, the display lights will match Figure 17. Along with this, a numeric message will appear in the display. The following list of ERROR CODES illustrates possible numeric failures.

FIGURE 17.

GAS VALVE LED FLASHING

This condition results from a failure to establish burner ignition after three successive trials. In such cases:

1.Investigate the possible cause and remedy any observations.

2.Momentarily depress the button on the display panel to reset the lockout condition.

3.Confirm proper appliance operation.

 

Possible Cause

 

Remedy

 

 

 

 

1.

Burner ground wire broken

1.

Check wire and connection

 

or corroded

 

at burner

2.

Connectors unplugged

2.

Check connections

3.

Igniter broken

3.

Replace igniter

4.

Flame probe faulty

4.

Replace flame probe

5.

Gas shut off

5.

Turn on gas supply

6.

Clogged gas valve

6.

Replace gas valve

7.

Faulty gas valve

7.

Replace gas valve

8.

Defective control

8.

Replace control

9.

Burner improperly adjusted

9.

Adjust burner

10. Dirty burner

10. Clean burner

 

 

 

 

18

Page 17 Page 19
Image 18
Page 17 Page 19
Contents Cyclone XHE Model BTH 300A and 400A ROUGH-IN-DIMENSIONS ForewordGAS Valve Piping Table of Contents FeaturesQuick Installation Tips Horizontal Sidewall Venting Vertical Rooftop VentingWater Temperature Setpoint Adjustment Procedure High Limit Switch E.C.ODishwashing Machine Requirement Required Ability Installation InstructionsCirculating Pump Insulation BlanketsUnconfined Space ClearancesHard Water Confined SpaceUS Direct Vent Canadian Direct VentUS Horizontal Vent Canadian Horizontal VentDirect Vent Terminal Installation Vent Pipe TerminationDirect Venting Installation Sequence Vertical Vent Terminal InstallationInstallation of Vent System Vent Length TableBlocked Outlet Prover Switch Controls and SwitchesBlower Prover Switch Blocked Inlet Prover SwitchHOT Surface Igniter GAS PipingConnection of GAS Pipe System Connections Heater Wiring Page Sequence of Operation Self Diagnostic ControllerOperation GAS Valve LED FlashingError Codes Fault ConditionsECO Switch OPEN. See Figure Adjustment Procedure Initial START-UP Operating InstructionsPrior to Start UP Required Ability Operating Instructions What to do if YOU Smell GASGeneral Information Draining Maintenance ScheduleFlushing Sediment RemovalPower Supply LED Meanings Powered Anode SystemPowered Anode Operation Drain Valve and Access PanelsInstallation Diagrams Install in Accordance with Local Codes Must be Identical Heaters Install in Accordance with Local Codes Page Manifold Kits Water is TOO HOT Burner Operational ProblemsNot Enough or no HOT Water Water Heater Makes SoundsMotor will not RUN Motor RUNS, Burner Lights Momentarily Then Locks OUTReplacement Parts Noisy Burner OperationGAS Fails to Shut OFF Model BTH Limited Warranty

BTH 300A, BTH 400A specifications

A.O. Smith has established itself as a leader in the water heating industry, offering a range of products that combine efficiency, reliability, and innovative technology. Among these products, the BTH 300A and BTH 400A models stand out for their advanced features and robust performance, catering to both residential and commercial needs.

The BTH 300A and BTH 400A are high-efficiency water heaters designed with cutting-edge condensing technology, allowing for significant energy savings compared to traditional water heating systems. These models utilize a modulating gas valve that adjusts the burner operation based on the demand for hot water. This smart system not only enhances efficiency but also ensures a consistent supply of hot water without the worry of fluctuations.

One of the standout features of the BTH series is its compact design. Both the BTH 300A and BTH 400A are engineered to fit into smaller spaces, making them ideal for properties with limited installation areas. Their lightweight construction and user-friendly installation features further simplify the process, ensuring that homeowners and professionals alike can set them up with ease.

The BTH models are equipped with advanced control systems that offer precise temperature adjustment capabilities. Users can easily customize their hot water settings to meet specific household or business requirements. This adaptability is supported by the built-in digital display, which provides real-time information about the operating status of the unit.

Safety is a key consideration in the design of the BTH 300A and BTH 400A. They feature a robust set of safety mechanisms, including temperature lockout and venting safeguards, ensuring reliable operation and peace of mind for users. A.O. Smith also understands the importance of longevity in water heaters, and these models are built with high-quality materials, making them resistant to corrosion and wear over time.

In terms of performance, both the BTH 300A and BTH 400A models deliver exceptional heating capabilities, capable of meeting high demands while maintaining efficiency. With customer satisfaction at the forefront, A.O. Smith backs these units with an extensive warranty, demonstrating their commitment to quality and long-term performance.

In summary, the A.O. Smith BTH 300A and BTH 400A water heaters exemplify the marriage of innovation and functionality. With their energy-efficient operation, customizable settings, compact design, and advanced safety features, these models are a compelling choice for those in need of reliable and effective hot water solutions.
Top Page Image Contents