Ultra Low NOx Residential D Series Gas Water Heater Heaters SERVICE MANUAL Troubleshooting Guide and Instructions for Service (To be performed ONLY by qualified service providers) Models Covered by This Manual: URG1D30T*N URG1D40S*N URG1D40T*N URG1D50T*N URG2D40S*N URG2D50S*N (*) Denotes Warranty Years Manual 238‐51673‐00D 6/21 Save this manual for future reference
The Bradford White Ultra Low NOx Residential D Series Gas Water Heaters Table of Contents D Service Procedure Introduction............................................................................................................................................................. 4 --- How to Use This Manual ..................................................................................................................................... 5 --- Tools Required for Service .............................
ULN Res. D Series WARNING: If the information in these instructions is not followed exactly, a fire or explosion may result causing property damage, personal injury, or death. WHAT TO DO IF YOU SMELL GAS! • Do not try to light any appliance. • Do not touch any electrical switch; do not use any phone in your building. • Immediately call your gas supplier from a neighbor's phone. Follow the gas supplier's instructions. • If you cannot reach your gas supplier, call the fire department.
The Bradford White Introduction The new Bradford White Ultra Low NOx Residential Flue Damper water heaters are designed to provide reliable performance with enhanced standard features. New design features include reliable spark-to-pilot ignition system, enhanced diagnostics, simplified servicing, significantly quiet operation, and the Bradford White Defender Safety System.
ULN Res. D Series It is intended for this manual to be used by a qualified service personnel for the primary purpose of the troubleshooting and repairing of the Bradford White “D” Series water heaters. Understanding the sequence of operation section of this manual will contribute greatly to troubleshooting the water heater. The ICON System WV4472 electronic gas control will display status codes in the event of abnormal operation.
ULN Res. D Series Power supply Gas Supply Pipe Approved Gas Type Gas Pressure Venting System Minimum Clearance for Servicing Water Supply Pressure Gas Control ECO Limit Temperature Setpoint Range 6 6 Dedicated 115 VAC, 60 Hz, 15A Minimum 1/2” NPT (schedule 40 black iron pipe recommended) Natural Gas unit must match gas type supplied 6.0” w.c. min., 14.0” w.c. maximum Single or Double Wall Metal Vent Pipe 18” from top, 24” from front, 4” sides and rear 150 PSI maximum allowable working pressure.
ULN Res. D Series Control Timings Ignition State Adjust Damper Position and Verify (Open Position) Trial for Ignition Flame Stabilization Period Re-adjust Damper Position and Verify Flame Failure Response Time Adjust Damper Position and Verify (Closed Position) Damper Blade Position Fault (failed open/close) Soft Lockout ECO Limit Lockout Verify Resistive Delay Simulated Resistive Load Lockout Hardware Status Lockout Timing 15 Seconds 90 Seconds 3 Seconds 15 Seconds 1.
ULN Res. D Series Power Up Sequence 1. Start Up. Upon power up, the control runs a safe-start check with a typical start-up delay of 5 seconds. 2. Flammable Vapor. 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.
ULN Res. D Series Normal Heating Sequence (cont.) 7. Steady state operation. During steady state operation, the control monitors: Thermostat Temperature Sensor-when setpoint temperature is satisfied, gas valve is shut down and damper is powered closed. The gas control LED flashes a short flash once every 4 seconds (idle) status code. Damper Position-if the damper position is altered during a call for heat, the pilot and main valves are shutdown.
ULN Res. D Series Abnormal Operation (cont.) b. Thermal Well Sensor Not Reading the Same Temperature Within ±5.5°F –The gas control immediately turns off all outputs and proceeds to flash 8 times, then 3 times twice with 3 second pauses. The status self clears if the fault clears for at least 15 seconds. c. Water Temperature in Excess of ECO (Energy Cut Out) Limit -The gas control immediately turns off pilot & main valves and proceeds to flash 4 times with a 3 second pause.
ULN Res. D Series Observe green LED indicator on electronic gas control. Status flash codes are displayed with a three second pause before repeating. Check and repair the system as noted in the troubleshooting table below. LED Status None, control LED not on or flashing One short flash, once every two seconds “Heartbeat” alternates bright/dim Control Status No electrical power Stand-by mode, Waiting for call for heat (no fault). Thermostat calling for heat (no fault).
ULN Res. D Series LED Status Six-one flash, three second pause Failed to light pilot. System auto resets. Six-two flash, three second pause Damper test circuit not working properly during burner operation, system auto resets after (5) minutes. Six-three flash, three second pause Pilot flame extinguished. System auto resets. Six-four flash, three second pause Undesired-false pilot flame sensed. System auto resets.
ULN Res. D Series LED Status Nine-One flash, three second pause Nine-two flash, three second pause Control Status Insufficient combustion air detected. Chamber temperature sensor out of specification Probable Cause Insufficient combustion air 1. Chamber sensor out of calibration. 2. Possible short. Service Procedure Page 37.
ULN Res. D Series Burner Inspection At periodic intervals (every 6 months) a visual inspection should be made of the pilot and main burner for proper operation and to assure no debris is accumulating. Pilot flame should be stable, some causes for an unstable pilot flame are: a) Water heater vent is less than the allowable vent length. b) Gas pressure is out of specification. c) Pilot flame not fully engulfing spark/flame sensor.
ULN Res. D Series Burner Cleaning Step 1. Position the gas control power switch to the “OFF” position and unplug the heater from the wall outlet. Step 2. Turn off gas supply to the water heater. Remove outer jacket door. Disconnect pilot tube (7/16” wrench) and feedline (¾” wrench) from gas control. Disconnect igniter/flame sensor wire, damper wire harness and FV wire harness from the gas control. Remove the (4) ¼” hex drive screws holding the right side inner door in place. Step 3. Step 4. Step 5.
ULN Res. D Series Burner Cleaning (cont.) Step 9. Remove manifold mount from burner inner door by removing (2) ¼” hex drive screws. Step 10. Use a stiff brush, compressed air and/or a vacuum to remove any debris build up from the manifold mount. Step 11. Thoroughly inspect burner surface area and burner port area and remove any loose debris using compressed air and/or a vacuum. Step 12. Thoroughly inspect burner screen and burner venturi and remove any loose debris accumulation.
ULN Res. D Series Pilot Testing and Replacement Step 1. Visually inspect igniter/flame sense electrode for oxidation build up. Carefully clean any oxidation using very fine emery cloth. Step 2. Remove pilot assembly from the burner assembly (¼” nut driver). Step 3. Visually inspect igniter/flame sense wire for damage. Replace pilot if damage is found. Step 4. With a multi-meter set to ohms setting, check continuity through igniter/flame sense wire. Replace pilot if no continuity. Step 5.
ULN Res. D Series Damper Removal & Installation Step 1. Step 2. Step 3. Position the power switch on the gas control to the “OFF” position and unplug the water heater from the wall outlet. Disconnect the vent system from the draft hood that is mounted on top of the damper Remove the draft hood from the damper and retain it for use on the new damper. Step 4. Disconnect the cord sets from the damper. Step 5. Remove the two mounting screws from the damper using a ¼” nut driver and retain for later.
ULN Res. D Series Line Pressure The gas control is designed for a maximum line pressure of 14.0” W.C. and a minimum line pressure of 1.0” W.C. over the water heater’s rated manifold pressure (check rating plate). Line pressure must be checked with the main burner on and off to assure proper readings. Manifold Pressure Testing (this procedure presumes a maximum line pressure of 14.0” W.C.) Step 1. Set the Gas Control to the “OFF” position. Step 2.
ULN Res. D Series ECO (Energy Cut Out) The ICON System gas control is designed with an ECO device that will reset. To reset the gas control after a status code (4), turn the gas control knob to the “OFF” position and wait a minimum of (5) minutes before relighting following the instructions located on the lighting instruction label or the lighting instructions located in the installation and operation manual.
ULN Res. D Series Gas Control Removal From Water Heater Step 1. Position the gas control power switch to the “OFF” position and unplug heater from wall outlet. Step 2. Drain the heater to a point below the gas control level. Step 3. Turn off the gas supply to the water heater and disconnect gas piping from the gas control. Step 4. Disconnect damper and FVIR wire harnesses from the gas control. Step 5. Remove outer jacket door. Step 6.
ULN Res. D Series Flammable Vapor Testing Step 1. Position power switch on gas control to the “OFF” position. Step 2. Remove the outer door. Step 3. Disconnect the black wire leads from the FVIR sensor. Step 4. Using a multi-meter set to the ohms setting, check resistance of flammable vapor sensor. Resistance must be between 3,000 ohms and 48,000 ohms. If outside of this range replace Flammable Vapor Sensor. Step 5. Plug the black wire leads into either post, they are interchangeable. Step 6.
ULN Res. D Series Diptube Inspection & Replacement WARNING Water Heater components and stored water may be HOT when performing the following steps in this procedure. Take necessary precaution to prevent personal injury. Step 1. Position the on/off switch of the gas control valve to the “OFF” position and unplug the water heater from the wall outlet. Step 2. Turn off the cold water supply to the water heater. Connect a hose to the drain valve of the water heater and route to an open drain.
ULN Res. D Series Anode Inspection & Replacement WARNING Water Heater components and stored water may be HOT when performing the following steps in this procedure. Take necessary precaution to prevent personal injury. Step 1. Step 2. Step 3. Step 4. Step 5. Step 6. Step 7. 24 24 Position the on/off switch of the gas control valve to the “OFF” position and unplug the water heater from the wall outlet. Turn off the cold water supply to the water heater.
ULN Res. D Series Flue Baffle Inspection and Replacement Step 1. Step 2. Step 3. Position the on/off switch of the gas control valve to the “OFF” position and unplug the water heater from the wall outlet. Disconnect the vent system from the draft hood that is mounted on top of the damper. Remove the draft hood from the damper and retain it for later use. Step 4. Disconnect the cord sets from the damper. Step 5.
ULN Res. D Series Flue Baffle Inspection and Replacement (cont.) Step 6. Step 7. Step 8. Step 9. Step 10. Step 11. Step 12. Step 13. Step 14. Step 15. Step 16. Step 17. Step 18. Step 19. 26 26 Carefully remove the damper from the top of the water heater. Remove the flue baffle from the water heater. Inspect the baffle for deterioration and missing restrictors. Clean any scale or debris build-up. Replace with a new baffle, as necessary. Reinstall the baffle into the flue.
ULN Res. D Series Inner Door Removal Procedure Step 1. Step 2. Step 3. Step 4. Step 5. Step 6. Position gas control power switch to the “OFF” position. Remove outer jacket burner access door. Remove (2) ¼” hex drive screws from right side inner door. Remove (2) ¼” drive screws from flange section of inner door. Remove (3) ¼” drive screws from left side inner door. Remove inner door and inspect per step 7. Step 7.
ULN Res. D Series Step 9. Use RTV sealant (recommended bead size 1/8”) to secure the inner door gasket to the inner door sections (right & left). Refer to illustration below for proper application. Note the overlap configuration in the flange area of the inner door. Set the flange section first, this will help to achieve the proper overlap position. Installation of Inner Door With Gasket Step 10.
ULN Res. D Series Installation of Inner Door With Gasket (cont.) Step 13. Firmly place right side inner door flange against the left side inner door flange and secure with (2) ¼” hex drive screws from step 4. DO NOT OVER TIGHTEN SCREWS. Step 14. Align right side inner door to combustion chamber and verify the fastener holes of the combustion chamber are aligned with right side inner door slotted opening. Verify seal integrity around combustion opening.
ULN Res. D Series 115 VAC Circuit Trace Step 1. Verify 115 VAC and proper polarity at wall outlet. Step 2. With unit plugged in and control power switch in the “ON” position verify LED status. 30 30 WARNING 115 volt potential exposure. Use caution to avoid personal injury.
ULN Res. D Series Damper Relay Installation If the damper fails and the water heater operation is necessary temporarily, a relay, p/n 233-47642-00, and harness, p/n 239-51714-00, can be ordered from the Bradford White Service Parts Department. Step 1. Step 2. Step 3. Position the gas control power switch to the “OFF” position and unplug the water heater from the wall outlet. Disconnect the vent system from the draft hood that is mounted on top of the damper.
ULN Res. D Series Damper Relay Installation (cont.) Step 8. Step 9. Step 10. Step 11. Step 12. Step 13. Step 14. 32 32 Remove the Red wire in the damper housing from its location. Connect the ¼” Red female connector on the relay harness in its place Remove the Yellow wire in the damper housing from its location. Connect the ¼” Yellow female connector on the relay harness in its place. Remove the Blue wire in the damper housing from its location.
ULN Res. D Series Damper Relay Installation (cont.) Step 15. Step 16. Step 17. Step 18. Step 19. Step 20. Secure the damper housing cover in place using the screws from step 5. Re-install the draft hood from Step 3. Reconnect the vent system to the draft hood. Reconnect the cord sets from step 4. Plug the water heater into the wall outlet. Move the gas control power switch in to the “ON” position.
ULN Res. D Series Chamber Sensor Testing Step 1. Step 2. Step 3. Step 4. Step 5. Step 6. Step 7. Step 8. Position the gas control power switch to the “OFF” position and unplug the water heater from the wall outlet. Disconnect flammable vapor sensor harness from the gas control. Remove the outer door. Remove the chamber door temperature sensor from the right side inner door (Phillips screw driver). Make sure that the ring terminal of the chamber door temperature sensor is not touching any surface.
ULN Res. D Series Resettable Thermal Switch Continuity Testing Step 1. Step 2. Step 3. Step 4. Step 5. Remove outer jacket door. Disconnect black wire leads from the resettable thermal switch. Using a multimeter capable of measuring continuity (Ohms), place one probe of the meter on one of the brass connection tabs of the resettable thermal switch, and the remaining probe on the other connection tab. If continuity is indicated, the switch is closed, allowing millivolt current to pass.
ULN Res. D Series Resettable Thermal Switch Replacement Step 1. Step 2. Step 3. Step 4. Step 5. Step 6. Step 7. Rotate gas control knob to the “OFF” position. Remove outer jacket door. Disconnect the black wire leads from resettable thermal switch. Remove (2) ¼” hex drive screws from the manifold mount. Remove resettable thermal switch from manifold mount (Phillips screw driver). Place new resettable thermal switch in place.
ULN Res. D Series ScreenLok® Flame Arrestor Cleaning Step 1. Step 2. Step 3. Step 4. Step 5. Step 6. Step 7. Step 8. Position Gas Control power switch to the “OFF” position. Remove outer door. Remove outer jacket door and inner door per service procedure IX on page 26. Disconnect main burner feedline (3/4” wrench), pilot tube (7/16” wrench) and igniter/flame sensor wire from gas control and remove burner assembly from combustion chamber.
ULN Res. D Series Glossary of Terms BTU GPM Hz kWh LED NPT Ohms psi RPM ECO VAC “ w.c.
ULN Res. D Series 1. 2. 3. 4. 5. 6. 7. 8. Draft Diverter Damper Heat Trap Outlet Hot Water Outlet Anode Temp. and Pressure relief valve Heat Trap Inlet Flue Baffle Inlet Diptube 9. 10. 11. 12. 13. 14. 15. 16. Draft Diverter Damper Heat Trap Outlet Hot Water Outlet Anode Temp. and Pressure relief valve Heat Trap Inlet Flue Baffle Inlet Diptube 17. 18. 19. 20. 21. 22. 23. 24. Draft Diverter Damper Heat Trap Outlet Hot Water Outlet Anode Temp.
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