Bradford White EF120T4003N3 Service Manual

Bradford White EF120T4003N3 Service Manual

Commercial ultra high efficiency models with direct spark ignition

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Commercial Ultra High Efficiency Models
with Direct Spark Ignition
Manual 238-53597-00B REV 5/20
SERVICE
MANUAL
Troubleshooting Guide
and Instructions for Service
(To be performed ONLY by
qualified service providers)
Models Covered
by This Manual:
EF120T4003N(A)3
EF120T5003N(A)3
Effective: April, 2020
ECO 8160
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Summary of Contents for Bradford White EF120T4003N3

  • Page 1 Commercial Ultra High Efficiency Models with Direct Spark Ignition SERVICE MANUAL Troubleshooting Guide and Instructions for Service (To be performed ONLY by qualified service providers) Models Covered by This Manual: EF120T4003N(A)3 EF120T5003N(A)3 Effective: April, 2020 ECO 8160 Manual 238-53597-00B REV 5/20 Save this manual for future reference...
  • Page 2: Table Of Contents

    Ultra High Efficiency Models with Direct Spark Ignition Table of Contents Introduction…………………………………………………………………………………..3 How to Use This Manual……………………………………………………………………..4 Tools Required for Service…………………………………………………………………..4 Features………………………………………………………………………………………..5 Specifications…………………………………………………………………………………. ..6 Sequence of Operations……………………………………………………………………… ..9 Building Management System (BMS)………………………………………………………..10 Troubleshooting………………………………………………………………………………. .11 Service Procedure I: Thermostat Circuit Testing and Replacement……………………. .19 Service Procedure II: Combustion System Testing and Replacement………………..23 Service Procedure III: Burner Tube Inspection and Replacement………………………..27 Service Procedure IV: Gas Valve Replacement……………………………………………...
  • Page 3: Introduction

    Introduction The 120T Ultra High Efficiency Water Heater is designed to deliver a high thermal efficiency rating, in a quiet running unit with venting options that allow for installation flexibility. Several technologically advanced design features are incorporated in the design that will require additional knowledge on the part of the qualified service provider.
  • Page 4: Tools Required For Service

    Tools Required for Service Manometer: Two types available, a liquid “U” tube type or a digital (magnehelic) type. This device is used to measure gas and/or air pressures and vacuum. Multi-Meter: A digital type is strongly recommended. This device is used to measure electrical values. The meter must have the capability to measure volts AC, volts DC, amps, micro-amps, and ohms.
  • Page 5: Specifications

    Specifications DIMENSIONS (INCHES) Storage Input Capacity Floor to Alt. Floor to Floor to Floor to Floor to Model No. Rate Floor to Top U.S. Height Hot Water Dia. Vent Inlet T&P Hot Outlet BTU/h of Heater Gallons Outlet Outlet Water Conn. Valve Conn.
  • Page 6 Specifications Power Supply Dedicated 120 VAC, 60 Hz, (15A GFI recommended) Minimum 1 in. NPT Gas Supply (schedule 40 black iron pipe recommended) Approved Gas Type Natural 14” W.C. maximum static, 4.5” W.C. minimum running Gas Pressure (Nat.) (recommend 7” W.C. min running) Power vent, balanced direct vent or unbalanced direct Venting System vent.
  • Page 7 Specifications Vent Tables Power Direct Vent and Power Vent Maximum Vent Length (Combined Maximum Length for Intake and Exhaust) Air intake CANNOT exceed exhaust by more than 30 ft 120T-400-3N(A) 399,999 BTU/hr 120T-500-3N(A) 499,000 BTU/hr 3 in. Vent Pipe Power Direct Vent Power Vent Power Direct Vent Power Vent...
  • Page 8: Sequence Of Operations

    Sequence of Operations Thermostat calls for heat. Combustion blower starts at a 3,000 RPM “soft” start light off. Blower pre-purge period of approximately 15 seconds. Ignition control board runs an internal verification safety check for approximately 15 seconds. Trial for ignition (approximately 5 seconds per trial, 3 trials total): a.
  • Page 9 Sequence of Operations Lockout Conditions The system will go into lock out mode for the following reasons: 1. ERROR CODE 110 a. Control board will go into soft lockout if the main burner cannot be lit or fails to prove flame after 3 ignition trials.
  • Page 10: Building Management System (Bms)

    Building Management System (BMS) The 120T can be equipped with a gateway kit that will facilitate a Building Management System (BMS) connection to Modbus or Bacnet ® . This kit is sold separately and is not factory installed. A full installation, operation, and troubleshooting manual is provided with the gateway kit.
  • Page 11: Troubleshooting

    Troubleshooting System Observation for 120T400/500 Models with Direct Spark Ignition Water Heater Fault: Water heater does NOT operate. WARNING Display Error Code: Water heater digital display does 120 volt potential exposure. Use caution making NOT operate - blank display. voltage checks to avoid personal injury. Check main power supply to water heater.
  • Page 12 Troubleshooting CAUTION WARNING Use caution to NOT damage connectors when 120 volt potential exposure. Use caution making making voltage measurements or jumping terminals. voltage checks to avoid personal injury. Continued from Error code 62 on display. Measure voltage previous page. Verify 120V from power switch.
  • Page 13 Troubleshooting WARNING The following procedure is for service and installation personnel only. Resetting lockout conditions without correcting the malfunction can result in a hazardous condition. Water Heater Display and Control Buttons Step 1: Press and hold the lower right button under “Next” in the lower right display for at least 3 seconds. Step 2: The digital display will show the flame sense current in microamps when the burner is operating.
  • Page 14 Troubleshooting Step 4: Press lower right “Next” button and the digital display will flash and show the number of any Lockout codes. Step 5: Press lower right “Next” button and the digital display will show the temperature sensor reading. Step 6: Press lower right “Next” button and the digital display will show the manual firing rate adjustment. This function is not currently used.
  • Page 15 Troubleshooting To Increase Setpoint Temperature Step 1: Press and hold “Temperature Up” button until desired setpoint temperature appears on the display. Step 2: Press “DONE” button for new setting to take effect immediately. If the “DONE” button is not pressed, the new temperature setting will take effect in approximately 10 seconds.
  • Page 16 Troubleshooting Step 2: Press “DONE” button for new setting to take effect immediately. If the “DONE” button is not pressed, the new temperature setting will take effect in approximately 10 seconds. NOTICE Pressing the “NEXT” button instead of “DONE” will enter the display to show unused screens such as “Stack ----F, Outdoor ----F, % Rate (Shows percentage of full input rate for Lightoff rate), Outlet ----F, Inlet ----F, Delta T ----F.
  • Page 17 Troubleshooting SERVICE ERROR CODES AND TROUBLESHOOTING PROCEDURES FOR 120T400/500 MODELS WITH HONEYWELL LOW FIRE START CONTROL SYSTEM Definition Error Code Cause of Problem and Actions Taken to Correct of Code Check power supply to the water heater. Make sure the water heater is plugged in and the breaker is on. No code –...
  • Page 18 Troubleshooting Check the wiring from the sensor to the control board. Measure the resistance of each outside wire to the center wire (resistance chart found on High limit pg 21). (overheat If either outside wire has a much different resistance reading, replace the sensor. condition) Make sure the sensor is securely held inside the well with the clip.
  • Page 19 Service Procedure I: Thermostat Circuit Testing and Replacement IMPORTANT NOTE: This procedure assumes a cool tank. WARNING Condition: Water heater not operating. Digital display 120 volt potential exposure. Use caution shows error code 93 (sensor reading faulty). making voltage checks to avoid personal injury. CAUTION Unplug or disconnect electrical power to the water heater.
  • Page 20 Service Procedure I: Thermostat Circuit Testing and Replacement Continued from previous page. WARNING DO NOT operate the water heater without verifying that the overheating condition has Condition: Water heater not operating. Digital been corrected. display shows error code 80 high water temperature (over 200°F) (continued from previous page).
  • Page 21 Service Procedure I: Thermostat Circuit Testing and Replacement APPENDIX-A Sensor Resistance at Various Temperatures Be careful when making voltage measurements or jumping terminals not to damage or deform connectors or connector pins. Draw water from the temperature and pressure relief valve. Compare temperature with temperature ohms chart below. Example: If the temperature is 84°F, then the resistance through the sensor would be 8449 (see shaded area).
  • Page 22 Service Procedure I: Thermostat Circuit Testing and Replacement Thermostat Sensor (Thermistor) Replacement Procedure WARNING 1. Position main power switch to “OFF.” 120 volt potential exposure. Use 2. Disconnect (unplug) water heater from 120 volt power source. caution making voltage checks to avoid personal injury.
  • Page 23 Service Procedure II: Combustion System Testing and Replacement Observe burner operation through the sight glass located on the combustion insert mounting flange. Normal burner operation should ignite smoothly, without evidence of coughing or huffing upon ignition. The burner flame should be a blue flame near the burner surface in a uniform flame pattern.
  • Page 24 Service Procedure II: Combustion System Testing and Replacement Observe burner operation through the sight glass located on the combustion insert mounting flange. Normal burner operation should ignite smoothly, without evidence of coughing or huffing upon ignition. The burner flame should be a blue flame near the burner surface in a uniform flame pattern.
  • Page 25 Service Procedure II: Combustion System Testing and Replacement WARNING WARNING Heater components may be HOT when performing 120 volt potential exposure. Use caution making the following steps in this procedure. Take necessary voltage checks to avoid personal injury. precaution to prevent personal injury. Combustion System Removal Procedure 1.
  • Page 26 Service Procedure II: Combustion System Testing and Replacement Combustion System Replacement Procedure 1. Fully inspect burner mounting insert gasket for the following: a. Tears d. Dirt or debris b. Missing material e. Other imperfections that would inhibit proper seal c. Cracks If gasket is NOT affected by any of the above, gasket replacement is not required.
  • Page 27 Service Procedure III: Burner Tube Inspection and Replacement WARNING WARNING Heater components may be HOT when performing 120 volt potential exposure. Use caution making the following steps in this procedure. Take voltage checks to avoid personal injury. necessary precaution to prevent personal injury. Burner Tube Removal Procedure 1.
  • Page 28 Service Procedure III: Burner Tube Inspection and Replacement WARNING Heater components may be HOT when performing the following steps in this procedure. Take necessary precaution to prevent personal injury. Burner Tube Inspection 1. Inspect burner tube (metal fiber mesh burner) for the following: a.
  • Page 29 Service Procedure IV: Gas Valve Replacement Gas Valve Replacement Procedure WARNING 1. Position main power switch to OFF. 120 volt potential exposure. Use 2. Disconnect (unplug) water heater from 120 volt power source. caution making voltage checks to avoid personal injury. 3.
  • Page 30: Service Procedure V: Blower Testing And Replacement

    Service Procedure V: Blower Testing and Replacement Are collector high limit Does blower energize? Refer to ignition switch and pressure Ensure digital display control board Replace ignition shows “Heating.” Raise switches in normally illustration below. Is control board. closed position? there 24-28VAC temperature setpoint if between blue and...
  • Page 31 Service Procedure V: Blower Testing and Replacement Blower Replacement Procedure WARNING 1. Position main power switch to OFF. 120 volt potential exposure. Use caution 2. Disconnect (unplug) water heater from 120 volt power source. making voltage checks to avoid personal 3.
  • Page 32 Service Procedure VI: Blocked Vent Pressure Switch Testing and Replacement The blocked vent pressure switch monitors the pressure in the exhaust tube. The switch contacts are normally closed and will not open unless there is a blockage in the exhaust venting or terminal (snow, ice, debris). If the blocked vent pressure switch contacts open after the thermostat initiates the blower, the blower will remain on for up to 5 minutes waiting for the contacts to close.
  • Page 33 Service Procedure VI: Blocked Vent Pressure Switch Testing and Replacement Check Exhaust Tube Pressure Is exhaust venting With manometer, take a Clear obstruction. system blocked or reading at the exhaust tube Determine cause obstructed? Also pressure tap location. Is and correct. check condensate value .4”...
  • Page 34 Service Procedure VI: Blocked Vent Pressure Switch Testing and Replacement Exhaust Pressure Switch Replacement Procedure 1. Position main power switch to OFF position. 2. Loosen adhesive backed rubber escutcheon from service panel access cover and slide escutcheon back along exhaust pipe to allow for removal of cover. 3.
  • Page 35: Service Procedure Vii: Flame Sensor Testing And Replacement

    Service Procedure VII: Flame Sensor Testing and Replacement WARNING Flame Sensor Testing Procedure 120 volt potential exposure. Use caution making voltage checks to avoid personal injury. Flame sensor may be HOT, take necessary precautions. Refer to image below. Is there a minimum of 1 μA during 2 second flame proving period? (may be Refer to ignition control board...
  • Page 36 Service Procedure VII: Flame Sensor Testing and Replacement Flame Sensor Replacement Procedure WARNING 1. Position main power switch to OFF. 120 volt potential exposure. Use 2. Disconnect (unplug) water heater from 120 volt power source. caution making voltage checks to avoid personal injury.
  • Page 37 Service Procedure VIII: Spark Rod Gap Adjustment and Replacement Spark Rod Gap Inspection and Adjustment WARNING 1. Remove combustion system as described in Spark gap must be set from 3/16” to 1/4". Combustion System Removal Procedure (pg 25). Failure to set and verify proper spark gap 2.
  • Page 38 Service Procedure VIII: Spark Rod Gap Adjustment and Replacement WARNING WARNING If the spark rod is replaced for any reason, the combustion 120 volt potential exposure. Use caution making system MUST be removed and the spark gap to the burner voltage checks to avoid personal injury.
  • Page 39: Service Procedure Ix: Ignition Control Board Replacement

    Service Procedure IX: Ignition Control Board Replacement Control Board Replacement WARNING 1. Position main power switch to OFF. 120 volt potential exposure. Use caution making voltage checks 2. Disconnect (unplug) water heater from 120 volt power source. to avoid personal injury. 3.
  • Page 40: Service Procedure X: Transformer Replacement

    Service Procedure X: Transformer Replacement Transformer Replacement Procedure WARNING 1. Position main power switch to OFF. 120 volt potential exposure. Use 2. Disconnect (unplug) water heater from 120 volt power source. caution making voltage checks to avoid personal injury. 3. Unlatch and remove surround cover from top of water heater. 4.
  • Page 41 Service Procedure XI: Vent Safety Switch Testing and Replacement Error code 67 will display, indicating an open circuit for the vent safety switch. Determine if temperature has reached 190°F before resetting switch and restoring operation. If evidence of extreme temperature is present, call Technical Support. WARNING WARNING Make sure exhaust collector compartment or exhaust...
  • Page 42 Service Procedure XI: Vent Safety Switch Testing and Replacement Vent Safety Switch Replacement Procedure 1. Position main power switch to OFF. 2. Loosen the adhesive backed rubber escutcheon from service panel access cover. Slide the escutcheon back along the exhaust pipe to allow for removal of cover (see images below). 3.
  • Page 43 Service Procedure XII: Power Anode Inspection and Replacement WARNING Heater components may be HOT when performing the following steps in this procedure. Take necessary precaution to prevent personal injury. Powered Anode Replacement The powered anode control board is located on the right vertical side of the control board inside the surround panel. The control board has a LED indicator light to show the status of operation.
  • Page 44: Water Heater Installation Checklist

    Water Heater Installation Checklist Carefully uncrate the heater. Move in place with a hand truck (DO NOT use the venting Product Handling pipes for handles). Make sure there is 120 volts line voltage. Line voltage must be properly polarized. Electrical Requirements Adequate ground supplied to the heater.
  • Page 45: Water Heater Service Report

    Water Heater Service Report Date: _______________ Service Provider: _____________________________ Model Number: ______________________________ Phone Number: ______________________________ Serial Number: ________________________________ Venting (PVC, CPVC): Vent size 4”, 6” ______ Intake 45° Elbows (qty) ______ Length of Straight Pipe Intake 90° Elbows (qty) ______ Exhaust 45°...
  • Page 46: Glossary Of Terms

    Glossary of Terms Alternating Current Oxides of Nitrogen BTU/H British Thermal Units National Pipe Thread Carbon Monoxide Pounds per Square Inch Carbon Dioxide Revolutions per Minute Direct Current Volt Amps Direct Spark Ignition Volts Alternating Current Energy Cut Off W.C. Inches of Water Column Ground Fault Interrupt °C...
  • Page 47 Notes _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________...

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