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The Bradford White
Flammable Vapor Ignition Resistant Water Heater
SERVICE
MANUAL
Troubleshooting Guide
and Instruction for Service
(To be performed ONLY by qualified service providers)
For the Bradford White
®
Defender Safety System Models:
MI30T*F(BN,CX) M430T*F(BN,CX)
MI30S*F(BN, CX) M440T*F(BN, CX)
MI303T*F(BN,CX) M4403S*F(BN,CX)
MI40T*F(BN,CX) M4403T*F(BN,CX)
MI403S*F(BN,CX) M450S*F(BN,CX)
MI404T*F(BN,CX) M4503*F(BN,CX)
MI503*F(BN,CX) M460T*F(BN,CX)
MI50L*F(BN,CX) M1XR403S*F(BN,CX)
MI504S*F
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FLAMMABLE VAPOR IGNITION RESISTANT WATER HEATERS Table of Contents Page Service Procedure Introduction 3 --- Trouble shooting Chart 4 - - - Inner Door Gasket Removal, Inspection, Replacement and Installation 5RG-I Thermocouple Testing and Replacement 8R G-II Pilot Assembly Inspection Cleaning and Replacement 10 RG-III Piezo Igniter and Electrode Testing 11 RG-IV Combination Thermostat/Gas Valve Testing and Replacement 12 RG-V Burner Operation Inspection, Adjustment, Cleaning and
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INTRODUCTION ® The Bradford White DEFENDER Safety System ® The Bradford White DEFENDER Safety System was designed to resist the ignition of flammable vapors that can occur outside of the water heater. Use and installation are nearly identical to previous versions of atmospherically fired and vented water heaters. A number of exclusive design features are incorporated in the system that will require additional knowledge on the part of the qualified service provider. The following information will
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TROUBLESHOOTING CHART Flammable Vapor Ignition Resistant Water Heaters SERVICE SYMPTOM PROBABLE CAUSE CORRECTIVE ACTION PROCEDURE 1. Turn on gas supply and/or check line 1. See Service Procedure 1. No incoming gas or too low gas pressure. RG-V, Page 12. pressure. 2. Review lighting instruction. Set 2. Gas control knob set to wrong position. combination/thermostat 4. See Service Procedure 3. Pilot light button not being fully gas valve to correct position. RG-III, P
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SERVICE PROCEDURE RG-I Inner Door/Gasket Removal, Inspection Replacement and Reinstallation For White Rodgers Control, depress knob slightly and rotate clockwise to the “OFF” position. Inner Door Removal Procedure Step 1. Rotate knob of the combination thermostat/gas valve to the “OFF” position. For Robertshaw Control, rotate knob clockwise to the “OFF” position. Step 2. Remove outer jacket burner access door Step 3. Inner Door Removal. a) Disconnect resettable thermal switch wire leads (le
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SERVICE PROCEDURE RG-I Inner Door/Gasket Removal, Inspection Replacement and Reinstallation Installation of Inner Door With Gasket. WARNING Step 7. Clean any residual gasket residue or other debris Stripped fastener connections may allow from combustion chamber surface before installing the inner door/gasket assembly. for seal breach of inner door. A seal breach may result in a fire or explosion Step 8. Place the left side inner door into position first. causing property damage, personal i
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SERVICE PROCEDURE RG-I Inner Door/Gasket Removal, Inspection Replacement and Reinstallation Step 10. Firmly place right side inner door flange against the left side inner door flange and secure with two ¼” drive screws from step 3c. DO NOT OVER TIGHTEN SCREWS. Step 11. Align right side inner door to combustion chamber and verify the fastener holes of the combustion chamber are aligned with the right side inner door slotted opening. Verify seal integrity around combustion opening. Secure right
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SERVICE PROCEDURE RG-II Thermocouple Testing and Replacement CLOSED CIRCUIT THERMOCOUPLE TESTING (White Rodgers Control) Step 1. Closed circuit testing is the preferred method for testing thermocouple. Following the lighting instruction label on the heater, proceed to light the pilot and allow to operate for three minuets. If the pilot will not stay lit, hold the pilot button (located on the combination thermostat/gas valve) down during this test Step 2. Using a multimeter capable of measuring
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SERVICE PROCEDURE RG-II Thermocouple Testing and Replacement OPEN CIRCUIT THERMOCOUPLE TESTING Step 1. Disconnect thermocouple from combination thermostat/gas valve. Step 2. Using a multimeter capable of measuring millivolts, connect one alligator clip to the end ball or contact portion of the thermocouple, and the other alligator clip to copper portion of the thermocouple. Step 3. Following the lighting instruction label on the heater, proceed to light the pilot and allow to operate for three
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SERVICE PROCEDURE RG-III Pilot Assembly Inspection, Cleaning and Replacement PILOT/ELECTRODE ASSEMBLY INSPECTION, CLEANING AND REPLACEMENT For White Rodgers Control, depress knob slightly and rotate clockwise to the “OFF” position. Step 1. Turn off gas supply to water heater. Rotate knob of combination thermostat/gas valve to “OFF” position. For Robertshaw Control, rotate knob clockwise to the “OFF” position. Step 2. Remove outer jacket door. Step 3. Remove right side of inner door per SERVI
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SERVICE PROCEDURE RG-IV Piezo Igniter, Electrode Testing and Replacement PIEZO IGNITER, ELECTRODE TESTING AND REPLACEMENT With the pilot not in operation (no pilot flame) you can check the Piezo and electrode circuit by viewing pilot thru the sight glass located on the inner door and observing the spark action. Step 1. Remove outer jacket door. Step 2. Repeatedly depress the Piezo igniter while viewing the pilot thru the sight glass. If a spark is present, the circuit is OK. If there is no spar
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SERVICE PROCEDURE RG-V Combination Thermostat/Gas Valve Testing and Replacement Combination Thermostat/Gas Valve Testing and Replacement The combination thermostat/gas valve is a non repairable device. If trouble shooting has determined a problem with the combination thermostat/gas valve, it must be replaced. If the burner and/or pilot do not function, service checks for gas pressure, thermocouple output, magnet assembly and ECO are to be performed. If these check OK, the combination thermosta
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SERVICE PROCEDURE RG-V Combination Thermostat/Gas Valve Testing and Replacement THERMOCOUPLE TESTING See SERVICE PROCEDURE RG-II MAGNET ASSEMBLY TESTING (White Rodgers Control) Step 1. Following the lighting instruction label on the heater, proceed to light the pilot and allow to operate for three minuets. If the pilot will not stay lit, hold the pilot button (located on the combination thermostat/gas valve) down during this test Step 2. Using a multimeter capable of measuring millivolts, co
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SERVICE PROCEDURE RG-V Combination Thermostat/Gas Valve Testing and Replacement ECO (Energy Cut Off) TESTING Step 1. Disconnect thermocouple from combination thermostat/gas valve. Step 2. Using a multimeter capable of measuring Ohms (or continuity), attach one lead (alligator clip) to the pilot tube. Insert the other lead (probe) fully into the magnet opening, Be sure the probe makes contact only at the top center of the magnet opening. Do not allow the probe to make contact with the threaded si
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SERVICE PROCEDURE RG-V Combination Thermostat/Gas Valve Testing and Replacement Step 7. Removal of combination thermostat/gas valve. a) Disconnect main burner feedline (¾” wrench), pilot tube (7/16" wrench) and thermocouple (3/8" wrench) from combination thermostat/gas valve & remove burner from combustion chamber. NOTE: Feed line nut for natural gas control uses right hand threads, LP control uses left hand thread. b) Remove piezo bracket with piezo igniter (refer to SERVICE PROCEDURE RG-I
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SERVICE PROCEDURE RG-V Combination Thermostat/Gas Valve Testing and Replacement Step 9. Reinstallation of inner door assembly. (cont.) b) Clean any gasket residue or other debris from combustion chamber surface before installing the inner door/gasket assembly. c) Position thermocouple, pilot tube and Piezo wire against left side inner door flange gasket. DO NOT ROUTE THROUGH RADIUSED CHANNEL WITH FEEDLINE. Be sure that thermocouple and pilot tube are not in position to interfere with
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SERVICE PROCEDURE RG-VI Burner Operation Inspection, Adjustment Cleaning and Replacement MAIN BURNER: Inspection, Adjustment, Cleaning and Replacement At periodic intervals (not more then 6 months) a visual inspection should be made of the main burner for proper operation and to insure no debris accumulating. Main burner should light smoothly from pilot and burn with a blue flame with a minimum of yellow tips. Steel burner models have a self adjusting air mixture and do not have an adjustable a
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SERVICE PROCEDURE RG-VI Burner Operation Inspection, Adjustment Cleaning and Replacement MAIN BURNER: Inspection, Adjustment, Cleaning and Replacement (cont.) Step 3. Fully inspect inner gasket per SERVICE PROCEDURE RG-I, step 4. Replace gasket if required following SERVICE PROCEDURE I, steps 5 & 6. Step 4. Be certain that thermocouple, pilot tube and piezo wire are routed by inner door flange as shown and Reinstall inner door per SERVICE PROCEDURE RG-I, step 10 and 11. Position thermocouple,
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SERVICE PROCEDURE RG-VI Burner Operation Inspection, Adjustment Cleaning and Replacement BURNER CLEANING (Cont.) Step 5. Disconnect (unscrew) Main burner (stamped steel “B” burner) from main burner orifice or on cast iron burners (“C” burner), loosen air shutter & disconnect (unscrew) feedline from burner. Step 6. Remove main burner orifice from feed line (½” wrench on steel burner, 3/8" wrench on cast iron). Inspect and clean if necessary. Step 7. Remove pilot assembly, refer to SERVICE PROCED
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SERVICE PROCEDURE RG-VII Resetting Thermal Switch Testing and Replacement RESETTABLE THERMAL SWITCH CONTINUITY TESTING Step 1. Remove outer jacket door. Step 2. Disconnect wire leads from resettable thermal switch. Step 3. Using a multimeter capable of measuring continuity (Ohms), place one probe of meter on one of the brass connection tabs of the resettable thermal switch, and the remaining probe on the other connection tab. Step 4. If continuity is indicated, the switch is closed, allowing mil
