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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)2 M430T*F(BN,CX)2
MI30S*F(BN,CX)2 M4403S*F(BN,CX)2
MI303T*F(BN,CX)2 M4403T*F(BN,CX)2
MI40T*F(BN,CX)2 M450S*F(BN,CX)
MI403S*F(BN,CX)2 M1XR403S*F(BN,CX)2
MI404T*F(BN,CX)2 M1XR504T*F(BN,CX)2
MI503*F(BN,CX)2 M2XR504T*F(BN,CX)2
MI50L*F(BN,CX)2 M2C504T*F(BN,CX)
MI504S*
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Flammable Vapor Ignition Resistant Water Heater Table of Contents Page Service Procedure Introduction 3 - - - Trouble shooting Chart 4 - - - Inner Door Gasket Removal, Inspection, Replacement and Installation 5 RG-I Thermocouple Testing and Replacement 8 RG-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 Replacement 17
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Introduction ™ The Bradford White DEFENDER Safety System TM 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 wil
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Troubleshooting Chart Flammable Vapor Ignition Resistant Water Heaters SERVICE SYMPTOM PROBABLE CAUSE CORRECTIVE ACTION PROCEDURE 1. See Service Procedure 1. No incoming gas or too 1. Turn on gas supply and/or check line pressure. RG-V, Page 12. low gas pressure. 2. Review lighting instruction. 2. Gas control knob set Set combination/thermostat gas valve to correct 4. See Service Procedure to wrong position. position. RG-III, Page 10. 3. Pilot light button not being fully Pilot Will 3. Revie
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SERVICE PROCEDURE RG-I Inner Door/Gasket Removal, Inspection Replacement and Reinstallation Inner Door Removal Procedure Step 1. Rotate knob of the combination thermostat/gas valve to the “OFF” position. Step 2. Remove outer jacket burner access door Step 3. Inner Door Removal. a) Disconnect resettable thermal switch wire leads (leading from combination thermostat/gas valve). b) Remove (2) 1/4" hex drive screws from right side inner door. c) Remove (2) 1/4" drive screws from flange section of in
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SERVICE PROCEDURE RG-I Inner Door/Gasket Removal, Inspection Replacement and Reinstallation Installation of Inner Door with Gasket Step 7. Clean any residual gasket residue or other debris from combustion chamber surface before installing the inner door/gasket assembly. ! ! WARNING Stripped fastener connections may Step 8. Place the left side inner door into position first. allow for seal breach of inner door. A Firmly position the radiused channel of the inner seal breach may result in a f
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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 1/4” 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 com- bustion chamber opening. S
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SERVICE PROCEDURE RG-II Thermocouple Testing and Replacement Closed Circuit Thermocouple Testing Step 1. Disconnect thermocouple from combination thermostat/gas valve. Step 2. Connect a thermocouple adapter (BWC P/N 239-44642-00, Robertshaw P/N 75036) at the thermocouple location in the combination thermostat/gas valve. Step 3. Reconnect thermocouple to adapter. make certain all connections are tight (finger tight plus 1/4 turn) Step 4. Using a multimeter capable of measuring millivolts, conn
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SERVICE PROCEDURE RG-II Thermocouple Testing and Replacement Thermocouple Replacement Step 1. Turn off gas supply to water heater. Rotate knob of combination thermostat/gas valve to “OFF” position. Step 2. Remove outer jacket door. Step 3. Remove right side of inner door per SERVICE PROCEDURE RG-I, steps 3a through 3c. Step 4. Disconnect thermocouple from combination thermostat/gas valve (3/8" wrench). Locate other end of thermocouple inside of combustion chamber and remove from pilot bracket
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SERVICE PROCEDURE RG-III Pilot Assembly Inspection, Cleaning and Replacement Pilot/Electrode Assembly Inspection, Cleaning and Replacement Step 1. Turn off gas supply to water heater. Rotate knob of combination thermostat/gas valve to “OFF” position. Step 2. Remove outer jacket door. Step 3. Remove right side of inner door per SERVICE PROCEDURE RG-I, steps 3a through 3c. Step 4. Disconnect thermocouple from combination thermostat/gas valve (3/8" wrench). Disconnect pilot tube from combination
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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 thermostat
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SERVICE PROCEDURE RG-V Combination Thermostat/Gas Valve Testing and Replacement THERMOCOUPLE TESTING See SERVICE PROCEDURE II MAGNET ASSEMBLY TESTING Step 1. Disconnect thermocouple from combination thermostat/gas valve. Step 2. Connect a thermocouple adapter (BWC P/N 239-44642-00, Robertshaw P/N 75036) at the thermocouple location in the combination thermostat/gas valve. Step 3. Reconnect thermocouple to adapter. Make certain all connections are tight (finger tight plus 1/4 turn). Step 4. Us
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SERVICE PROCEDURE RG-V Combination Thermostat/Gas Valve Testing and Replacement COMBINATION THERMOSTAT/GAS VALVE REPLACEMENT Step 1. Rotate knob of the combination thermostat/gas valve to the “OFF” position. Step 2. Turn off gas supply to water heater. Step 3. Disconnect gas supply line from combination thermostat/gas valve. Step 4. Turn off water supply and drain water heater completely. Step 5. Remove outer jacket burner access door. Step 6. Right side inner door removal. a) Disconnect resetta
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SERVICE PROCEDURE RG-V Combination Thermostat/Gas Valve Testing and Replacement Step 7. Removal of combination thermostat/gas valve. Refer to SERVICE PROCEDURE RG-IV to remove Piezo igniter a) Disconnect main burner feedline (3/4” wrench), pilot tube (7/16" wrench) and thermocouple (3/8" wrench) from combination thermostat/gas valve & remove from the combustion chamber. b) Remove Piezo bracket with Piezo igniter (refer to SERVICE PROCEDURE RG-IV) from combination thermostat/gas valve. c)
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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 outer jack
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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 opera- tion 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
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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 (1/2” wrench on steel burner, 3/8" wrench on cast iron). Inspect and clean if necessary. Step 7. Remove pilot assembly, refer to SERVICE P
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SERVICE PROCEDURE RG-VII Resettable 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
