The Bradford White R Through-The-Wall Gas Water Heaters SERVICE MANUAL (To be performed ONLY by qualified service providers) Troubleshooting Guide and Instructions for Service (To be performed ONLY by qualified service providers) For the Bradford White For Bradford White Through-The-Wall Models: TTW Series Models: M1TW40S* F (BN,CX) M1TW40S*(BN,CX)1 M1TW50S* F (BN,CX) M1TW50S*(BN,CX)1 M1TW60T* F (BN,CX) M2TW50T*(BN,CX)1 M2TW50T* F (BN,CX) M2TW65T*(BN,CX)1 M2TW65T* F (BN,CX) TW450S65(B)*(N,X) TW450S65 F (
The Bradford White Through-The-Wall Gas Water Heaters Page Page 2 TTW Service Procedure Introduction 4 --- How to use this manual 5 --- Tool required for service 5 --- Specifications 6 --- Control Timings 9 --- Sequence of Operation 10 --- Troubleshooting 13 --- Burner Inspection, Cleaning and Replacement 15 I Pilot Testing, Cleaning and Replacement 17 II Pressure Switch Testing and Replacement 18 III Blower Testing and Replacement 20 IV Blower Temperature Switch Testin
WARNING: If the information in these instructions is not followed exactly, a fire or explosion may result causing property damage, personal injury, or death. FOR YOUR SAFETY Do not store or use gasoline or other flammable, combustible, or corrosive vapors and liquids in the vicinity of this or any other appliance. 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.
Introduction The new Bradford White TTW1, TTW2 & TW4 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, additional vent lengths and Bradford White Defender Safety System®.
How to Use This Manual It is intended for this manual to be used by qualified service personal for the primary purpose of troubleshooting and repair of the Bradford White TTW Series water heaters. Understanding the sequence of operation section of this manual will contribute greatly to troubleshooting the water heater. The Honeywell WV4460E Electronic Gas Control will display error codes in the event of abnormal operation.
Specifications Power supply Dedicated 115VAC, 60 Hz, 15A Gas Supply Pipe Minimum 1/2" NPT (schedule 40 black iron pipe recommended) Approved Gas Type Natural or Propane. Unit must match gas type supplied. Gas Pressure 5.0" W.C. min. for Nat gas, 11.0" W.C. min. for L.P. gas, 14.0" W.C. maximum (Nat. & L.P.
Specifications Vent Tables Venting Specifications for: 40 Gallon 50 Gallon 60 Gallon 2" Diameter (5.1 cm) PVC Vent Connector Lengths Terminating # of Elbows Maximum Straight Length ft (m) Minimum Straight Length ft (m) Through the Wall 1 45 (13.7) 2 (.6) Through the Wall Through the Wall Through the Wall 2 3 4 40 (12.2) 35 (10.7) 30 (9.2) 2 (.6) 2 (.6) 2 (.6) Through the Roof Through the Roof Through the Roof Through the Roof 0 1 2 3 50 (15.2) 45 (13.7) 40 (12.2) 35 (10.7) 7 (2.1) 7 (2.
Specifications Vent Tables Venting Specifications for: 48 Gallon 65 Gallon 3" Diameter (7.6 cm) PVC Vent Connector Lengths Terminating # of Elbows Maximum Straight Length ft (m) Minimum Straight Length ft (m) Through the Wall Through the Wall 1 2 55 (16.8) 50 (15.2) 2 (.6) 2 (.6) Through the Wall Through the Wall 3 4 45 (13.7) 40 (12.2) 2 (.6) 2 (.6) Through the Roof Through the Roof Through the Roof Through the Roof 0 1 2 3 60 (18.3) 55 (16.8) 50 (15.2) 45 (13.7) 7 (2.1) 7 (2.1) 7 (2.
Specifications Specifications Control Timings Control Timings Ignition State Ignition State Timing Timing Pre-purge Pre-purge Trial for Ignition Trial for Ignition Flame Stabilization Period Flame Stabilization Period Inter-purge Inter-purge Flame Failure Response Time Flame Failure Response Time Post-purge Post-purge 2 Seconds 2 Seconds 90 Seconds 90 Seconds 3 Seconds 3 Seconds 15 Seconds 15 Seconds 1.5 Seconds (2 second. Maximum; 1 second minimum.) 1.5 Seconds (2 second. Maximum; 1 second minimum.
Sequence of Operation 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. To assure no outputs are energized if the “Flammable Vapor Sensor” is out of range, the control will test the “Flammable Vapor Sensor” for proper operating range. If the “Flammable Vapor Sensor” is within range the control resumes normal operation with no perceptible delay.
Sequence of Operation 7 Steady state operation. During Steady State Operation the Control Monitors: Thermostat temperature sensor- When set point temperature is satisfied, gas valve is shut down and blower will post purge for 15 seconds. Control LED flashes a short flash once every 4 seconds (idle) status code. Pressure switch / Blower temperature switch- If either switch opens, pilot valve and main valve is shut down. The blower continues to runs for 30 seconds attempting to close the circuit.
Sequence of Operation 3. Pressure Switch/Blower Temperature Fault: a) Pressure switch closed at start of call for heat - The gas control waits four seconds then, proceeds to flash 2 times with 3 second pause. The control waits 2 minutes and then turns on blower for 30 seconds. The blower turns off after 30 seconds and the control waits for pressure switch to open. Any time the Pressure switch opens, the blower turns on (or stays on) and the control proceeds to waiting for pressure switch to close.
Troubleshooting Green LED Indicator Observe green LED indicator on Electronic gas control. Error 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 Control Status Probable Cause None, control LED not on or flashing No electrical power Control power switch in “OFF” position. Supply voltage interrupted. Short flash, once every four seconds Stand-by mode, Waiting for call for heat (no fault).
Troubleshooting LED Status Control Status Six-one flash, three second pause Failed to light pilot. System auto resets. 1. Unstable pilot. 2. Pilot tube blocked or restricted. 3. Oxidation build up on pilot electrode. 4. Wire damage to pilot assembly or bad connection at gas valve. Six-two flash, three second pause Pressure switch or blower temp switch opened during burner operation. System auto resets. 1. Vent blockage or improper vent configuration. 2. Pressure switch tubing kinked or blocked. 3.
TTW SERVICE PROCEDURE I Burner Operation Inspection, Adjustment, Cleaning and Replacement Burner Inspection and Air Shutter Adjustment. 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.
TTW TTW SERVICE SERVICE PROCEDURE PROCEDURE II Burner Burner Operation Operation Inspection, Inspection, Adjustment, Cleaning and Adjustment, Cleaning and Replacement Replacement Burner Burner Cleaning Cleaning Remove Outer door. Step Step1. 1. Position Positiongas gascontrol controlpower powerswitch switchto tothe the “OFF” “OFF”position position and and unplug unplug heater heater from from wall wall outlet. outlet. Step Step2. 2. Turn Turnoff offgas gassupply supplyto towater waterheater. heater.
TTW SERVICE PROCEDURE II Pilot testing, Cleaning and Replacement Pilot Inspection, Testing and Replacement Step 1. Position gas control power switch to the “OFF” position and unplug heater from wall outlet. Remove Outer Step 2. Turn off gas supply to water heater. Step 3. innerinner door per Remove outer jacket door and slide doorservice open from left to procedure XIII on page 34. right. door. Slide inner door open from left to right. Igniter/flame sense wire Step 4.
TTW SERVICE PROCEDURE III Pressure Switch Testing and Replacement Pressure Switch Testing WARNING 115 volt potential exposure. Use caution making voltage checks to avoid personal injury. Step 1. Position power switch on gas control to the “OFF” position. Step 2. Remove the three screws (Phillips screw driver) from control access cover on blower assembly and remove cover (see photo 1). Step 3.
TTW SERVICE PROCEDURE III Pressure Switch Testing and Replacement Pressure Switch Replacement WARNING 115 volt potential exposure. Use caution to avoid personal injury. Step 1. Position gas control power switch to “OFF” position. Step 2. Remove the three screws (Phillips screw driver) from control access cover on blower assembly and remove cover (see photo 3). Pressure Switch 3 Step 3.
TTW SERVICE PROCEDURE IV Blower Testing and Replacement WARNING 115 volt potential exposure. Use caution when making voltage checks to avoid personal injury. Blower Testing Step 1. Position gas control power switch to “ON” position and adjust control to call for heat. Step 2. Remove the three screws (Phillips Screw driver) from control access cover on blower assembly and remove cover (see photo 7). Does blower energize Within 2 minutes? Y Connect manometer to pressure tap of blower.
TTW SERVICE PROCEDURE IV Blower Testing and Replacement Blower removal Step 1. Position gas control power switch to the “OFF” position. Step 2. Unplug blower power cord from wall outlet. Remove exhaust adapter and retain for use on new blower. Step 3. Disconnect vent system from exhaust adapter on top of blower. Step 4. Remove exhaust adapter from blower (blade screw driver) and retain for use on new blower Step 5. Unplug cord sets from blower. Step 6.
TTW SERVICE PROCEDURE V Blower Temperature Switch Testing and Replacement Blower Temperature Switch Testing. WARNING 115 volt potential exposure. Use caution to avoid personal injury. Step 1. Position power switch on gas control to the “OFF” position. Step 2. Remove the three screws (Phillips screw driver) from control access cover on blower and remove cover (see photo 14). Step 3.
TTW SERVICE PROCEDURE V Blower Temperature Switch Testing and Replacement Blower Temperature Switch Replacement. WARNING 115 volt potential exposure. Use caution to avoid personal injury. Step 1. Position gas control power switch to the “OFF” position and unplug heater from wall outlet. Step 2. Remove the three screws (Phillips screw driver) from the control access cover on blower and remove cover. (see photo 16) Step 3. 16 Locate blower temperature switch (see photo 17) 17 Step 4.
TTW SERVICE PROCEDURE VI Gas Control/Thermal Well Testing and Replacement Gas Control Testing See pages 29 & 30 for gas control voltage testing. Thermal Well Testing Disconnect thermal well wire harness If Control has gone into TCO lockout due to excessive tank temperature (four flash, 3 second pause) reset control by rotating knob of temperature control to the minimum setting for at least 6 seconds before returning to desired temperature setting. Observe heater operation.
TTW SERVICE PROCEDURE VI Gas Control/Thermal Well Testing and Replacement WARNING Stored water may be HOT when performing the following steps in this procedure. Take necessary precaution to prevent personal injury. Determine Water Temperature Inside Tank Note: It is important to understand once the resistance for the thermal well is determined from page 24, water flow through the heater should not occur. Prior to performing the steps below, turn off the cold water supply to the water heater.
TTW SERVICE PROCEDURE VI Gas Control & Thermal Well Testing and Replacement Gas Control & Thermal Well Removal From Water Heater Gas Control Gas Control Step 1. Position gas valve power switch to the “OFF” position and Unplug Heater from power supply. Step 2. Drain heater to a point below the gas control level. Step 3. Turn off gas supply to water heater and disconnect gas piping from gas control. Step 4. Disconnect wire harnesses and burner assembly from gas control. Step 5.
TTW SERVICE PROCEDURE VI Gas Control & Thermal Well Testing and Replacement Gas Control Assembly to Thermal Well Step 1. Install threaded end of thermal well into tank. Be sure thermal well flange is positioned as shown in photo 24 for proper control alignment. Step 2. Route wire leads back into relief opening. (see photo 24) Step 3.
TTW SERVICE PROCEDURE VII Flammable Vapor Device Testing Flammable Vapor Device Testing Step 1. Position power switch on gas control to the “OFF” position. Step 2. Disconnect flammable vapor sensor from gas control. Step 3. Using a multi-meter set to the ohms setting check resistance of flammable vapor sensor. (see caution below) Resistance must be within 3,000 ohms and 48,000 ohms. If outside of this range replace flammable vapor sensor.
TTW SERVICE PROCEDURE VIII Safety Circuit Voltage Trace Safety Circuit Voltage Trace WARNING 115 volt potential exposure. Use caution making voltage checks to avoid personal injury. NOTE: This procedure assumes a cool tank. 26 Remove three screws (Phillips Screw driver) from control access cover on blower and remove cover (see photo 26).
TTW SERVICE PROCEDURE IX 115 VAC Trace WARNING 115 volt potential exposure. Use caution making voltage checks to avoid personal injury. 115 VAC Circuit Trace Step 1. Verify 115VAC and proper polarity at wall outlet. Step 2. With unit plugged in and control power switch in the “ON” position verify LED status. LED status None, Control LED not on or flashing. LED status Short flash, once every four seconds. LED status “Heartbeat”, alternates bright/dim. LED status Various flashing error codes.
TTW SERVICE PROCEDURE X Dip Tube Inspection and replacement Dip Tube Inspection and 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 on/off switch of gas control valve to “OFF” position and unplug water heater from wall outlet. Step 2. Turn off cold water supply to water heater. Connect hose to drain valve of water heater and route to an open drain.
TTW SERVICE PROCEDURE XI Anode Inspection and replacement Anode Inspection and 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 on/off switch of gas control valve to the “OFF” position and unplug water heater from wall outlet. Step 2. Turn off cold water supply to water heater. Connect hose to drain valve of water heater and route to an open drain.
TTW SERVICE PROCEDURE XII Flue Baffle Inspection and replacement Remove blower to gain access to flue baffle Disconnect vent system from exhaust adapter. Step 1. Position gas control power switch to the “OFF” position and unplug blower from wall outlet. Step 2. Disconnect vent system from exhaust adapter on top of blower. Step 3. Unplug cord sets from blower. (see photo 33). Step 4. Remove the three blower mounting screws (¼" nut driver) (see photo 33). Step 5.
TTW SERVICE PROCEDURE XIII Inner Door/Gasket Removal, Inspection Replacement and Reinstallation Inner Door Removal Procedure Step 1. Position gas control power switch to the “OFF” position. Step 2. Remove outer jacket burner access door Step 3. Inner Door Removal. a) Remove (2) 1/4" hex drive screws from right side inner door. b) Remove (2) 1/4" drive screws from flange section of inner door. c) Remove (2) 1/4" drive screws from left side inner door. d) Remove inner door and inspect per step 4.
TTW SERVICE PROCEDURE XIII 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. Step 8. Place the left side inner door into position first. Firmly position the radiused channel of the inner door around the feedline. Using the 1/4” hex drive screws from step 3c, secure left side inner door in place.
TTW SERVICE PROCEDURE XIII 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 3b. 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.
ScreenLok® Flame Arrestor Cleaning ScreenLok® Flame Arrestor Cleaning: Step 1. Position Gas Control Power Switch to the OFF position. Step 2. Remove outer jacket. Step 3. Remove inner door per TTW SERVICE PROCEDURE XIII, step 3a through step 3d. Step 4. Disconnect main burner feed line (3/4 wrench), pilot tube (7/16 wrench) and igniter/flame sensor wire from gas control and remove burner assembly from combustion chamber. Step 5.
Glossary of Terms BTU GPM Hz KW/h LED NPT Ohms PSI RPM TCO VAC W.C.
Parts List 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. Blower Complete Air Mixing Inlet cover Pressure Switch Blower Temp. Switch Blower Gasket Blower Power Cord Vent Adapter w/vent term. Condensate Hose Kit Flue Reducer (M2 only) Heat Trap Outlet Hot Water Outlet Anode Flue Baffle 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. Heat Trap Inlet Inlet Dip Tube Wire Harness T&P Valve ¾ NPT Plug Burner Assy. (Nat) Burner Head Main Burner Orifice Pilot Assy. (Nat) Pilot Orifice Feedline Burner Assy. (L.P.) 25.
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