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Manual 238-46238A-00A
TTW Series
Through-The-Wall Gas Water Heaters
®
SERVICE
MANUAL
Troubleshooting Guide
and Instructions for Service
(To be performed ONLY by
qualified service providers)
Models Covered
by This Manual:
M1TW40S*F (BN,CX,SX)
M1TW50S*F (BN,CX,SX)
M1TW60T*F (BN,CX,SX)
M4TW40T*F (BN,SX)
M4TW50T*F (BN,SX)
M4TW60T*F (BN,SX)
M2TW50T*F (BN,CX,SX)
M2TW65T*F (BN,CX,SX)
TW450S65F (B,C,S)*(N,X)
TW465S65F (B,C,S)*(N,X)
(*) Denotes Warranty Years
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Table of Contents
Related Manuals for Bradford White M1TW40S Series
Summary of Contents for Bradford White M1TW40S Series
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Page 1: Troubleshooting Guide
® TTW Series Through-The-Wall Gas Water Heaters SERVICE MANUAL Troubleshooting Guide and Instructions for Service (To be performed ONLY by qualified service providers) Models Covered by This Manual: M1TW40S*F (BN,CX,SX) M1TW50S*F (BN,CX,SX) M1TW60T*F (BN,CX,SX) M4TW40T*F (BN,SX) M4TW50T*F (BN,SX) M4TW60T*F (BN,SX) M2TW50T*F (BN,CX,SX) M2TW65T*F (BN,CX,SX) TW450S65F (B,C,S)*(N,X) - Page 2 The Bradford White Through-The-Wall Gas Water Heaters Page TTW Service Procedure Introduction - - - How to use this manual - - - Tool required for service - - - Specifications - - - Control Timings - - - Sequence of Operation - - - Troubleshooting - - -...
- Page 3 CAUTION WARNING: If the information in these instructions Incorrect operation of this appliance is not followed exactly, a fire or explosion may may create a hazard to life and result causing property damage, personal injury, or property and will nullify the warranty. death.
- Page 4 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 and additional vent lengths. Spark to Pilot Ignition System - employing the spark to pilot ignition system promotes reliable and consistent pilot and main burner ignitions to provide hot water on demand.
- Page 5 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.
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Page 6: Specifications
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.) Venting System Power vent through the wall or vertical through the roof Approved Vent Materials... -
Page 7: Vent Tables
Specifications Vent Tables Venting Specifications for: 40 Gallon 50 Gallon 60 Gallon 2" Diameter (5.1 cm) PVC Vent Connector Lengths # of Maximum Straight Minimum Straight Terminating Elbows Length ft (m) Length ft (m) Through the Wall 45 (13.7) 2 (.6) Through the Wall 40 (12.2) 2 (.6) - Page 8 Specifications Vent Tables Venting Specifications for: 48 Gallon 65 Gallon 3" Diameter (7.6 cm) PVC Vent Connector Lengths # of Maximum Straight Minimum Straight Terminating Elbows Length ft (m) Length ft (m) Through the Wall 55 (16.8) 2 (.6) Through the Wall 50 (15.2) 2 (.6) Through the Wall...
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Page 9: Control Timings
Specifications Control Timings Ignition State Timing Pre-purge 2 Seconds Trial for Ignition 90 Seconds Flame Stabilization Period 3 Seconds Inter-purge 15 Seconds Flame Failure Response Time 1.5 Seconds (2 second. Maximum; 1 second minimum.) Post-purge 15 Seconds PS Fault Delay (failed open/close) Retry after 2 Minutes Soft Lockout Retry after 5 Minutes... -
Page 10: Sequence Of Operation
Sequence of Operation Start Up. Upon power up, the control runs a safe-start check with a typical start-up delay of 5 seconds. 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”... - Page 11 Sequence of Operation 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.
- Page 12 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.
- Page 13 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. Control Service LED Status Probable Cause Status Procedure...
- Page 14 Troubleshooting Control Service LED Status Probable Cause Status Procedure 1. Unstable pilot. 1. Page 15 Failed to light 2. Pilot tube blocked or restricted. Six-one flash, three pilot. 3. Oxidation build up on pilot electrode. 2-4. Page 17 second pause System auto 4.
- Page 15 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.
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Page 16: Burner Cleaning
TTW SERVICE PROCEDURE I Burner Operation Inspection, Adjustment, Cleaning and Replacement Burner Cleaning Burner Cleaning Remove Outer door. Step 1. Position gas control power switch to the Step 1. Position gas control power switch to the “OFF” position and unplug heater from wall “OFF”... -
Page 17: Pilot Inspection, Testing And Replacement
TTW SERVICE PROCEDURE II Pilot testing, Cleaning and Replacement Pilot Inspection, Testing and Replacement Pilot Inspection, Testing and Replacement Step 1. Position gas control power switch to the Step 1. Position gas control power switch to the “OFF” position and unplug heater from wall “OFF”... -
Page 18: Pressure Switch Testing And Replacement
TTW SERVICE PROCEDURE III Pressure Switch Testing and Replacement Pressure Switch Testing WARNING 115 volt potential exposure. Use caution Step 1. Position power switch on gas control making voltage checks to avoid personal injury. 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). -
Page 19: Pressure Switch Replacement
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). -
Page 20: Blower Testing And Replacement
TTW SERVICE PROCEDURE IV Blower Testing and Replacement Blower Testing WARNING 115 volt potential exposure. Use caution when making voltage checks to avoid personal injury. Step 1. Position gas control power switch to “ON” position and adjust control to call for heat. Step 2. -
Page 21: Blower Removal
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. -
Page 22: Blower Temperature Switch Testing And Replacement
TTW SERVICE PROCEDURE V Blower Temperature Switch Testing and Replacement Blower Temperature Switch WARNING Testing. 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). - Page 23 TTW SERVICE PROCEDURE V Blower Temperature Switch Testing and Replacement Blower Temperature Switch WARNING Replacement. 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.
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Page 24: Thermal Well Testing
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... -
Page 25: Determine Water Temperature Inside Tank
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. - Page 26 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” Thermal Thermal position and Unplug Heater from power supply. Well Well Step 2.
- Page 27 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.
- Page 28 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.
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Page 29: Safety Circuit Voltage Trace
TTW SERVICE PROCEDURE VIII Safety Circuit Voltage Trace Safety Circuit Voltage WARNING Trace 115 volt potential exposure. Use caution making voltage checks to avoid personal injury. NOTE: This procedure assumes a cool tank. Remove three screws (Phillips Screw driver) from control access cover on blower and remove cover (see photo 26). -
Page 30: 115 Vac Circuit Trace
TTW SERVICE PROCEDURE IX 115 VAC Trace 115 VAC Circuit Trace WARNING 115 volt potential exposure. Use caution making voltage checks to avoid personal injury. 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 LED status LED status... -
Page 31: Dip Tube Inspection And Replacement
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”... -
Page 32: Anode Inspection And Replacement
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. - Page 33 TTW SERVICE PROCEDURE XII Flue Baffle Inspection and replacement Remove blower to gain access to Disconnect vent system from exhaust adapter. flue baffle Step 1. Position gas control power switch to the “OFF” position Blower Mounting Screws and unplug blower from wall outlet. Step 2.
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Page 34: Inner Door Gasket Replacement
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"... - Page 35 TTW SERVICE PROCEDURE XIII 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.
- Page 36 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.
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Page 37: Screenlok ® Flame Arrestor Cleaning
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. - Page 38 Glossary of Terms British Thermal Units Gallons per Minute Hertz KW/h Killo-watts per hour Light Emitting Diode National Pipe Thread Ohms Ohms of resistance Pounds per Square Inch Revolutions per Minute Temperature Cut Off Volts Alternating Current W.C. Inches of Water Column °C Degrees Centigrade °F...
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Page 39: Parts List
Parts List 1. Blower Complete 13. Heat Trap Inlet 25. Cast Iron Burner 37. Brass Drain Valve 2. Air Mixing Inlet cover 14. Inlet Dip Tube 26. Pilot Assy. (L.P.) 38. Flammable Vapor Sensor Clip 3. Pressure Switch 15. Wire Harness 27. - Page 40 Email parts@bradfordwhite.com techserv@bradfordwhite.com www.bradfordwhite.com...