Table of Contents
Advertisement
Manual 238-46238A-00B
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)
M1TW50S*F (BN,CX)
M4TW40T*F (BN,SX)
M4TW50T*F (BN,SX)
M4TW60T*F (BN,SX)
M2TW50T*F (BN,CX)
M2TW65T*F (BN,CX)
M4XRTW50T*F (BN,SX)
M4XRTW65T*F (BN,SX)
TW450S65F (B)*(N,X)
TW465S65F (B)*(N,X)
(*) Denotes Warranty Years
Save this manual for future reference
Advertisement
Table of Contents
Troubleshooting
Related Manuals for Bradford White TW Series
Summary of Contents for Bradford White TW Series
-
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) M1TW50S*F (BN,CX) M4TW40T*F (BN,SX) M4TW50T*F (BN,SX) M4TW60T*F (BN,SX) M2TW50T*F (BN,CX) M2TW65T*F (BN,CX) M4XRTW50T*F (BN,SX) M4XRTW65T*F (BN,SX) -
Page 2: Table Of Contents
Table of Contents Page TTW Service Procedure Introduction - - - How to use this manual - - - Tool required for service - - - Specifications - - - Control Timings - - - Sequence of Operation - - - Troubleshooting - - - Burner Inspection, Cleaning and Replacement... - Page 3 CAUTION WARNING: If the information in these instructions is Incorrect operation of this appliance may not followed exactly, a fire or explosion may result create a hazard to life and property and causing property damage, personal injury, or death. will nullify the warranty. FOR YOUR SAFETY DANGER Do not store or use gasoline or other...
-
Page 4: Introduction
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 and Bradford White Defender Safety System®. -
Page 5: How To Use This Manual
In some difficult to diagnose conditions, it may be necessary to isolate the heater from the vent system to determine the problem. Contact the Bradford White technical support group immediately if diagnosis can not be made using the methods described in this service manual. -
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 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) 2 (.6) Through the Wall 50 (15.2) Through the Wall...
-
Page 9: Control Timings
Specifications Control Timings Ignition State Timing Pre-purge 15 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 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
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. This chart is for water heaters with serial numbers that begin with “J” or sooner for water heaters with serial numbers that begin with “K”... - Page 14 Troubleshooting This chart is for water heaters with serial numbers that begin with “J” or sooner for water heaters with serial numbers that begin with “K” or later see page X. Service LED Status Control Status Probable Cause Procedure 1. Unstable pilot. 1.
- Page 15 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. Service LED Status Control Status Probable Cause Procedure None, control LED not on...
-
Page 16: Troubleshooting
Troubleshooting Service LED Status Control Status Probable Cause Procedure 1. Unstable pilot. 1. Page 15 2. Pilot tube blocked or restricted. Six-one flash, three Failed to light pilot. 3. Oxidation build up on pilot electrode. second pause System auto resets. 2-4. - Page 17 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.
-
Page 18: Burner Cleaning
TTW SERVICE PROCEDURE I Burner Operation Inspection, Adjustment, Cleaning and Replacement Burner Cleaning Remove Outer door. Step 1. Position gas control power switch to the “OFF” position and unplug heater from wall outlet. Step 2. Turn off gas supply to water heater. Slide inner door open from left to right. -
Page 19: Pilot Testing, Cleaning And Replacement
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 door. Step 2. Turn off gas supply to water heater. Slide inner door open from left to right. -
Page 20: Pressure Switch Testing And Replacement
TTW SERVICE PROCEDURE III Pressure Switch Testing and Replacement Pressure Switch Testing WARNING 120 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 21 TTW SERVICE PROCEDURE III Pressure Switch Testing and Replacement Pressure Switch Replacement WARNING 120 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 22: Blower Testing And Replacement
TTW SERVICE PROCEDURE IV Blower Testing and Replacement WARNING Blower Testing 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 23: 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 24: Blower Temperature Switch Testing And Replacement
TTW SERVICE PROCEDURE V Blower Temperature Switch Testing and Replacement Blower Temperature Switch WARNING 120 volt potential exposure. Use caution Testing. 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 25 TTW SERVICE PROCEDURE V Blower Temperature Switch Testing and Replacement Blower Temperature Switch WARNING Replacement. 120 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.
-
Page 26: Gas Control & Thermal Well Testing & Replacement
TTW SERVICE PROCEDURE VI Gas Control/Thermal Well Testing and Replacement Gas Control Testing See pages 29 & 30 for gas control input & output testing. Thermal Well Testing (For water heaters with serial numbers that begin with “J” or sooner.) Disconnect thermal Position gas valve power well wire harness... -
Page 27: 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 (For water heaters with serial numbers that begin with “J”... - Page 28 TTW SERVICE PROCEDURE VI Gas Control & Thermal Well Testing and Replacement Gas Control & Thermal Well Removal From Water Heater (For water heaters with serial numbers that begin with “J” or sooner.) Gas Control Thermal Step 1. Position gas valve power switch to the “OFF” Well position and Unplug Heater from power supply.
- Page 29 TTW SERVICE PROCEDURE VI Gas Control & Thermal Well Testing and Replacement Gas Control Assembly to Thermal Well (For water heaters with serial numbers that begin with “J” or sooner.) 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 30: Simulated Resistive Device Testing And Replacement
TTW SERVICE PROCEDURE VII Simulated Resistive Device Testing Simulated Resistive Device Testing Step 1. Position power switch on gas control to the “OFF” position. Step 2. Disconnect simulated resistive device from gas control. Step 3. Using a multi-meter set to the ohms setting check resistance of simulated resistive device. -
Page 31: Safety Circuit Voltage Trace
TTW SERVICE PROCEDURE VIII Safety Circuit Voltage Trace Safety Circuit Voltage WARNING Trace 120 volt potential exposure. Use caution making voltage checks to avoid personal injury. NOTE: This procedure assumes a cool tank. Step 2. Remove three screws (Phillips Screw driver) from control access cover on blower and remove cover (see photo 26). -
Page 32: 115Vac Circuit Trace
TTW SERVICE PROCEDURE IX 120 VAC Trace WARNING 120 VAC Circuit Trace 120 volt potential exposure. Use caution making voltage checks to avoid personal injury. Step 1. Verify 120VAC 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 33: 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 34: 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 35: Flue Baffle Inspection And Replacement
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. -
Page 36: Glossary Of Terms
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... - Page 37 NOTES...
- Page 38 NOTES...
- Page 39 NOTES...