Bradford-White M2TW50T BN User Manual

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The Bradford White

Through-The-WallGas 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-WallModels:

TTW Series Models:

M1TW40S*(BN,CX)(1)

M1TW40S*(BN,CX)1

M1TW50S*(BN,CX)(1)

M1TW50S*(BN,CX)1

M2TW50T*(BN,CX)(1)

M2TW50T*(BN,CX)1

M2TW65T*(BN,CX)(1)

M2TW65T*(BN,CX)1

TW450S65(B)*(N,X)

TW450S65(B)*(N,X)

TW465S65(B)*(N,X)

TW465S65(B)*(N,X)

(*) Denotes Warranty Years

(*) Denotes Warranty Years

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The Bradford White

Through-The-WallGas Water Heaters

 

 

 

 

 

 

 

 

Page

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

15I

 

 

Pilot Testing, Cleaning and Replacement

17II

 

 

 

Pressure Switch Testing and Replacement

1

 

8III

 

Blower Testing and Replacement

 

 

 

20IV

 

Blower Temperature Switch Testing and Replacement

22V

 

Gas Control & Thermal well Testing & Replacement

24VI

 

Simulated Resistive Device Testing and Replacement

28VII

 

Safety Circuit Voltage Trace

29VI

 

 

 

 

II

115VAC Circuit Trace

30IX

 

 

 

 

 

 

Dip Tube inspection and Replacement

 

31X

 

 

 

Anode Inspection and Replacement

32XI

 

 

 

Flue Baffle Inspection and Replacement

 

 

33X

II

Glossary of Terms

34--

 

 

 

 

 

 

-

Parts List

35-

 

 

 

 

 

 

 

--

Page 2

Page 2

 

 

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.

Immediately call your gas supplier from a neighbor's phone. Follow the gas supplier's instructions.

If you cannot reach your gas supplier, call the fire department.

Installation and service must be performed by a qualified installer, service agency or the gas supplier.

CAUTION

Incorrect operation of this appliance may create a hazard to life and property and will nullify the warranty.

DANGER

Do not store or use gasoline or other flammable, combustible, or corrosive vapors and liquids in the vicinity of this or any other appliance.

IMPORTANT

Before proceeding, please inspect the water heater and its components for possible damage. DO NOT install any water heater with damaged components. If damage is evident then please contact the supplier where the water heater was purchased or the manufacturer listed on the rating plate for replacement parts.

WARNING

Water heaters are heat producing appliances. To avoid damage or injury, do not store materials against the water heater or vent-airintake system. Use proper care to avoid unnecessary contact (especially by children) with the water heater andvent-airintake components. UNDER NO CIRCUMSTANCES MUST FLAMMABLE MATERIALS, SUCH AS GASOLINE OR PAINT THINNER BE USED OR STORED IN THE VICINITY OF THIS WATER HEATER,VENT-AIRINTAKE SYSTEM OR IN ANY LOCATION FROM WHICH FUMES COULD REACH THE WATER HEATER ORVENT-AIRINTAKE SYSTEM.

CAUTION

If sweat fittings are to be used DO NOT apply heat to the nipples on top of the water heater. Sweat the tubing to the adapter before fitting the adapter to the water connections. It is imperative that heat is not applied to the nipples containing a plastic liner.

WARNING

Hydrogen gas can be produced in an operating water heater that has not had water drawn from the tank for a long period of time (generally two weeks or more). Hydrogen gas is extremely flammable. To prevent the possibility of injury under these conditions, we recommend the hot water faucet to be open for several minutes at the kitchen sink before you use any electrical appliance which is connected to the hot water system. If hydrogen is present, there will be an unusual sound such as air escaping through the pipes as hot water begins to flow. Do not smoke or have open flame near the faucet at the time it is open.

WARNING

DO NOT ATTEMPT TO LIGHT ANY GAS APPLIANCE IF YOU ARE NOT CERTAIN OF THE FOLLOWING:

Liquefied petroleum gases/propane gas and natural gas have an odorant added by the gas supplier that

aids in the detection of the gas.

Most people recognize this odor as a “sulfur” or

“rotten egg” smell.

Other conditions, such as “odorant fade” can cause the odorant to diminish in intensity, or ”fade”, and not

be as readily detectable.

If you have a diminished sense of smell, or are in any way unsure of the presence of gas, immediately contact your gas supplier from a neighbor's

telephone.

Gas detectors are available. Contact your gas supplier, or plumbing professional, for more information.

WARNING

FAILURE TO INSTALL AND MAINTAIN A NEW, LISTED 3/4” X 3/4” TEMPERATURE AND PRESSURE RELIEF VALVE WILL RELEASE THE MANUFACTURER FROM ANY CLAIM THAT MIGHT RESULT FROM EXCESSIVE TEMPERATURE AND PRESSURES.

CAUTION

Turn off or disconnect the electrical power supply to the water heater before servicing. Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and dangerous operation. Verify proper operation after servicing.

Page 3

Page 3

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.

Integrated Immersion Thermostat/Gas Control Valve with LED - was developed for ease of troubleshooting by providing simple diagnostic codes to pinpoint an installation or component performance issue.

New Powerful Blower - will eliminate problems with difficult venting situations.

Quieter and Cooler Blower Operation - blower noise is significantly reduced for both interior and exterior environments. Cooler operation increases blower life by reducing bearing wear and noise.

Rugged Wiring Connections - receptacle type connections promote error free wiring.

Increased Vent Lengths - increased venting performance is achieved while maintaining Energy Factor & FHSR performance.

The TTW1, TTW2 & TW4 water heaters use a combustion system were flue gases are combined with dilution air to reduce the flue gas temperature in the blower. The diluted flue gases are evacuated to the exterior through low temperature vent materials. The gas control maintains water temperature, ignition sequence and regulates gas flow. A safety circuit consisting of a pressure switch and blower temperature switch verifies proper conditions exist for safe and reliable operation. If a situation outside of normal operating parameters exists, the gas control diagnostic LED will flash a code to positively identify an operational issue.

This service manual is designed to facilitate problem diagnosis and enhance service efficiency. To further promote quicker service times the new gas valve can be removed and replaced without draining the water heater. A special tool is required and will be provided with each gas valve kit shipped from our Service Parts department.

Please read the service manual completely before attempting service on this new series of power vent models.

Page 4

Page 4

 

 

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. Error codes are listed in the troubleshooting chart beginning on page 13 of this service manual. The troubleshooting chart will also indicate the probable cause for the error code and direct the service professional to a service procedure to properly diagnose the abnormal operation.

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.

Manometer:A

liquid “U” tube type or a digital (magna-helic)type can be used. This

 

device is used to measure gas and/or air pressure and vacuum.

Multi-Meter:

A digital type is strongly recommended. This device is used to measure

 

electrical values. The meter you select must have the capability to

 

measure volts AC, volts DC, Amps, micro-ampsand ohms.

Electronic Probes:I

n some cases, standard multi-meterprobes will damage or simply

 

not be effective to obtain certain voltage and ohm reading. It will be

 

necessary to have special electronic “pin” type multi-meterprobes.

 

Thesepr obes are available at most electronic wholesale outlets.

Thermometer:Us

ed to measure water temperature. An accurate thermometer is

 

recommended.

Water Pressure Gage:U

sed to measure water supply pressure. Also used to determine tank

 

pressure by adapting to the drain valve of the heater.

Gas Control Service Tool:BWC part number 239-45991-00.A specialized tool designed to remove

 

the gas control from gas control thermal well. Available from

 

your Bradford White parts supplier.

Various Hand Tools:Pi

pe wrench, channel locks, open end wrenchs (3/8",7/16",½"),

 

12" crescent wrench, Allen wrench set, screw drivers (common &

 

Phillips), ¼" nut driver, pliers (common & needle nose), socket set, side

 

cutters wire cutters, wire strippers, wire crimpers, torpedo level, small

 

shop vac, step ladder, and flashlight, 5 gallon pail.

Page 5

Page 5

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

PVC, CPVC or ABS

 

 

Minimum Clearance

18" from top, 24" from front, 4" sides and rear.

for Servicing

 

 

 

Water Supply Pressure

150 PSI maximum allowable working pressure. Check local codes for supply pressure

 

 

Thermal well TCO Limit

Residential 188°F (87°C), Commercial 199°F (93°C)

 

 

Residential Temperature

60°F (16°C) to 160°F (71°C) (Approximate temperatures)

Set Point Range

 

 

 

Commercial Temperature

80°F (27°C) to 180°F (82°C) (Approximate temperatures)

Set Point Range

 

Blower Temperature

Normally closed, opens @ 165°F (74°C), auto reset @ 130°F (54°C).

Switch

 

 

TTW1 Models:

 

Pressure switch

Normally open, closes on vacuum increase @ -.68,opens on vacuum decrease @-.65

TTW2 Models:

 

 

Normally open, closes on vacuum increase @ -1.28,opens on vacuum decrease @-1.25

 

 

 

TTW1

Blower

115VAC, 60Hz, 3.1 amps, 3000 RPM, 42CFM@1.5" W.C.

TTW2

 

 

115VAC, 60Hz, 3.1 amps, 3000 RPM, 68CFM@0.4" W.C.

 

 

Page 6

Page 6

 

 

Specifications

Vent Tables

Venting Specifications for:

40 Gallon

50 Gallon

2" Diameter (5.1 cm) PVC Vent Connector Lengths

Terminating

# of

 

Maximum Straight

 

Minimum Straight

 

Elbows

 

Length ft (m)

 

Length ft (m)

 

 

 

 

 

 

 

 

 

 

 

 

 

Through the Wall

1

 

45 (13.7)

 

2

(.6)

 

 

 

 

 

 

 

 

 

Through the Wall

2

 

40 (12.2)

 

2

(.6)

 

 

 

 

 

 

 

 

 

Through the Wall

3

 

35 (10.7)

 

2

(.6)

 

 

 

 

 

 

 

 

 

 

Through the Wall

4

 

30

(9.2)

 

2

(.6)

 

 

 

 

 

 

 

 

 

 

 

 

 

Through the Roof

0

 

50 (15.2)

 

7 (2.1)

 

 

 

 

 

 

 

 

Through the Roof

1

 

45 (13.7)

 

7 (2.1)

 

 

 

 

 

 

 

 

Through the Roof

2

 

40 (12.2)

 

7 (2.1)

 

 

 

 

 

 

 

 

Through the Roof

3

 

35 (10.7)

 

7 (2.1)

 

 

 

 

 

 

 

 

 

Through the Roof

4

 

30

(9.2)

 

7 (2.1)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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

1

 

115

(35.0)

 

10

(3.1)

 

 

 

 

 

 

 

 

 

 

Through the Wall

2

 

110

(33.5)

 

10

(3.1)

 

 

 

 

 

 

 

 

 

 

Through the Wall

3

 

105

(32.0)

 

10

(3.1)

 

 

 

 

 

 

 

 

 

 

Through the Wall

4

 

100

(30.5)

 

10

(3.1)

 

 

 

 

 

 

 

 

 

Through the Wall

5

 

95 (29.0)

 

10

(3.1)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Through the Roof

0

 

120

(36.6)

 

15

(4.6)

 

 

 

 

 

 

 

 

 

 

Through the Roof

1

 

115

(35.0)

 

15

(4.6)

 

 

 

 

 

 

 

 

 

 

Through the Roof

2

 

110

(33.5)

 

15

(4.6)

 

 

 

 

 

 

 

 

 

 

Through the Roof

3

 

105

(32.0)

 

15

(4.6)

 

 

 

 

 

 

 

 

 

 

Through the Roof

4

 

100

(30.5)

 

18

(5.5)

 

 

 

 

 

 

 

 

 

 

PagPage77

Specifications

Vent Tables

Venting Specifications for:

48 Gallon

65 Gallon

3" Diameter (7.6 cm) PVC Vent Connector Lengths

Terminating

# of

Maximum Straight

Minimum Straight

 

Elbows

Length ft (m)

Length ft (m)

 

 

 

 

 

 

 

 

Through the Wall

1

55 (16.8)

2 (.6)

 

 

 

 

 

 

Through the Wall

2

50 (15.2)

2 (.6)

 

 

 

 

 

 

Through the Wall

3

45 (13.7)

2 (.6)

 

 

 

 

 

 

Through the Wall

4

40 (12.2)

2 (.6)

 

 

 

 

 

 

 

 

 

 

 

Through the Roof

0

60 (18.3)

7 (2.1)

 

 

 

 

 

 

Through the Roof

1

55 (16.8)

7 (2.1)

 

 

 

 

 

 

Through the Roof

2

50 (15.2)

7 (2.1)

 

 

 

 

 

 

Through the Roof

3

45 (13.7)

7 (2.1)

 

 

 

 

 

 

4" Diameter (10.2 cm) PVC Vent Connector Lengths

Terminating

# of

Maximum Straight

Minimum Straight

 

Elbows

Length ft (m)

Length ft (m)

 

 

 

 

 

 

 

 

Through the Wall

1

85 (25.9)

10 (3.1)

 

 

 

 

 

 

Through the Wall

2

80 (24.4)

10 (3.1)

 

 

 

 

 

 

Through the Wall

3

75 (22.9)

10 (3.1)

 

 

 

 

 

 

Through the Wall

4

70 (21.3)

10 (3.1)

 

 

 

 

 

 

Through the Wall

5

65 (19.8)

12 (3.6)

 

 

 

 

 

 

 

 

 

 

 

Through the Roof

0

90 (27.4)

15 (4.6)

 

 

 

 

 

 

Through the Roof

1

85 (25.9)

15 (4.6)

 

 

 

 

 

 

Through the Roof

2

80 (24.4)

15 (4.6)

 

 

 

 

 

 

Through the Roof

3

75 (22.9)

15 (4.6)

 

 

 

 

 

 

Through the Roof

4

70 (21.3)

15 (4.6)

 

 

 

 

 

 

Page 8

Page 8

 

 

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

 

TCO Limit Lockout

Indefinite (cycle power to restart)

 

Verify Resistive Delay

Retry after 2 Minutes (repeats 5 times)

 

Simulated Resistive Load Lockout

Indefinite (cycle power to restart)

 

Hardware Error Lockout

Indefinite (self clears if fault clears for at least 15 seconds)

 

Wiring Diagram

 

 

 

Blower

Blower

 

 

Motor

 

 

Temperature

 

 

 

 

 

Switch

 

 

Pressure

 

 

Blower

Switch

 

 

 

 

 

Housing

 

 

Pilot

 

 

 

B C

A

Simulated

Resistive

Device

Thermal

Well

Page 9

Page 9

Sequence of Operation

1 Start Up.

Upon power up, the control runs a safe-startcheck with a typicalstart-updelay of1-5seconds.

2 Simulated Resistive Device Check.

To assure no outputs are energized if the “Simulated Resistive device” is out of range, the control will test the the device for proper operating range. If the device is within range the control resumes normal operation with no perceptible delay. If the device is out of range, the control LED immediately flashes 7 times with 3 second pause.

1 Thermostat calls for heat.

2

3

4

Prior to energizing blower, gas control checks safety circuit to insure the circuit is open. Normal switch positions in the safety circuit are as follows:

a)Pressure switch normally open.

b)Blower temperature switch normally closed.

If the safety circuit is closed, the control waits 4 seconds, gas control LED flashes 2 times with 3 second pause. Gas control waits 2 minutes then, blower runs for 30 seconds. This cycle repeats until safety circuit opens.

Blower energizes.

Blower pre-purgeperiod (2 seconds)

Pressure switch proves blower/vent system operation.

If the pressure switch does not close within 30 seconds, the control LED Flashes 3 times with 3 second pause. The blower runs for 30 seconds every 2 minutes trying to get the pressure switch or blower temperature switch to close. This cycle repeats as long as there is a call for heat.

5Trial for pilot ignition (90 seconds).

a)The gas control lights the pilot by activating spark igniter and gas flow to pilot burner.

b)If flame is not sensed within 90 seconds, igniter and gas flow are deactivated, blower will post purge and control LED flashes 6 times with 3 second pause.

6Main burner Ignition

After pilot flame is sensed, gas control activates main valve for main burner ignition. The gas control will ignore flame and pressure switch signals for 3 seconds allowing for main burner to stabilize.

Page 10

Page 10