Bradford-White PE2XR504T'F(BN,SX) User Manual

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P rammable Efficiency

Ga

r Heate

S ICE

MANUAL

SUPPLEMENT

T eshooting Guide a structions for Service

(To be performed ONLY by qua ce providers)

M

Covered

b

 

PE4403

SX)

PE440T

 

PE4503

 

PE2XR5

 

(*) Denotes Warra y Years

M

l 238-48494

Save this manual for future reference

Table of Contents

Section

Page

Introduction ______________________________________________5 How to Use this Manual _____________________________________6 Tools Required for Service ___________________________________6 Specifications _____________________________________________7 Sequence of Operation______________________________________9

Power Up Sequence Normal Heating Sequence Abnormal Operation

Troubleshooting __________________________________________ 13 Burner Maintenance _______________________________________ 17

Burner Inspection

Burner Cleaning Procedure

Pilot Maintenance _________________________________________ 19 Pilot Inspection, Testing and Replacement

Thermal Well Testing ______________________________________ 21 Determine Water Temperature Inside Tank_____________________ 22 Component Disassembly ___________________________________ 24 Gas Control Removal ______________________________________ 25 Gas Control Assembly _____________________________________ 26 Flammable Vapor Sensor Testing_____________________________ 27 120 VAC Circuit Trace _____________________________________ 28 Relay Replacement________________________________________ 28 Common Terms __________________________________________ 30 Notes __________________________________________________ 30 Parts List _______________________________________________ 31

Page 2

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.

What to do if you smell gas:

xDo not try to light any appliance

xDo not touch any electrical switch; do not use any phone in your building

xImmediately call your gas supplier from a neighbor’s phone. Follow the gas supplier’s instructions.

xIf 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.

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

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

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.

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.

NOTICE

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.

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.

Page 3

3

WARNING

Water heaters are heat producing appliances. To avoid damage or injury, do not store materials against the water heater or any of its components. Use proper care to avoid unnecessary contact, especially by children, with the water heater and its components. Under no circumstances must flammable materials, such as gasoline or paint thinner be used or stored in the vicinity of this water heater or in any location in which the fumes could reach the water heater.

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 a 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.

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.

Do not operate the water heater or its accessories without the Accessory Module cover in place. Do not operate the water heater or Setback Control without the Setback Control Junction Box Assembly cover in place.

Do not operate the water heater, Accessory Module, and Setback Control with jumpered or absent controls or safety devices.

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

All electrical wiring must be installed and grounded in accordance with local codes, or in the absence of local codes, the National Electrical Code, ANSI/NFPA 70 and/or CSA C22 Electrical Code.

Page 4

4

Introduction

The Bradford White DEFENDER Safety System®

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 will instruct service professionals on the function, proper diagnosis, and repair of water heaters employing the Bradford White DEFENDER Safety System.

Introduction

The new Bradford White Programmable Efficiency water heaters are designed to provide reliable performance with enhanced standard features. New design features include reliable spark-to-pilotignition system, enhanced diagnostics, simplified servicing, and the Bradford White Defender Safety System.

Spark-to-Pilot Ignition System - employing thespark-to-pilotignition system promotes reliable and consistent pilot and main burner ignitions to provide hot water on demand.

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

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

The gas control maintains water temperature, ignition sequence, and regulates gas flow. 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 gas control can be removed and replaced without draining the water heater. A special tool is required and will be provided with each gas control kit shipped from your Bradford White wholesale distributor.

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

How the DEFENDER Safety System Works

During normal operation, air for combustion is drawn into the water heater through the openings in the jacket. This air travels down and around the combustion chamber and enters through holes in the very bottom of the corrosion resistant combustion chamber. The air then travels up through the flame arrestor louvers, where the velocity of the air is increased and its direction altered. The air then mixes in a normal manner with supplied gas and is efficiently combusted, producing very low NOx emissions.

In the unlikely event trace amounts of flammable vapors are present in the air flowing into the combustion chamber, the vapors are harmlessly ignited by the burner. If flammable vapors are in sufficient quantity to prevent normal combustion, the flammable vapor sensor recognizes this and shuts down the pilot and main burner. Should the flammable vapors continue to burn, the flame arrestor prevents the flames from traveling backwards and igniting vapors outside of the combustion chamber. In addition, the resettable thermal switch will open and shut down the pilot and main burner.

Page 5

5

How to Use this Manual

How to Use this Manual

This manual serves as a supplement to the Defender Atmospheric service manual, p/n 238-44943-00.Please refer to the Defender Atmospheric service manual for all features on this water heater that are consistent with a Defender (standard) Atmospheric water heater.

It is intended for this manual to be used by qualified service personnel for the primary purpose of troubleshooting and repair of the Bradford White Programmable Efficiency 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. Diagnostic 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 diagnostic code and direct the service professional to a service procedure to properly diagnose the abnormal operation.

Contact the Bradford White technical support group immediately if diagnosis cannot be made using the methods described in this service manual.

Tools Required for Service

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: In some cases, standardmulti-meterprobes will damage or simply not be effective to obtain certain voltage and ohm reading. It will be necessary to have special electronic “pin” typemulti-meterprobes. These probes are available at most electronic wholesale outlets.

Thermometer: Used to measure water temperature. An accurate thermometer is recommended.

Water Pressure Gage: Used 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 p/n239-45991-00.A specialized tool designed to remove the gas control from the thermal well. Available from your Bradford White parts supplier and is supplied with replacement gas controls.

Various Hand Tools: Pipe wrench, channel locks, open end wrenches (3/8", 7/16", 1/2"), 12" crescent wrench, Allen wrench set, screw drivers (common & Phillips), 1/4" nut driver, pliers (common & needle nose), socket set, side cutters, wire cutters, wire strippers, wire crimpers, torpedo level, small shop vac, step ladder, flashlight, and 5 gallon pail.

Page 6

6

Specifications

 

Specifications

 

 

Power Supply

Dedicated 120VAC, 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” w.c. minimum for Natural Gas; 11” w.c. for Propane; 14”

w.c. maximum for Natural Gas / Propane

 

 

 

Approved Vent Materials

Single or Double Wall Metal Vent Pipe

 

 

Minimum Clearance for

18” from top; 24” from front; 4” from sides and rear

Servicing

 

 

 

Water Supply Pressure

150 psi maximum allowable working pressure; check local

codes for supply pressure

 

 

 

ECO Limit

188°F (87°C)

 

 

Temperature Setpoint Range

60°F (16°C) to 160°F (71°C); approximate temperatures

 

 

Page 7

7

Specifications

Control Timings

Ignition State

Timing

 

 

Energize Relay and Verify (Closed Circuit)

15 seconds

 

 

Trial for Ignition

90 seconds

 

 

Flame Stabilization Period

3 seconds

 

 

Re-energizeRelay and Verify

15 seconds

 

 

Flame Failure Response Time

1.5 seconds (2 second maximum; 1 second

minimum)

 

 

 

De-energizeRelay and Verify (Open Circuit)

15 seconds

 

 

Relay Fault (failed open/close)

Retry after 2 minutes

 

 

Soft Lockout

Retry after 5 minutes

 

 

ECO Limit Lockout

Indefinite (See page 11 to reset)

 

 

Verify Resistive Delay

Retry after 2 minutes (repeats 5 times)

 

 

Simulated Resistive Load Lockout

Indefinite (cycle power to reset)

 

 

Hardware Error Lockout

Indefinite (self clears if fault clears for at least 15

seconds)

 

 

 

 

Wiring Diagram

PILOT

GAS VALVE

W

Honeywell

C

 

E

R

Y

 

 

T

V

 

 

O

 

 

 

B

 

 

 

H

 

A

 

 

 

 

 

 

 

 

 

 

 

 

 

HOT

 

 

 

 

 

 

 

L

O

W

BL BK

W

BK R

FLAMMABLE

VAPOR SENSOR

BK

R BK

 

BK

BK

G W

Y

BK

 

WATER

 

 

 

 

 

 

 

TEMPERATURE

 

 

 

 

SENSOR

BK

 

 

 

 

 

 

RE-SETTABLE

BK

 

 

 

 

 

THERMAL SWITCH

W

 

 

 

 

 

G

 

 

 

 

 

 

POWER CORD

 

 

 

 

 

 

 

 

 

 

 

ACCESSORY

 

 

 

 

 

 

MODULE

 

 

W

BK

 

 

 

W

G

W

BK

 

BK

 

 

 

RBK

 

 

 

 

 

G

 

 

 

W

W

 

 

 

 

 

W

 

 

 

PLUG-IN

 

 

 

BL

 

 

TRANSFORMER

 

R Y

 

AC AC

 

 

SETBACK CONTROL

W

BK

 

 

 

JUNCTION BOX

 

 

 

Page 8

SETBACK CONTROL

8

Sequence of Operation

Note: The Sequence of Operation section is in addition to the Defender Atmospheric Service Manual, p/n 238-44943-00.

Power Up Sequence

1.Start-up: Upon power up, the gas control runs a safe start check with a typical delay of 5 seconds.

2.Flammable Vapor Verification: The gas control verifies that the Flammable Vapor Sensor is in the proper operating range prior to energizing any components. If the sensor is within the proper range, the gas control resumes normal operation. If the Flammable Vapor Sensor is out of range, the gas control LED immediately flashes 7 times with a 3 second pause.

Normal Heating Sequence

1.Thermostat Calls for Heat: Prior to energizing the relay, the gas control verifies the safety circuit to see if it is in the correct state. If the safety circuit is closed, the gas control LED flashes 2 times with a 3 second pause. The gas control waits 2 minutes. Then, the control cuts power to the relay. This cycle repeats until the safety circuit opens.

2.Relay Energized

3.Safety Circuit Check: If the safety circuit does not close within 30 seconds, the gas control LED flashes 3 times with a 3 second pause. The relay is powered for a maximum of 30 seconds every 2 minutes trying to close the safety circuit. This cycle repeats as long as there is a call for heat.

4.Hold Period (15 seconds)

5.Trial for Pilot Ignition (90 seconds): The gas control lights the pilot by activating the spark igniter and gas flow to the pilot burner. If flame is not sensed within 90 seconds, the spark igniter and gas flow are deactivated. The relay will remain powered, and the gas control LED flashes 6 times with a 3 second pause.

6.Main Burner Ignition: After pilot flame is sensed, the gas control activates the main valve for main burner ignition. The gas control will ignore flame signals for 3 seconds to allow for the main burner to stabilize.

Page 9

9

Sequence of Operation

Normal Heating Sequence (cont’d)

7.Steady State Operation: During steady state operation, the gas control monitors:

Thermostat Temperature Sensor: When the setpoint temperature is satisfied, the gas control is shutdown, and power is removed from the relay. The gas control LED flashes a short flash once every 4 seconds (Idle status code).

Relay Status: If the relay is altered during a call for heat, the pilot and main valves are shutdown. The relay is powered attempting to close the safety circuit. The gas control LED flashes 3 times with a 3 second pause.

Flame Sensor: If flame is lost, the pilot and main valves are shutdown. The relay is powered. The gas control attempts to re-lightthe pilot 4 times. If unsuccessful, power is removed from the relay, and the gas control proceeds to a 5 minute lockout. The gas controlre-attemptsto light the pilot starting at Normal Heating Sequence #2.

8.Thermostat Satisfies: Gas control LED flashes once every 4 seconds.

9.Burner Off

10.Relay De-energized(15 seconds)

Abnormal Operation

1.Flammable Vapor Sensor Fault:

A)If the resistance is greater than 70,000 ohms: The gas control immediately turns off all outputs. The gas control waits and monitors resistance for 30 seconds. If the resistance is greater than 65,000 ohms after 30 seconds, the gas control proceeds to verify resistive delay for 2 minutes and flashes 7 times then 1 time with a three second pause. This process is repeated 5 times until the control either returns to normal operation or proceeds to flammable vapor lockout.

B)If the resistance is below 3000 ohms: The gas control immediately turns off all outputs and proceeds to flash 8 times then 1 time with a three second pause. The error self clears if the resistance returns to normal range for at least 15 seconds.

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