Bradford-White PDX50S60F(B User Manual

Size:
1.74 Mb
Download

Bradford White

PDX Series

Powered Direct Vent Gas Water Heaters

SERVICE

MANUAL

Troubleshooting Guide and Instructions for Service

(To be performed ONLY by qualified service providers)

For Bradford White

PDX Series Models:

PDX250T6*F(BN,CX)

PDX265T6*F(BN,CX)

PDX275T6*F(BN,CX)

PDX50S60F(B,C)*(N,X)

PDX65S65F(B,C)*(N,X)

PDX75S70F(B,C)*(N,X)

(*) Denotes Warranty Years

Manual 46925A

Save this manual for future reference

 

 

Bradford White

PDX Series

Powered Direct Vent Gas Water Heaters

Table of Contents

 

 

Page

TTW Service Procedure

Introduction

 

4

 

- - -

How to use this manual

5

- - -

Tool required for service

5

- - -

Specifications

6

- - -

Control Timings

8

- - -

Sequence of Operation

9

- - -

Troubleshooting

12

- - -

Burner Inspection, Cleaning and Replacement

14

 

I

Pilot Testing, Cleaning and Replacement

16

 

II

Pressure Switch Testing and Replacement

17

 

III

Blower Testing and Replacement

21

 

IV

Blower Temperature Switch Testing and Replacement

23

 

V

Gas Control & Thermal well Testing & Replacement

25

 

VI

Flammable Vapor Sensor Testing & Replacement

29

 

VII

Safety Circuit Voltage Trace

30

 

VIII

115VAC Circuit Trace

31

 

IX

Dip Tube inspection and Replacement

32

 

X

Anode Inspection and Replacement

33

 

XI

Flue Baffle Inspection and Replacement

34

 

XII

Inner Door Removal, Inspection & Replacement

35

 

XIII

Glossary of Terms

38

- - -

Parts List

39

- - -

Page 2

2

PDX Series

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

3

PDX Series

Introduction

The new Bradford White PDX2 and PDX 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 quieter operation, additional vent lengths and certified FVIR technology.

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 PDX2 and PDX water heaters use a combustion system were flue gases are combined with dilution air to reduce the flue gas temperature in the blower, combustion air and dilution air are drawn from outside the building. 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.

How the Safety System Works

During normal operation, air for combustion is drawn into the water heater though the vent pipe from outside your building. The air travels into the closed combustion chamber. The air then mixes with in a normal manner with supplied gas and its efficiently combusted, producing very low NOx emissions.

In the unlikely event trace amounts of flammable vapors are present in the area surrounding the water heater, the sealed combustion system prevents the flammable vapors from reaching the ignition source. In addition the flammable vapors sensor will stop the water heater from operating if a significant amount of flammable vapors are present.

Page 4

4

PDX Series

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 12 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.

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, 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.

 

 

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 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:

Pipe 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

5

PDX Series

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

 

 

Exhaust-Normallyopen, closes on vacuum increase @-1.30.

Pressure switch

Intake-Normallyclosed, opens on vacuum increase @-1.15.

 

 

 

Blower

115VAC, 60Hz, 3.1 amps.

 

 

Page 6

6

Vent Tables

PDX Series

Specifications

Venting Specifications for:

48 Gallon

65 Gallon

75 Gallon

This water heater is approved for installation with the following PVC, CPVC or ABS Schedule 40 venting material.

The maximum and minimum vent lengths listed on this label are for the exhaust portion of the vent. The intake portion of the vent must be equal to or less than the length of the exhaust.

3" Diameter (7.6 cm) PVC Vent Connector Lengths

 

# of

 

Maximum 48, 65 gal.

 

 

Maximum 75 gal.

 

Terminating

 

Maximum

 

Minimum

 

Maximum

 

Minimum

 

Elbows

 

 

 

 

 

 

 

Length ft (m)

 

Length ft (m)

 

Length ft (m)

 

Length ft (m)

 

 

1

 

55 (16.8)

 

2

(.6)

 

45

(13.7)

 

2

(.6)

 

Through the Wall

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Through the Wall

2

 

50 (15.2)

 

2

(.6)

 

40

(12.2)

 

2

(.6)

 

Through the Wall

3

 

45 (13.7)

 

2

(.6)

 

35

(10.7)

 

2

(.6)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Through the Wall

4

 

40 (12.2)

 

2

(.6)

 

30 (9.1)

 

2

(.6)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Through the Roof

0

 

60 (18.3)

 

7 (2.1)

 

50

(15.2)

 

7 (2.1)

 

 

 

 

 

 

 

 

 

 

 

 

 

Through the Roof

1

 

55 (16.8)

 

7 (2.1)

 

45

(13.7)

 

7 (2.1)

 

Through the Roof

2

 

50 (15.2)

 

7 (2.1)

 

40

(12.2)

 

7 (2.1)

 

 

 

 

 

 

 

 

 

 

 

 

 

Through the Roof

3

 

45 (13.7)

 

7 (2.1)

 

35

(10.7)

 

7 (2.1)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4" Diameter (10.2 cm) PVC Vent Connector Lengths

 

 

 

 

 

# of

 

Maximum 48, 65 gal.

 

 

Maximum 75 gal.

 

 

 

 

 

 

Terminating

 

Maximum

 

Minimum

 

Maximum

 

Minimum

 

Elbows

 

 

 

 

 

 

 

Length ft (m)

 

Length ft (m)

 

Length ft (m)

 

Length ft (m)

 

 

1

 

95 (29.0)

 

10

(3.1)

 

85

(25.9)

 

10

(3.1)

 

Through the Wall

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Through the Wall

2

 

90 (27.4)

 

10

(3.1)

 

80

(24.4)

 

10

(3.1)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Through the Wall

3

 

85 (25.9)

 

10

(3.1)

 

75

(22.9)

 

10

(3.1)

 

Through the Wall

4

 

80 (24.4)

 

10

(3.1)

 

70

(21.3)

 

10

(3.1)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Through the Wall

5

 

75 (22.9)

 

12

(3.6)

 

65

(19.8)

 

12

(3.6)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Through the Roof

0

 

100 (30.5)

 

15

(4.6)

 

90

(27.4)

 

15

(4.6)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Through the Roof

1

 

95 (29.0)

 

15

(4.6)

 

85

(25.9)

 

15

(4.6)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Through the Roof

2

 

90 (27.4)

 

15

(4.6)

 

80

(24.4)

 

15

(4.6)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Through the Roof

3

 

85 (25.9)

 

15

(4.6)

 

75

(22.9)

 

15

(4.6)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Through the Roof

4

 

80 (24.4)

 

15

(4.6)

 

70

(21.3)

 

15

(4.6)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Page 7

7

PDX Series

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

Page 8

8

PDX Series

Sequence of Operation

Power up Sequence

1

2

Start Up.

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

Flammable Vapor Check.

To assure no outputs are energized if the “Flammable Vapor Sensor” is out of range, the control will test the 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. If the “Flammable Vapor Sensor” is out of range, the control LED immediately flashes 7 times with 3 second pause.

Normal Heating Sequence

1 Thermostat calls for heat.

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)Exhaust pressure switch normally open.

b)Blower temperature switch normally closed.

c)Inlet pressure 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.

2Blower energizes.

3Blower pre-purgeperiod (2 seconds)

4Exhaust pressure switch proves blower/vent system operation.

a)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.

b)The normally closed inlet pressure switch allows the system to work as long as the inlet air is not blocked.

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 9

9

PDX Series

Sequence of Operation

Normal Heating Sequence (cont.)

Steady state operation.

7During 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. The control LED Flashes3 times with 3 second pause.

Flame Sense- If flame is lost, pilot & main valve are shut down, blower runs for 15 seconds. Control attempts tore-lightpilot 4 times. If unsuccessful, Blower is shut down and control proceeds to 5 minute lockout. Controlre-attemptsto light pilot starting at normal heating sequence #2.

8Thermostat satisfies.

9Burner off.

10 Blower post purge (15 seconds).

Abnormal Operation

1. Simulated Resistive Device Fault:

a)If the Flammable Vapor Sensor resistance is greater than 70,000 Ohms - the gas control immediately turns off all outputs. Control waits and monitors resistance for 30 seconds. If the resistance is greater than 70,000 ohms after 30 seconds, the gas control proceeds to verify resistive delay for 2 minutes and flashes 7 times with a three second pause. This process is repeated 5 times until the control either returns to normal operation or proceeds to a lockout mode flashing 7 times with a 3 second pause.

b)If the Flammable Vapor Sensor resistance is below 3000 ohms - The gas control immediately turns off all outputs and proceeds to flash 8 times then once with three second pause. The error self clears if the resistance returns to normal range for at least 15 seconds.

2. Temperature Sensor Fault:

a)Temperature sensor detected open circuit - The gas control Immediately turns off all outputs and proceeds to flash8 times then three times with three second pause. The error self clears if the fault clears for at least 15 seconds.

b)Temperature sensors not reading the same temperature within ±5.5 °F - The gas control Immediately turns off all outputs and proceeds to flash 8 times then three times with three second pause. The error self clears if the fault clears for at least 15 seconds.

c)Water temperature in excess of TCO (Temperature Cut Off) limit - The gas control immediately turns off pilot & main valve and proceeds to flash 4 times with 3 second pause. Blower continues to run until gas control is reset. Power needs to be cycled to remove gas control from TCO lockout.

Page 10

10