Bradford White PDX Series User manual

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Manual 238-49770-00A
SERVICE
MANUAL
Troubleshooting Guide
and Instructions for Service
(To be performed ONLY by
qualified service providers)
Models Covered
by This Manual:
PDX Series Models:
PDX140S*F(BN,SX,CX)
PDX150S*F(BN,SX,CX)
PDX440S*F(BN,SX)
PDX450S*F(BN,SX)
PDX250T*F(BN,SX,CX)
PDX265T*F(BN,SX,CX)
PDX275T*F(BN,SX,CX)
PDX50S60F(B,S,C)*(N,X)
PDX65S65F(B,S,C)*(N,X)
PDX75S70F(B,S,C)*(N,X)
(*) Denotes Warranty Years
Powered Direct Vent Gas Water Heaters
PDX Series

Table of Contents
Page PDX 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 15 I
Pilot Testing, Cleaning and Replacement 17 II
Pressure Switch Testing and Replacement 18 III
Blower Testing and Replacement 20 IV
Blower Temperature Switch Testing and Replacement 22 V
Gas Control & Thermal well Testing & Replacement 24 VI
Flammable Vapor Sensor Testing & Replacement 28 VII
Safety Circuit Voltage Trace 29 VIII
115VAC Circuit Trace 30 IX
Dip Tube inspection and Replacement 31 X
Anode Inspection and Replacement 32 XI
Flue Baffle Inspection and Replacement 33 XII
Inner Door Removal, Inspection & Replacement 34 XIII
Glossary of Terms 38 - - -
Parts List 39 - - -
Page 2
2

WARNING: Iftheinformation inthese instructions is
not followed exactly, afireor explosion may result
causing property damage, personal injury, or death.
WHATTO DO IF YOU SMELL GAS
Donot try to lightany appliance.
Donot touch any electrical switch; donot use any
phone inyour building.
Immediately call your gas supplier from aneighbor'sphone.
Follow thegas supplier'sinstructions.
Ifyou cannot reach your gas supplier, call thefire
department.
Installation and servicemust be performed by aqualified
installer, serviceagency or thegas supplier.
FOR YOUR SAFETY
Donot storeor use gasoline or other flammable,
combustible, or corrosivevaporsand liquidsinthe
vicinity of thisor any other appliance.
CAUTION
Incorrectoperation of thisappliancemay
create ahazard to life and property and
will nullify thewarranty.
DANGER
Donot storeor use gasoline or other
flammable, combustible, or corrosive
vaporsand liquidsinthevicinity of thisor
any other appliance.
IMPORTANT
Beforeproceeding, please inspectthe
water heater and its components for
possible damage. DO NOTinstall any
water heater with damaged components.
Ifdamage isevident then please contact
thesupplier wherethewater heater was
purchased or themanufacturer listed on
therating plate for replacement parts.
WARNING
Water heatersareheat producing appliances. To avoid
damage or injury, donot storematerials against the
water heater or vent-air intakesystem. Use proper care
to avoid unnecessary contact(especially by children) with
thewater heater and vent-air intakecomponents. UNDER
NO CIRCUMSTANCES MUSTFLAMMABLE MATERIALS,
SUCH AS GASOLINE OR PAINTTHINNER BE USED OR
STORED IN THE VICINITY OF THIS WATER HEATER, VENT-
AIR INTAKE SYSTEM OR IN ANY LOCATION FROM WHICH
FUMES COULD REACH THE WATER HEATER OR VENT-AIR
INTAKE SYSTEM.
WARNING
DO NOTATTEMPT TO LIGHTANY GAS APPLIANCE IF YOU ARE
NOTCERTAIN OF THE FOLLOWING:
Liquefied petroleum gases/propane gas and natural gas
havean odorant added by thegas supplier that aidsin
thedetection of thegas.
Most people recognizethisodor as a“sulfur” or “rotten
egg” smell.
Other conditions, such as “odorant fade” can cause the
odorant to diminish inintensity, or ”fade”, and not be as
readily detectable.
Ifyou haveadiminished sense of smell, or areinany way
unsureof thepresenceof gas, immediately contactyour
gas supplier from aneighbor'stelephone.
Gas detectorsareavailable. Contactyour gas supplier, or
plumbing professional, for moreinformation.
CAUTION
Ifsweat fittings areto be used DO NOTapply heat to the
nipples on top of thewater heater. Sweat thetubing to
theadapter beforefitting theadapter to thewater
connections. Itisimperativethat heat isnot applied to
thenipples containing aplastic liner. 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
MIGHTRESULTFROM EXCESSIVE TEMPERATURE AND
PRESSURES.
WARNING
Hydrogen gas can be produced inan operating water
heater that has not had water drawnfrom thetank for a
long period of time(generally twoweeksor more).
Hydrogen gas isextremely flammable.To prevent the
possibility of injury under these conditions, we
recommend thehot water faucet to be open for several
minutes at thekitchen sink beforeyou use any electrical
appliancewhich isconnected to thehot water system. If
hydrogen ispresent, therewill be an unusual sound such
as air escaping through thepipes as hot water begins to
flow. Donot smokeor haveopen flamenear thefaucet
at thetimeitisopen.
CAUTION
Turnoff or disconnecttheelectrical power supply to the
water heater beforeservicing. Label all wires prior to
disconnection when servicing controls. Wiring errorscan
cause improper and dangerousoperation. Verify proper
operation after servicing.
Page 3
PDX Series
3

Page4
Introduction
The new Bradford White PDX1, PDX2 and PDX4 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 PDX1, PDX2, and PDX4 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 non metallic 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.
PDX Series
4

Tools Required for Service
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 PDX 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.
Page5
Manometer: A liquid “U” tube type or adigital (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-amps and ohms.
Electronic Probes:Insome cases, standard multi-meter probes will damageor simply
not be effective to obtain certain voltageand ohm reading.Itwill be
necessary to have special electronic “pin” type multi-meter probes.
These probes are available at most electronic wholesale outlets.
Thermometer:Used to measure water temperature. Anaccurate 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:BWCpart 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.
How to Use This Manual
PDX Series
5

Specifications
Thermal well TCO Limit Residential 188°F(87°C),Commercial 199°F(93°C)
Residential Temperature
Set Point Range 60°F(16°C) to 160°F(71°C) (Approximate temperatures)
Blower Temperature Switch Normally closed, opens @ 155°F(68°C),auto reset @ 128°F(54°C).
Blower 115VAC, 60Hz,3.1amps.
Pressure switch
Standard Altitude-Normallyopen, closes at differential pressure of -.80.
High Altitude-Normallyopen, closes at differential pressure of -.73.
Power supply Dedicated 115VAC, 60 Hz,15A
Approved Gas Type Natural or Propane. Unit must match gas type supplied.
Venting System Power direct vent through the wall or vertical through the roof
Approved Vent Materials PVC, CPVCor ABS
Gas Supply Pipe Minimum 1/2" NPT (schedule 40black iron pipe recommended)
Minimum Clearance
for Servicing 18" from top, 24"from front, 4"sides and rear.
Water Supply Pressure 150 PSI maximum allowable working pressure. Check local codes for supply pressure
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.)
Commercial Temperature
Set Point Range 80°F (27°C) to 180°F (82°C) (Approximate temperatures)
Page 6
PDX Series
6

Specifications
VentingSpecificationsfor:
48 Gallon
65 Gallon
75 Gallon
This water heater is approved for installation withthe 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 lengthof the
exhaust.
Through the Wall
Terminating # of
Elbows Maximum
Length ft (m)
Minimum
Length ft (m)
3" Diameter (7.6 cm) PVC Vent Connector Lengths
155 (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 Wall
Terminating # of
Elbows Maximum
Length ft (m)
Minimum
Length ft (m)
4" Diameter (10.2 cm) PVC Vent Connector Lengths
1 95(29.0)10 (3.1)
Through the Wall 2 90 (27.4)10 (3.1)
Through the Wall 3 85 (25.9)10 (3.1)
Through the Wall 4 80 (24.4)10 (3.1)
Through the Roof 0 60 (18.3) 7 (2.1)
Through the Roof 155 (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)
Through the Roof 0 100 (30.5) 15(4.6)
Through the Roof 195(29.0)15(4.6)
Through the Roof 2 90 (27.4)15(4.6)
Through the Roof 3 85 (25.9)15(4.6)
Through the Wall 5 75 (22.9)12(3.6)
Through the Roof 4 80 (24.4)15(4.6)
Vent Tables
Page 7
PDX Series
Maximum
Length ft (m)
Minimum
Length ft (m)
45(13.7) 2(.6)
40 (12.2)2 (.6)
35 (10.7)2 (.6)
30 (9.1)2 (.6)
50 (15.2)7 (2.1)
45(13.7) 7 (2.1)
40 (12.2) 7 (2.1)
35 (10.7) 7 (2.1)
Maximum 75gal.Maximum 48,65gal.
Maximum 75gal.Maximum 48,65gal.
Maximum
Length ft (m)
Minimum
Length ft (m)
85(25.9)10 (3.1)
80 (24.4) 10 (3.1)
75(22.9)10 (3.1)
70 (21.3) 10 (3.1)
90 (27.4) 15(4.6)
85(25.9)15(4.6)
80 (24.4) 15(4.6)
75(22.9)15(4.6)
65(19.8)12(3.6)
70 (21.3) 15(4.6)
7

Specifications
PartII-Venting Specifications for:
40 Gallon
50 Gallon
Through the Wall
Terminating
#of
Elbows
(excl. vent
term.)
Maximum
straight
Length ft (m)
VENTCONNECTOR LENGTHS FOR 2" (5.1 cm) DIAMETER VENT PIPE
130 (9.1)
Through the Wall 2 25 (7.6)
Through the Wall 3
Through the Wall 4 15(4.6)
Through the Roof 035 (9.1)
Through the Roof 130 (9.1)
Through the Roof 2 25 (7.6)
Through the Roof 3 20 (6.1)
Vent Tables
Page 8
PDX Series
Minimum
straight
Length ft (m)
2 (.6)
2 (.6)
2 (.6)
2 (.6)
7(2.1)
7(2.1)
7(2.1)
7(2.1)
IMPORTANT
The minimum equivalent length for the exhaust portion of the vent is7feet. The maximum equivalent vent length for the exhaust is35 feet
for 2" diameter pipeand 85 feet for 3" diameter pipe. The intake portion of the vent must be equal to or less than the vent length of the
exhaust. The tables below areprovided for your quickreference, some installations may requireagreater number of elbows. When
calculating equivalent vent length, one 90°elbow isequivalent to 5feet.
20 (6.1)
Through the Wall
Terminating
#of
Elbows
(excl. vent
term.)
Maximum
straight
Length ft (m)
VENTCONNECTOR LENGTHS FOR 3" (7.6 cm) DIAMETER VENT PIPE
180 (24.4)
Through the Wall 2 75 (22.9)
Through the Wall 3
Through the Wall 4 65(19.8)
Through the Roof 5 60 (18.3)
Through the Roof 085 (29.9)
Through the Roof 180 (24.4)
Through the Roof 2 75 (22.9)
Maximum
straight
Length ft (m)
10 (3.1)
10 (3.1)
10 (3.1)
10 (3.1)
10 (3.1)
15(4.6)
15(4.6)
15(4.6)
70 (21.3)
Through the Roof
Through the Roof
3 70 (22.3)
65(19.8)4
15(4.6)
15(4.6)
8

Control Timings
IgnitionState Timing
Pre-purge 15 Seconds
Trial for Ignition 90 Seconds
Flame Stabilization Period3 Seconds
Inter-purge 15 Seconds
Flame Failure Response Time 1.5Seconds(2second.Maximum;1secondminimum.)
Post-purge 15 Seconds
PS Fault Delay(failedopen/close)Retryafter 2Minutes
Soft Lockout Retryafter 5Minutes
TCOLimit Lockout Indefinite (cycle power to restart)
SimulatedResistiveLoadLockout Indefinite (cycle power to restart)
Hardware Error Lockout Indefinite (self clears if fault clears for at least 15 seconds)
VerifyResistiveDelayRetryafter 2Minutes (repeats 5times)
Specifications
Page 9
PDX Series
9

Sequence of Operation
Thermostat calls for heat.
Prior to energizing blower,gas control checks safetycircuit to insure the circuit is open. Normal switch positions
in the safetycircuit are as follows:
a) Exhaust pressure switch normallyopen.
b) Blower temperature switch normallyclosed.
If the safetycircuit is closed, the control waits 4 seconds,gas control LED flashes 2times with 3 second pause.
Gas control waits 2minutes then, blower runs for 30seconds. This cycle repeats until safetycircuit opens.
1Start Up.
Uponpower up, the control runs a safe-start check with a typical start-up delayof 1-5 seconds.
2Flammable Vapor Check.
To assure no outputs are energizedif 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 operationwith no perceptible delay. If the “Flammable Vapor Sensor” is out of range,the
control LED immediatelyflashes 7 times with 3 second pause.
1
2Blower energizes.
3
Differential pressure switch proves blower/vent system operation.
a) If the pressure switch does not close within 30seconds,the control LED Flashes 3times with 3 second pause.
The blower runs for 30seconds every2minutes trying to get the pressure switch or blower temperature
switch to close. This cycle repeats as long as there is a call for heat.
4
Blower pre-purge period (15 seconds)
5Trial for pilot ignition(90seconds).
a) The gas control lights the pilot by activating spark igniter and gas flowto pilot burner.
b) If flame is not sensedwithin 90seconds,igniter and gas floware deactivated, blower will post purge and
control LED flashes 6times 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
PDX Series
10

Steady state operation.
DuringSteady 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 flashonce every 4 seconds (idle) status
code.
Pressure switch / Blower temperature switch-Ifeither switch opens,pilot valve and main valve is shut
down. The blower continues to run for 30seconds attemptingto close the circuit. The control LED Flashes
3times with3 second pause.
Flame Sense-Ifflame is lost,pilot & main valve are shut down,blower runs for 15 seconds. Control attempts
to re-light pilot 4 times. Ifunsuccessful,Blower is shut down and control proceeds to 5 minute lockout. Control
re-attempts to light pilot startingat normal heatingsequence #2.
Thermostat satisfies.
Burner off.
Blower post purge (15seconds).
9
8
10
7
Sequence of Operation
1. Simulated Resistive Device Fault:
a) If the FlammableVapor Sensor resistance is greater than 70,000 Ohms - the gas control immediately turns
off all outputs. Control waits and monitors resistance for 30seconds. Ifthe resistance is greater than 70,000 ohms
after 30seconds,the gas control proceeds to verify resistive delay for 2minutes and flashes 7 times witha three
second pause. This process is repeated 5 times until the control either returns to normal operation or proceeds
to a lockout mode flashing7 times witha 3 second pause.
b)If the FlammableVapor Sensor resistance is below 3000 ohms - The gas control immediately turns off all
outputs and proceeds to flash8 times then once withthree second pause. The error selfclears ifthe 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 withthree second pause. The error selfclears ifthe 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 flash8 times then three times withthree second pause. The error selfclears ifthe 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 flash4times with3 second pause. Blower continues to run until gas control is reset.
Power needs to be cycled to remove gas control fromTCO lockout.
Page 11
PDX Series
11

Sequence of Operation
3. Pressure Switch/Blower Temperature Fault:
a) Pressure switchclosedat start of call forheat - The control waits four seconds then, proceeds to flash
2times with 3second pause. The control waits 2minutes and thenturns onblower for 30seconds. The blower
turns off after 30seconds and the control waits for pressure switch to open. Any time the Pressure switch opens,
the blower turns on(or stays on) and the control proceeds to waiting for pressure switch to close.
b)Pressure switchorblowertemperature switchfailedopen - The control runs the blower for 30seconds
waiting for the pressure switch and/or blower temperature switch to close. Ifeither switch does not close in30
seconds,the blower turns off and the control flashes 3times with 3second pause. The control waits two
minutes before turning onthe blower for another 30seconds to see the circuit close. This cycle repeats as long as
there is a call for heat or until the circuit closes.
c) Pressure switchorblowertemperature switchopensduringburneroperation - The control turns off the
pilot and mainvalve,runs blower for 15 seconds (inter-purge) waiting for pressure switch and/or blower
temperature switch to close. Ifeither switch fails to close,the control proceeds as describedin3b above. Ifthe
circuit closes againby the end ofthe inter-purge,the recycle counter is incremented, ifthe recycle count has
not reachedits limit (4),another trial for ignitionbegins. Ifthe recycle count has beenreached, the control
turns off the blower and flashes 6times then 2times with 3second pause. The control waits 5 minutes before
repeating ignitionsequence.
4. Trial For IgnitionFault:
a) Pressure switchopensduringtrial - The control turns off igniter and pilot valve. The gas control proceeds
as describedin3b above. Ifthe pressure switch closes within30seconds the gas control will continue with trial for
ignitionstarting at blower pre-purge.
b) Flame Not Sensed- The control energizes the spark igniter attempting to light the pilot and prove flame. If
flame is not sensedwithin90 seconds,the igniter turns off, the pilot valve is closedand the gas control runs the
blower through post purge and flashes 6times then once with 3second pause. The control waits 5 minutes before
repeating the ignitionsequence.
5. Flame Sensing Fault:
a) Flame lost duringrun - The control turns off pilot and mainvalves,runs blower for 15 seconds (inter purge).
The control increments the recycle count,ifthe recycle count has not reachedits limit (4),another trial for
ignitionbegins. Ifthe recycle count has beenreached, the control turns off the blower and flashes 6times
then 3times with 3second pause. The control waits 5 minutes before repeating the ignitionsequence.
b) Flame sensedout of sequence - the control onlylooks for pilot flame whenthe blower is running. Ifflame is
present whenthe pilot valve is not open, the control proceeds to wait for flame loss and flashes 5 times with 3
second pause. This continues until flame is lost,once the flame signal is lost,the control flashes 6times then 4
times with 3second pause. The control waits 5 minutes before repeating the ignitionsequence.
Page12
PDX Series
12

Short flash,once every
four seconds
“Heartbeat”,alternates
bright/dim
Thermostat calling
for heat (no fault).
Short flash once per
second
Weak pilot signal
on last call for heat.
Twoflash,three second
pause
Pressure switch not
working-closed
position.
Three flash,three second
pause
Pressure switch or
blower temp.
switch not working
-open position.
Four flash,three second
pause
Excessive tank
temperature.
System must be
reset.
Fiveflash,three second
pause
Undesired-false
pilot flame present.
Troubleshooting
LEDStatus
Stand-by mode,
Waiting for call for
heat (no fault).
Control StatusService
Procedure
Probable Cause
Temperature demandis satisfied
Normal operation.
Adjust thermostat to
temp level
Tank temperature belowset point ofthermostat.
Normal operation.
Adjust thermostat to
temp level
1. Unstablepilot.
2. Pilot tube block or restricted.
3. Oxidation buildup on pilot electrode.
4. Wire damage to pilot assemblyor bad
connection at gas valve.
1. Page 15
2-4. Page 17
1. Pressure switch tubing kinked or blocked.
2. Blocked pressure tap on switch or blower.
3. Faulty pressure switch.
Page 18
1. Vent blockage or improper vent configuration.
2. Pressure switch tubing kinked or blocked.
3. Faulty pressure switch.
4. Blower not spinning up to speed.
5. Blower temp or exhaust temp too high
6. Faulty blower temperature switch.
7. Intakevent length exceeds exhaust vent length.
8. Frozen intakeor exhaust vent terminal.
1. Check vent or vent tables.
2&3Page 18
4. Page 20
5&6Page 22
8. Page 37
1. Thermal well sensor out of calibration.
2. Faulty gas control.
3. Plumbing leak
1. Page 24
2. Replace gas control,
page 26
1. Pilot valve stuck in open position.Replace gas control,
page 26
None,control LED not on
or flashing
Noelectrical
power
Control power switch in “OFF” position.
Supplyvoltage interrupted.Turn power on
Page 13
Observegreen LEDindicator on Electronic gas
control. Error flash codes are displayed with a
three second pause before repeating. Check
and repair thesystem as noted in the
troubleshooting table below.
Green LED
Indicator
PDX Series
13

Six-four flash,three
secondpause
Undesired-false
pilot flame
sensed.
System auto
resets.
Seven flash,three second
pause
FlammableVapor
Sensor fault
detected
Eight-one flash,three
secondpause
FlammableVapor
Sensor out of
specification.
Thermal well
sensor damaged
or unplugged
Eight-three flash,three
secondpause Gas valve
electronics fault
detected
LEDStatusControl StatusService
Procedure
Probable Cause
Pilot valve stuck in open position.Replace gas control,
page 26
WARNING: EXPLOSION HAZARD
* Indicates gasoline vapors were detected at potentially
explosive levels.
* Verify no gasoline vapors are still present
* Reset the control by cycling power to the appliance or
by cycling the ON/OFF switch.
* Replace the FlammableVapors Sensor element if a
gasoline spill event occurred.
Page 28
* Verify FlammableVapor Sensor (FVS) resistance is
not below 25 K Ohms.
* Check wiring to FVS and insure it is not shorted.
* Replace control if everything above checksout OK.
Page 28
1. Damage to thermal well wire.
2. Thermal well sensor resistance out of range.Page 24
1. Control needs to be reset.
2. Control is wet or physicallydamaged.
1. Interrupt power supply
2. Replace gas control,
page 26
Eight-four flash,three
secondpause
Gas valve fault
detected.
1. Control needs to be reset.
2. Control is wet or physicallydamaged.
1. Interrupt power supply
2. Replace gas control,
page 26
Troubleshooting
Six-three flash,three
secondpause
Pilot flame
extinguished.
System auto
resets.
1. Unstablepilot.
2. Pilot tube blocked or restricted.
3. Oxidation buildup on pilot electrode.
4. Wire damage to pilot assemblyor bad
connection at gas valve.
5. Insufficient combustion air.
6. Gas pressure is out of specification.
1. Page 15
2-4. Page 17
5. Refer to installation manual
Page 14
Six-twoflash,three
secondpause
Pressure switch
or blower temp
switch opened
during burner
operation.
System auto
resets.
1. Check vent or vent tables.
2&3Page 18
4. Refer to venting section of
installation manual
5. Page 20
6&7Page 22
8. Refer to installation
manual.
1. Vent blockage or improper vent configuration.
2. Pressure switch tubing kinked or blocked.
3. Faulty pressure switch.
4. Vent termination being affected by wind
5. Blower not spinning up to speed.
6. Blower temp or exhaust temp too high
7. Faulty blower temperature switch.
8. Insufficient combustion air.
Six-one flash,three
secondpause
Failedto light pilot.
System auto resets.
1. Unstablepilot.
2. Pilot tube blocked or restricted.
3. Oxidation buildup on pilot electrode.
4. Wire damage to pilot assemblyor bad
connection at gas valve.
1. Page 15
2-4. Page 17
PDX Series
14

Step 1. With main burner in operation, remove outer jacket door remove inner door as described in this manual,
see inner door removal, inspection and replacement section (page 35).
Step 2. To adjust for proper burning, loosen the air shutter nut, rotate the air shutter to close the opening in the
burner, then slowly rotate the air shutter open until flame becomes as blue as possible with a minimum of
yellow tips. Tighten the air shutter nut.
Too much air will cause the flame to lift off the burner ports and create noisy burner operation.
Too little air will result in soot formation.
Step 3. Replace inner door as described in this manual, observe burner operation. Burner should operate as
adjusted in step 2. If not, repeat air shutter adjustment compensating for proper burner operation with inner
door closed.
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.
b) Gas pressure is out of specification.
c) Pilot flame not fully engulfing spark/flame sensor.
d) Door was not sealed properly after servicing.
Main burner should light smoothly from pilot and burn with a blue flame with a minimum of yellow tips.
Steel burner models self adjust air to gas ratio mixture and do not have an adjustable air shutter. Cast iron burner can
have the gas and air mixture properly proportioned by adjusting the air shutter on the mixer face of the main burner
(see cast iron burner adjustment below).
Main burner must be free from any debris accumulation that may effect burner operation (see burner cleaning
procedure on page 14).
Burner Inspection and Air Shutter Adjustment.
Cast Iron Burner Air Shutter Adjustment
WARNING
Innerdoorandburnercomponents may be HOT when performingthis operation. Take
necessary precaution to prevent personal injury.
Air Shutter Nut
PDX SERVICEPROCEDURE I
Burner Operation Inspection,
Adjustment, Cleaning and Replacement
Air Shutter
Page15
PDX Series
15

Burner Cleaning
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.
Step 3. Remove outer jacket door and inner door per service procedure XIII on page 35.
Feedline nut
Pilot tubing nut
Igniter/flame
sense wire
Step 4. Disconnect pilot tube (7/16 wrench) and
feedline (¾ wrench) from gas control.
Step 5. Disconnect igniter/flame sensor wire from gas control.
Step 6. Remove burner assembly from combustion chamber.
Step 7. Thoroughly inspect burner surface area and burner port area and
remove any loose debris.
Step 8. For cast iron burners, inspect for any debris build up inside
burner casting.
Burner
surface area
Burner
port area
Step 9. Unscrew burner from main burner
orifice. On cast iron burners, loosen
air shutter nut and unscrew feedline
from burner.
Step 10. Remove main burner orifice from
feedline (½" wrench on steel
burners, 3/8" wrench on cast iron)
inspect orifice, clean or replace if
necessary.
Step 11. Reassemble burner and reinstall into water heater. Restore gas supply
and check for gas leaks.
Step 12 To resume operation follow the instruction located on the lighting
instruction label or the lighting instruction located in the installation
and operating manual.
PDX SERVICEPROCEDURE I
Burner Operation Inspection,
Adjustment, Cleaning and Replacement
Page16
L.P.Main burner
orifice. Left hand
thread
Main burner
orifice
PDX Series
16

PDX SERVICEPROCEDURE 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.
Step 2. Turn off gas supply to water heater.
Step 3. Remove outer jacket door and remove inner door per service proceedure XIII on page 35.
Feedline nut
Pilot tubing nut
Igniter/flame
sense wire
Step 4. Disconnect pilot tube nut (7/16 wrench) and feedline nut
(¾ wrench) from gas control.
Step 5. Disconnect igniter/flame sense wire from gas control.
Step 6. Remove burner assembly from combustion chamber.
Step 7. Remove pilot assembly from feedline (¼" nut driver).
Step 8. Visually inspect igniter/flame sense wire for damage. Replace
pilot if damage is found.
Step 9. With a multi-meter set to the ohms setting, check continuity
through igniter/flame sense wire. Replace pilot if no continuity.
Step 10. Visually inspect igniter/flame sense electrode for deterioration.
Replace pilot as necessary. Electrode should not be in contact
with pilot hood, If so, carefully adjust electrode to a gap
distance of 3/32" (.09) from pilot hood.
Step 11. Visually inspect igniter/flame sense electrode for oxidation
build up. Carefully clean any oxidation using very fine emery
cloth.
Step 13. Inspect pilot tubing and pilot orifice for blockage:
a) Remove ferrule nut from bottom of pilot assembly (7/16" wrench).
b) Remove pilot tube and pilot orifice.
c) Inspect pilot tubing and pilot orifice for blockage. Clean
or replace as necessary.
Step 14. Reassemble pilot and install to feedline. Reinstall burner assembly to water heater. Restore gas supply
and check for gas leaks.
Step 15 To resume operation follow the instruction located on the lighting instruction label or the lighting
instruction located in the installation and operating manual.
Step 12. Visually inspect pilot tubing for kinks or cracks. If damage is
found replace pilot.
Ferrule
nut
Pilot
orifice
Pilot
hood
Igniter/flame sense
electrode
Igniter/flame sense
wire
Pilot
tubing
Page17
PDX Series
17

``
PDX SERVICEPROCEDURE III
Pressure Switch Testing and
Replacement
Pressure Switch Testing WARNING
120volt potential exposure. Use caution
makingvoltage checks to avoidpersonal 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 assembly and
remove cover (see photo 1).
Step 3. Carefully remove pressure switch from blower housing (see photo 2)
2
Use amulti-meter set to the
ohms setting.With blower off,
check across pressure
switch terminals.
Are switch contacts open?
(no electrical continuity)
Check tubing and pressure tap
on switch for blockage.
Is there blockage?
Replace switch
(see page18)
Position gas valve power
switch to the “ON” position
and adjust thermostat
to call for heat,
this will start the blower.
Check with multi-meter, do
pressure switch contacts close
with blower running with the
switch in the vertical
postition?
With steps 1,2 &3complete,
disconnect wire leads from
pressure switch.
Y
N
Y
N
Switch contacts are OK.
See safety circuit trace
(page30)
Is vent
system
blocked
NSee blower testing
(page21)
Is blower OK?
Clear blockage
Y
N
Y
N
Correct blower
problem.
Pressure Switch
Slide pressure switch in direction of
arrow while tilting slightly away
from blower housing.
Is vent system length
within vent table
specifications
listed on page7or 8
Y
Reconfigure vent
system to be
compliant with
vent tables.
N
Y
Pressure switch
wire leads
Page18
Check tubing and
pressure tap on
switch for blockage.
Is there blockage?
N
Y
PDX Series
1
Exhaust pressure
switch
3
18

Exhaust Pressure Switch
ReplacementWARNING
120volt potential exposure. Use caution
to avoidpersonal injury.
Step 6. Reconnect wires from step 5 to new pressure switch.
Step 7. Reconnect tubing to new pressure switch.
Step 8. Carefully position pressure switch into blower housing.
Step 9. Position gas control power switch to “ON” position and verify proper heater operation.
Step 10. Replace control access cover from step 2.
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).
Pressure Switch
Slide pressure switch in direction of
arrow while tilting slightly away
from blower housing.
Step 3. Carefully remove pressure
switch from blower
housing (see photo 4)
Step 4. Disconnect tubing from
pressure switch.
(see photo 5)
Step 5. Disconnect yellow wires
from pressure switch
(see photo 6)
PDX SERVICEPROCEDURE III
Pressure Switch Testing and
Replacement
Page19
45
6 7
PDX Series
19

PDX SERVICEPROCEDURE IV
Blower Testing and Replacement
WARNING
115volt potential exposure. Use caution when
makingvoltage checks to avoidpersonal injury.
Blower Testing
Is there 115VAC across
terminals shown in
photo 13 ?
Incorrect supply
voltagepolarity
Determine
power source
problem and
correct.
Does blower energize Within 2
minutes?
Y
Disconnect cord set
shown in photo 9. Is
there 115VAC across
terminals shown in photo
12
N
See pressure switch
testing
Page18
Is there 115 VAC at
wall outlet?
Check power cord
for damage.
Y
N
Disconnect
pressure switch
tubing from blower.
(see photo 13)
Connect
manometer to
pressure tap of
blower.
(see photo 11)
With blower running,and exhaust
adapter removed from top of blower,
is there anegative pressure of -2.30"
to -2.60" W.C.?
Step 1. Position gas control power switch
to “ON” position and adjust control to call for heat.
Step 2. Remove the three screws (Phillips Screw driver)
from control access cover on blower assembly and
remove cover (see photo 8).
Reconnect cord set shown
in photo 8, is there
115VAC between blue wire
and green ground wire
(see photo 14)
Replace blower
Does cord set
have electrical
continuity?
Disconnect vent
system from top of
blower and remove
exhaust vent
adapter.
(see photo 15)
Does blower energize after 2
minutes, run for 30 seconds
and shut down?
N
Is there 115vac across blue
and green wires
(see photo 14)
Blower OK
Y
Repair or replace
power cord
Replace blower
Y
N
N
N
N
Y
Y
Y
Y
N
Pressure switch
tubing
Pressure tap
Remove exhaust
adapter
Shown with pressure
switch removed.
Green ground
wire
Blue wire
Replace blower
Y
Determine voltage
problem and correct.
N
Page20
8
9
10
1213
14
11
Replace gas
control
Y
Replace
cord set
N
PDX Series
20