PDX Series Powered Direct Vent Gas Water Heaters 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 Manual 238-49770-00A Save this manual for future reference
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 & Therma
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.
PDX Series 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.
How to Use This Manual PDX Series 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.
Specifications PDX Series 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.
Specifications PDX Series Vent Tables 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 Maximum 48, 65 gal.
Specifications PDX Series Vent Tables Part II-Venting Specifications for: 40 Gallon 50 Gallon IMPORTANT The minimum equivalent length for the exhaust portion of the vent is 7 feet. The maximum equivalent vent length for the exhaust is 35 feet for 2" diameter pipe and 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 are provided for your quick reference, some installations may require a greater number of elbows.
PDX Series Specifications Control Timings Ignition State Timing Pre-purge 15 Seconds Trial for Ignition 90 Seconds Flame Stabilization Period 3 Seconds Inter-purge 15 Seconds Flame Failure Response Time 1.5 Seconds (2 second. Maximum; 1 second minimum.
PDX Series 1 Sequence of Operation Start Up. Upon power up, the control runs a safe-start check with a typical start-up delay of 1-5 seconds. 2 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.
PDX Series Sequence of Operation Steady state operation. 7 During Steady State Operation the Control Monitors: Thermostat temperature sensor- When set point temperature is satisfied, gas valve is shut down and blower will post purge for 15 seconds. Control LED flashes a short flash once every 4 seconds (idle) status code. Pressure switch / Blower temperature switch- If either switch opens, pilot valve and main valve is shut down. The blower continues to run for 30 seconds attempting to close the circuit.
PDX Series Sequence of Operation 3. Pressure Switch/Blower Temperature Fault: a) Pressure switch closed at start of call for heat - The control waits four seconds then, proceeds to flash 2 times with 3 second pause. The control waits 2 minutes and then turns on blower for 30 seconds. The blower turns off after 30 seconds and the control waits for pressure switch to open. Any time the Pressure switch opens, the blower turns on (or stays on) and the control proceeds to waiting for pressure switch to close.
Troubleshooting PDX Series Green LED Indicator Observe green LED indicator on Electronic gas control. Error flash codes are displayed with a three second pause before repeating. Check and repair the system as noted in the troubleshooting table below. LED Status Control Status Probable Cause Service Procedure None, control LED not on or flashing No electrical power Control power switch in “OFF” position. Supply voltage interrupted.
Troubleshooting PDX Series LED Status Six-one flash, three second pause Six-two flash, three second pause Six-three flash, three second pause Six-four flash, three second pause Control Status Probable Cause 1. Unstable pilot. 2. Pilot tube blocked or restricted. Failed to light pilot. 3. Oxidation build up on pilot electrode. System auto resets. 4. Wire damage to pilot assembly or bad connection at gas valve. 1. Vent blockage or improper vent configuration. Pressure switch 2.
PDX SERVICE PROCEDURE I Burner Operation Inspection, Adjustment, Cleaning and Replacement PDX Series Burner Inspection and Air Shutter Adjustment. At periodic intervals (every 6 months) a visual inspection should be made of the pilot and main burner for proper operation and to assure no debris is accumulating. Pilot flame should be stable, some causes for an unstable pilot flame are: a) Water heater vent is less than the allowable vent length. b) Gas pressure is out of specification.
PDX SERVICE PROCEDURE I Burner Operation Inspection, Adjustment, Cleaning and Replacement PDX Series 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. 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.
PDX Series PDX SERVICE PROCEDURE II Pilot testing, Cleaning and Replacement Pilot Inspection, Testing and Replacement Step 1. Position gas control power switch to the “OFF” position and unplug heater from wall outlet. 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. Igniter/flame sense wire Step 4. Disconnect pilot tube nut (7/16 wrench) and feedline nut (¾ wrench) from gas control. Step 5.
PDX SERVICE PROCEDURE III Pressure Switch Testing and Replacement PDX Series Pressure Switch Testing WARNING 120 volt potential exposure. Use caution making voltage checks to avoid personal injury. Step 1. Position power switch on gas control to the “OFF” position. Step 2. Remove the three screws (Phillips screw driver) from control access cover on blower assembly and remove cover (see photo 1). Step 3.
PDX SERVICE PROCEDURE III Pressure Switch Testing and Replacement PDX Series Exhaust Pressure Switch Replacement WARNING 120 volt potential exposure. Use caution to avoid personal injury. Step 1. Position gas control power switch to “OFF” position. Step 2. Remove the three screws (Phillips screw driver) from control access cover on blower assembly and remove cover (see photo 3). Pressure Switch 5 4 Step 3.
PDX SERVICE PROCEDURE IV Blower Testing and Replacement PDX Series WARNING 115 volt potential exposure. Use caution when making voltage checks to avoid personal injury. Blower Testing 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).
PDX SERVICE PROCEDURE IV Blower Testing and Replacement PDX Series Blower removal Step 1. Position gas control power switch to the “OFF” position. Step 2. Unplug blower power cord from wall outlet. Step 3. Disconnect vent system from exhaust adapter on top of blower. Step 4. Remove exhaust adapter from blower (blade screw driver) and retain for use on new blower Step 5. Unplug cord sets from blower. Step 6. Remove vertical air intake bracket. Step 7. Disconnect vertical air intake from blower.
PDX SERVICE PROCEDURE V Blower Temperature Switch Testing and Replacement PDX Series Blower Temperature Switch Testing. WARNING 120 volt potential exposure. Use caution to avoid personal injury. Step 1. Position power switch on gas control to the “OFF” position. Step 2. Remove tubing from inlet pressure tap. Step 3. Remove the three screws (Phillips screw driver) from control access cover on blower and remove cover (see photo 15). Step 4.
PDX SERVICE PROCEDURE V Blower Temperature Switch Testing and Replacement PDX Series Blower Temperature Switch Replacement. WARNING 120 volt potential exposure. Use caution to avoid personal injury. Step 1. Position gas control power switch to the “OFF” position and unplug heater from wall outlet. Step 2. Remove the three screws (Phillips screw driver) from the control access cover on blower and remove cover. (see photo 17) Step 3. Locate blower temperature switch (see photo 18) Step 4.
PDX SERVICE PROCEDURE VI Gas Control/Thermal Well Testing and Replacement PDX Series Gas Control Testing See pages 27 & 28 for gas control input & output testing. Thermal Well Testing Disconnect thermal well wire harness If Control has gone into TCO lockout due to excessive tank temperature (four flash, 3 second pause) reset control by rotating knob of temperature control to the minimum setting for at least 6 seconds before returning to desired temperature setting. Observe heater operation.
PDX SERVICE PROCEDURE VI Gas Control/Thermal Well Testing and Replacement PDX Series WARNING Stored water may be HOT when performing the following steps in this procedure. Take necessary precaution to prevent personal injury. Determine Water Temperature Inside Tank Note: It is important to understand once the resistance for the thermal well is determined from page 25, water flow through the heater should not occur. Prior to performing the steps below, turn off the cold water supply to the water heater.
PDX SERVICE PROCEDURE VI Gas Control & Thermal Well Testing and Replacement PDX Series Gas Control & Thermal Well Removal From Water Heater Gas Control Step 1. Position gas valve power switch to the “OFF” position and Unplug Heater from power supply. Step 2. Drain heater to a point below the gas control level. Step 3. Turn off gas supply to water heater and disconnect gas piping from gas control. Step 4. Disconnect wire harnesses and burner assembly from gas control. Step 5.
PDX SERVICE PROCEDURE VI Gas Control & Thermal Well Testing and Replacement PDX Series Gas Control Assembly to Thermal Well Step 1. Install threaded end of thermal well into tank. Be sure thermal well flange is positioned as shown in photo 22 for proper control alignment. Step 2. Route wire leads back into relief opening. (see photo 23) Step 3. Align slots located on thermal well flange with tabs located on back of gas control (see photo 22 & 23) 22 Thermal well flange slots Step 4.
PDX SERVICE PROCEDURE VII Flammable Vapors Sensor Testing PDX Series Flammable Vapor Device Testing Step 1. Position power switch on gas control to the “OFF” position. Step 2. Disconnect flammable vapor sensor from gas control. Step 3. Using a multi-meter set to the ohms setting check resistance of flammable vapor sensor. (see caution below) Resistance must be within 3,000 ohms and 48,000 ohms. If outside of this range replace flammable vapor sensor.
PDX SERVICE PROCEDURE VIII Safety Circuit Voltage Trace PDX Series Safety Circuit Voltage Trace WARNING 120 volt potential exposure. Use caution making voltage checks to avoid personal injury. NOTE: This procedure assumes a cool tank. 24 Step 2. Remove three screws (Phillips Screw driver) from control access cover on blower and remove cover (see photo 24).
PDX SERVICE PROCEDURE IX 120 VAC Trace PDX Series WARNING 120 volt potential exposure. Use caution making voltage checks to avoid personal injury. 120 VAC Circuit Trace Step 1. Verify 120VAC and proper polarity at wall outlet. Step 2. With unit plugged in and control power switch in the “ON” position verify LED status. LED status None, Control LED not on or flashing. LED status Short flash, once every four seconds. LED status “Heartbeat”, alternates bright/dim.
PDX Series PDX SERVICE PROCEDURE X Dip Tube Inspection and replacement Dip Tube Inspection and Replacement WARNING Water Heater components and stored water may be HOT when performing the following steps in this procedure. Take necessary precaution to prevent personal injury. Step 1. Position on/off switch of gas control valve to “OFF” position and unplug water heater from wall outlet. Step 2. Turn off cold water supply to water heater.
PDX Series PDX SERVICE PROCEDURE XI Anode Inspection and replacement Anode Inspection and Replacement WARNING Water Heater components and stored water may be HOT when performing the following steps in this procedure. Take necessary precaution to prevent personal injury. Step 1. Position on/off switch of gas control valve to the “OFF” position and unplug water heater from wall outlet. Step 2. Turn off cold water supply to water heater.
PDX SERVICE PROCEDURE XII Flue Baffle Inspection and replacement PDX Series Remove blower to gain access to flue baffle Disconnect vent system from exhaust adapter. 31 Step 1. Position gas control power switch to the “OFF” position and unplug blower from wall outlet. Step 2. Disconnect vent system from exhaust adapter on top of blower. Step 3. Disconnect intake air piping. Step 4. Unplug cord sets from blower. (see photo 31). Step 5.
PDX SERVICE PROCEDURE XIII Inner Door/Gasket Removal, Inspection Replacement and Reinstallation PDX Series Inner Door Removal Procedure. Step 1. Slide switch of the Electronic Gas Control to the “OFF” position and unplug from wall. Step 2. Remove outer jacket burner access door. Step 3. Disconnect wire connections from Electronic Gas Control. Step 4. Right side Inner Door Removal. a) Remove wire tie from feedline. b) Remove (2) 1/4" hex drive screws from right side inner door.
PDX Series Installation of Inner Door With Gasket. Step 7. Clean any residual gasket residue or other debris from combustion chamber surface before installing the inner door/gasket assembly. Step 8. Place the left side inner door into position first. Firmly position the radiused channel of the inner door around the feedline. Using the 1/4” hex drive screws from step 3d, secure left side inner door in place. DO NOT OVER TIGHTEN SCREWS.
PDX Series PDX SERVICE PROCEDURE XIII Inner Door/Gasket Removal, Inspection Replacement and Reinstallation Installation of inner door with gasket (continued from page 36). Step 10. Firmly place right side inner door flange against the left side inner door flange and secure with two ¼” drive screws from step 3c. DO NOT OVER TIGHTEN SCREWS. Step 11.
PDX Series Frozen intake or exhaust vent terminal If an intake or exhaust vent terminal is blocked with ice or snow due to severe conditions, the pressure switch and control will not allow the burner to operate. This will result in a three flash error code. Once the blockage is removed (through melting or other means) the controls will let the burner operate.
PDX Series BTU GPM Hz KW/h LED NPT Ohms PSI RPM TCO VAC W.C.
Parts List PDX Series 1. Blower Assembly 2. Blower Temp. Switch 3. Pressure Switch 4. Blower Gasket 5. Tee and Vent Pipe Assy. 6. Vent Adapter with Term. 7. Intake Terminal 8. Vent Terminal Elbow 9. Exhaust Adapter 10. Condensate Hose Kit 11. Flue Reducer 12. Heat Trap Insert (outlet) 13. Heat Trap Insert (inlet) 14. Hot Water Outlet Anode 15. Cold Water Inlet Diptube 16. Flue Baffle 17. Blower Harness 18. T&P Relief Valve 19. ¾ NPT PLUg 20. Direct Vent Boot Escutcheon 21. Air Intake Boot 22.