Ultra Low NOx Residential & Light Duty Commercial Gas Power Vent 75 Gallon Models SERVICE MANUAL Troubleshooting Guide and Instructions for Service (To be performed ONLY by qualified service providers) Models Covered by This Manual: URG2PV75H*N ULG2PV75H76*N (*) Denotes Warranty Years Manual 238-51562-00B 1/19 Save this manual for future reference
The Bradford White UPV75 Series Through-The-Wall Gas Water Heaters Table of Contents UPV75 Service Procedure Introduction ................................................................................................................................4 --- How to Use This Manual..........................................................................................................5 --- Tools Required for Service.........................................................................................
UPV75 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! x Do not try to light any appliance. x Do not touch any electrical switch; do not use any phone in your building.
The Bradford White Introduction The new Bradford White URG2PV75H and ULG2PV75H 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 Bradford White Defender Safety System® (not available on all models).
UPV75 Series How to Use This Manual How to Use This Manual 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 UPV Series water heaters. Understanding the sequence of operation section of this manual will contribute greatly to troubleshooting the water heater. The Honeywell WV4462A Electronic Gas Control will display status codes in the event of abnormal operation.
UPV75 Series Power supply Gas Supply Pipe Approved Gas Type Gas Pressure Venting System Approved Vent Materials Minimum Clearance for Servicing Water Supply Pressure Gas Control ECO Limit Residential Temperature Set Point Range Commercial Temperature Set Point Range Blower Temperature Switch Pressure Switch Blower 6 6 Specifications Dedicated 115 VAC, 60 Hz, 15A. Minimum 1/2” NPT (schedule 40 black iron pipe recommended). Natural Gas, unit must match gas type supplied. 6.0” W.C. min. for Natural Gas, 14.
UPV75 Series Specifications Vent Tables Venting Specifications for: URG2PV75H ULG2PV75H 3" Diameter (7.6 cm) PVC Vent Connector Lengths # of Maximum Straight Minimum Straight Terminating Elbows Length ft. (m) Length ft. (m) Through the Wall 1 45 (13.7) 2 (.6) Through the Wall 2 40 (12.2) 2 (.6) Through the Wall 3 35 (10.7) 2 (.6) Through the Wall 4 30 (9.2) 2 (.6) Through the Roof Through the Roof Through the Roof Through the Roof 0 1 2 3 50 (15.2) 45 (13.7) 40 (12.2) 35 (10.7) 7 (2.
UPV75 Series Specifications Control Timings Ignition State Pre-purge Trial for Ignition Flame Stabilization Period Inter-purge Flame Failure Response Time Post-purge PS Fault Delay (failed open/close) Soft Lockout ECO Limit Lockout Verify Resistive Delay Flammable Vapor Sensor/Simulated Resistive Load Lockout Hardware Status Lockout 8 8 Timing 15 seconds 90 seconds 3 seconds 15 seconds 1.5 seconds (2 second. maximum; 1 second minimum.
UPV75 Series Sequence of Operation Power Up Sequence 1. Start Up. Upon power up, the control runs a safe-start check with a typical start-up delay of 5 seconds. 2. Simulative Resistive Device. To assure no outputs are energized if the “Simulated Resistive Device” is out of range, the control will test the “Simulated Resistive Device” for proper operating range. If the “Simulative Resistive Device” is out of range, the control LED immediately flashes 7 times with 3 second pause. Normal Heating Sequence 1.
UPV75 Series Sequence of Operation Normal Heating Sequence (cont.) 7. Steady state operation. During steady state operation, the control monitors: 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 shut down.
UPV75 Series Sequence of Operation Abnormal Operation (cont.) times, then 3 times twice with 3 second pause. The status self clears if the fault clears for at least 15 seconds. c. Water temperature in excess of ECO (energy cut out) limit -The gas control immediately turns off pilot & main valves and proceeds to flash 4 times with 3 second pause. Blower continues to run until gas control is reset.
UPV75 Series Sequence of Operation Abnormal Operation (cont.) 5. Flame sensing fault: a. Flame lost during run-the gas control turns off pilot and main valves, runs blower for 15 seconds (inter-purge). The gas control increments the recycle count, if the recycle count has not reached its limit (4), another trial for ignition begins. If the recycle count has been reached, the gas control turns off the blower and flashes 6 times then, 3 times with 3 second pause.
UPV75 Series Troubleshooting Observe green LED indicator on electronic gas control. Status 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 None, control LED not on or flashing Short flash, once every four seconds “Heartbeat” alternates bright/dim Control Status No electrical power Stand-by mode, waiting for call for heat (no fault). Thermostat calling for heat (no fault).
UPV75 Series LED Status Six-one flash, three second pause Control Status Failed to light pilot. System auto resets. Troubleshooting Probable Cause 1. Unstable pilot. 2. Pilot tube blocked or restricted. 3. Oxidation build up on pilot electrode. 4. Wire damage to pilot assembly or bad connection at the gas valve. Service Procedure Page 18 1. Check vent or vent tables. Six-two flash, three second pause Pressure switch or blower temp switch opened during burner operation. System auto resets. 1.
UPV75 Series UPV75 SERVICE PROCEDURE I Burner Operation Inspection, Cleaning and Replacement Burner Inspection 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.
UPV75 Series Burner Cleaning (cont.) Step 9. Remove manifold mount from burner inner door by removing (2) ¼” hex drive screws. Step 10. Use a stiff brush, compressed air and/or a vacuum to remove any debris build up from the manifold mount. Step 11. Remove (4) ¼” hex drive screws from main burner feedline mounting brackets. Remove brackets from orifices by hand by turning counterclockwise. Step 12. Remove main burner orifices from feedline (1/2” wrench) inspect orifice, clean or replace if necessary.
UPV75 Series UPV75 SERVICE PROCEDURE II Pilot Inspection, Testing and Replacement Pilot Inspection, Testing and Replacement Step 1. Step 2. Step 3. Step 4. Step 5. Step 6. Step 7. Position the gas control power switch to the “OFF” position and unplug the heater from the wall outlet. Turn off gas supply to the water heater. Remove outer jacket door. Disconnect pilot tube (7/16” wrench) and feedline (¾” wrench) from gas control. Disconnect igniter/flame sensor wire from gas control.
UPV75 Series UPV75 SERVICE PROCEDURE II Pilot Inspection, Testing and Replacement Pilot Inspection, Testing and Replacement (cont.) Step 13.Visually inspect igniter/flame sense electrode for oxidation build up. Carefully clean any oxidation using very fine emery cloth. Step 14.Remove pilot assembly from the burner assembly (¼” nut driver). Step 15.Visually inspect igniter/flame sense wire for damage. Replace pilot if damage is found. Step 16.
UPV75 Series Pressure Switch Testing Step 1. Step 2. Step 3. UPV75 SERVICE PROCEDURE III Pressure Switch Testing and Replacement WARNING 115 volt potential exposure. Use caution to avoid personal injury. Position power switch on gas control to the “OFF” position. Remove the three screws (Phillip’s screw driver) from control access cover on blower assembly and remove cover (see photo 1). Carefully remove pressure switch from blower housing (see photo 2).
UPV75 Series Pressure Switch Replacement Step 1. UPV75 SERVICE PROCEDURE III Pressure Switch Testing and Replacement ‘WARNING 115 volt potential exposure. Use caution to avoid personal injury. Position gas control power switch to “OFF” position. Step 2. Remove the three screws (Phillip’s screw driver) from control access cover on blower assembly and remove cover (see photo 3). Step 3. Remove pressure switch from blower housing by removing the two T10 screws (see photo 4a).
UPV75 Series Blower Testing Step 1. Step 2. Position gas control power switch to “ON” position and adjust control to call for heat. Remove the three screws (Phillip’s screw driver) from control access cover on blower assembly and remove cover (see photo 7). UPV75 SERVICE PROCEDURE IV Blower Testing & Replacement WARNING 115 volt potential exposure. Use caution to avoid personal injury.
UPV75 Series UPV75 SERVICE PROCEDURE IV Blower Testing & Replacement Blower Removal Step 1. Position gas control power switch to “OFF” position and adjust control to call for heat. 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.
UPV75 Series UPV75 SERVICE PROCEDURE V Blower Temperature Switch Testing and Replacement Blower Temperature Switch Testing Step 1. Step 2. Step 3. Position power switch on gas control to the “OFF” position. Remove the three screws (Phillip’s screw driver) from control access cover on blower and remove cover (see photo 14). Locate blower temperature switch (see photo 15). WARNING 115 volt potential exposure. Use caution to avoid personal injury.
UPV75 Series UPV75 SERVICE PROCEDURE V Blower Temperature Switch Testing and Replacement Blower Temperature Switch Replacement Step 1. Position gas control power switch to the “OFF” position and unplug heater from wall outlet. Step 2. Remove the three screws (Phillip’s screw driver) from the control access cover on blower and remove cover (see photo 16). Step 3. Locate blower temperature switch (see photo 17). Step 4. Disconnect red and yellow wire leads from switch. Step 5.
UPV75 Series UPV75 SERVICE PROCEDURE VI Gas Control Testing and Replacement Line Pressure The gas control is designed for a maximum line pressure of 14.0” W.C. and a minimum line pressure of 1.0” W.C. over the water heater’s rated manifold pressure (check rating plate). Line pressure must be checked with the main burner on and off to assure proper readings. Manifold Pressure Testing (This procedure presumes a maximum line pressure of 14.0” W.C.) Step 1. Set the gas control to the “OFF” position. Step 2.
UPV75 Series UPV75 SERVICE PROCEDURE VI Gas Control Testing and Replacement ECO (Energy Cut Out) The Honeywell gas control is designed with an ECO device that will reset. To reset the gas control after an status code (4), turn the gas control knob to the “OFF” position and wait a minimum of (5) minutes before relighting following the instructions located on the lighting instruction label or the lighting instructions located in the installation and operation manual.
UPV75 Series UPV75 SERVICE PROCEDURE VI Gas Control Testing and Replacement Gas Control Removal From Water Heater Step 1. Position the gas control power switch to the “OFF” position and unplug heater from wall outlet. Step 2. Drain the heater to a point below the gas control level. Step 3. Turn off the gas supply to the water heater and disconnect gas piping from the gas control. Step 4. Disconnect wire harnesses from the gas control. Step 5. Remove the outer jacket burner access door. Step 6.
UPV75 Series UPV75 SERVICE PROCEDURE VII Simulative Resistance Device Testing and Replacement Simulative Resistance Device Testing Step 1. Position power switch on gas control to the “OFF” position. Step 2. Disconnect simulated resistive device harness from gas control. Step 3. Using a multi-meter set to the ohms setting, check resistance of simulative resistance device. Resistance must be between 3,000 ohms and 48,000 ohms. If outside of this range replace the simulated resistive device.
UPV75 Series UPV75 SERVICE PROCEDURE VIII Safety Circuit Voltage Trace Safety Circuit Voltage Trace NOTE: This procedure assumes a cool tank. WARNING 115 volt potential exposure. Use caution to avoid personal injury. Remove three screws (Phillip’s screw driver) from control access cover on the blower and remove the cover (see photo 21).
UPV75 Series UPV75 SERVICE PROCEDURE IX 115 VAC Trace 115 VAC Circuit Trace Step 1. Verify 115 VAC and proper polarity at wall outlet. Step 2. With unit plugged in and control power switch in the “ON” position verify LED status. 30 30 WARNING 115 volt potential exposure. Use caution to avoid personal injury.
UPV75 Series UPV75 SERVICE PROCEDURE X Dip Tube Inspection & Replacement Diptube Inspection & 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.
UPV75 Series UPV75 SERVICE PROCEDURE XI Anode Inspection & Replacement Anode Inspection & Replacement WARNING Step 1. Step 2. Step 3. Step 4. Step 5. Step 6. Step 7. 32 32 Water Heater components and stored water may be HOT when performing the following steps in this procedure. Take necessary precaution to prevent personal injury. Position on/off switch of gas control valve to the “OFF” position and unplug water heater from wall outlet. Turn off cold water supply to water heater.
UPV75 Series UPV75 SERVICE PROCEDURE XII Flue Baffle Inspection & Replacement Flue Baffle Inspection and Replacement Step 1. Position the 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. Unplug cord sets from the blower (see photo 28). Step 4. Remove the three blower mounting screws (1/4” nut driver) (see photo 28). Step 5. Remove blower with gasket from water heater. Step 6.
UPV75 Series UPV75 SERVICE PROCEDURE XIII Inner Door/Gasket Removal, Inspection & Replacement Inner Door Removal Procedure Step 1. Step 2. Step 3. Step 4. Step 5. Step 6. Step 7. Step 8. Position gas control power switch to the “OFF” position. Remove outer jacket burner access door. Disconnect main burner feedline (3/4” wrench), pilot tube (7/16” wrench) and white igniter/flame sense wire from the gas valve. Remove (4) ¼” hex drive screws from right side inner door.
UPV75 Series UPV75 SERVICE PROCEDURE XIII Inner Door/Gasket Removal, Inspection & Replacement Inner Door Gasket Replacement Procedure WARNING If the information in these instructions is not followed exactly, a fire or explosion may result causing property damage, personal injury or death. Step 1. After inspection of inner door as noted in step 8, completely remove gasket and adhesive residue from right and left side inner doors as needed. Step 2.
UPV75 Series UPV75 SERVICE PROCEDURE XIII Inner Door/Gasket Removal, Inspection & Replacement Installation of Inner Door With Gasket (cont.) Step 6. Replace outer jacket burner access door. Step 7. To resume operation follow the instructions located on the lighting instruction label or the lighting instructions located in the installation and operation manual. WARNING Stripped fastener connections may allow for seal breach of inner door.
UPV75 Series Glossary of Terms Frozen Exhaust Vent Terminal If the 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 status code. Once the blockage is removed (through melting or other means) the controls will let the burner operate.
UPV75 Series 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. Blower Complete Air Mixing Inlet Cover Pressure Switch Blower Temp. Switch Blower Gasket Blower Power Cord Flue Reducer Heat Trap Outlet Hot Water Outlet Anode Flue Core Heat Trap Inlet 38 38 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. Inlet Dip Tube Wire Harness T&P Valve ¾ NPT Plug Burner Assy. Pilot Assembly Pilot Orifice Main Burner Right Side Inner Door Screw #8-15 x ¾ Screw #10-12 x ¾ Glossary of Terms 23. Main Burner Orifice 24.
