Super High Efficiency Atmospheric 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: HE440S*F(BN,SX) HE450S*F(BN,SX) (*) Denotes Warranty Years Manual 238-50216-00A Save this manual for future reference
Table of Contents Section Page Introduction ______________________________________________ 5 How to Use this Manual _____________________________________ 6 Tools Required for Service ___________________________________ 6 Specifications_____________________________________________ 7 Sequence of Operation _____________________________________ 9 Power Up Sequence Normal Heating Sequence Abnormal Operation Troubleshooting __________________________________________ 13 Burner Maintenance________________________
WARNING If the information in these instructions is not followed exactly, a fire or explosion may result causing property damage, personal injury, or death. What to do if you smell gas: x Do not try to light any appliance x Do not touch any electrical switch; do not use any phone in your building x Immediately call your gas supplier from a neighbor’s phone. Follow the gas supplier’s instructions. x If you cannot reach your gas supplier, call the fire department.
WARNING Water heaters are heat producing appliances. To avoid damage or injury, do not store materials against the water heater or any of its components. Use proper care to avoid unnecessary contact, especially by children, with the water heater and its components. Under no circumstances must flammable materials, such as gasoline or paint thinner be used or stored in the vicinity of this water heater or in any location in which the fumes could reach the water heater.
Introduction The Bradford White DEFENDER Safety System® The Bradford White DEFENDER Safety System was designed to resist the ignition of flammable vapors that can occur outside of the water heater. Use and installation are nearly identical to previous versions of atmospherically fired and vented water heaters. A number of exclusive design features are incorporated in the system that will require additional knowledge on the part of the qualified service provider.
How to Use this Manual in sufficient quantity to prevent normal combustion, the flammable vapor sensor recognizes this and shuts down the pilot and main burner. Should the flammable vapors continue to burn, the flame arrestor prevents the flames from traveling backwards and igniting vapors outside of the combustion chamber. And, the resettable thermal switch will open and shut down the pilot and main burner.
Specifications Power Supply Dedicated 120VAC, 60 Hz, 15A Minimum 1/2” (Schedule 40 black iron pipe Gas Supply Pipe recommended) Approved Gas Type Natural or Propane; unit must match gas type supplied Gas Pressure 5” w.c. minimum for Natural Gas; 11” w.c. for Propane; 14” w.c.
Specifications Control Timings Ignition State Timing Pre-purge 15 seconds Trial for Ignition 90 seconds Flame Stabilization Period 3 seconds Interpurge 15 seconds 1.
Sequence of Operation Power Up Sequence 1. Start-up: Upon power up, the gas control runs a safe start check with a typical delay of 5 seconds. 2. Flammable Vapor Verification: The gas control verifies that the Flammable Vapor Sensor is in the proper operating range prior to energizing any components. If the sensor is within the proper range, the gas control resumes normal operation. If the Flammable Vapor Sensor is out of range, the gas control LED immediately flashes 7 times with a 3 second pause.
Sequence of Operation Normal Heating Sequence (cont’d) 7. Steady State Operation: During steady state operation, the gas control monitors: Temperature Sensor: When the setpoint temperature is satisfied, the gas control is shutdown, and the blower will postpurge for 15 seconds. The gas control LED flashes a short flash once every 4 seconds (Idle status code). Pressure Switch / Blower Temperature Switch: If either switch opens, the pilot and main valves are shutdown.
Sequence of Operation Abnormal Operation (cont’d) 2. Temperature Sensor Fault: A) Temperature Sensor Open Circuit: The gas control immediately turns off all outputs and proceeds to flash 8 times then 2 times with a 3 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°F: The gas control immediately turns off all outputs and proceeds to flash 8 times then 2 times with 3 second pause.
Sequence of Operation Abnormal Operation (cont’d) 4. Trial for Ignition Fault: A) Pressure Switch / Blower Temperature Switch Opens During Trial: The gas control stops the trial for ignition. The gas control monitors the pressure switch until it closes. If the pressure switch closes within 30 seconds, the gas control will continue with the trial for ignition starting at blower pre-purge. B) Flame Not Sensed: The gas control energizes the spark igniter attempting to light the pilot and prove flame.
Troubleshooting Observe the green LED on the water heater gas control. Error codes are displayed with a 3 second pause before repeating. Once the error code is known, check and repair the water heater, as recommended in the table below. LED Status Probable Cause Control power switch in "OFF" None (LED not Electrical pow er not position. on or flashing) present Supply voltage interrupted.
Troubleshooting LED Status Six flashes, two flashes, three second pause (Soft Lockout) Control Status Probable Cause 1. Vent blockage or improper vent configuration Pressure switch or 2. Pressure switch tubing kinked or blower temp switch blocked opened during 3. Faulty pressure switch burner operation, 4. Blower not spinning up to speed system auto resets 5. Damper (inside blower) not fully after (5) minutes opening 6. Faulty blower temperature switch Service Procedure 1.
Burner Maintenance 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. The pilot flame should be stable. Some causes for an unstable pilot flame are: a) Gas pressure is out of specification. b) Pilot flame not fully engulfing spark/flame sensor. The main burner should light smoothly from the pilot and burn with a blue flame with a minimum of yellow tips.
Burner Maintenance Burner Cleaning Procedure (cont’d) Step 5. Remove the (4) 1/4” hex drive screws holding the right side inner door in place. (4) 1/4” hex drive screws Right side inner door Step 6. Disconnect the pilot tube using a 7/16” wrench and the main burner feedline with a 3/4” wrench from the gas control. Pilot and main feedlines Step 7. Disconnect the spark igniter/flame sensor wire from gas control. Gas control Spark igniter/flame sensor wire Step 8. chamber.
Pilot Maintenance Burner Cleaning Procedure (cont’d) Step 12. Reassemble the burner assembly and reinstall into the water heater. Restore gas supply and check for gas leaks. Step 13. To resume operation, follow the instructions located on the water heater lighting instruction label. Or, use the lighting instructions located in the water heater installation and operating manual. Pilot Inspection, Testing and Replacement Step 1.
Pilot Maintenance Pilot Inspection, Testing and Replacement (cont’d) Step 7. Disconnect the spark igniter/flame sensor wire from gas control. Gas control Spark igniter/flame sensor wire Step 8. chamber. Remove the burner assembly from the combustion Burner assembly Step 9. Remove the pilot assembly from the main feedline using a 1/4" nut driver. Pilot assembly 1/4” nut driver Step 10. Visually inspect the spark igniter/flame sense wire for damage. Replace the pilot assembly, if damage is found.
Blower Replacement Pilot Inspection, Testing and Replacement (cont’d) Step 14. Visually inspect the pilot tubing for kinks or cracks. If damage is found, replace the pilot assembly. Step 15. Inspect the pilot tubing and pilot orifice for blockages: a) Remove ferrule nut from the bottom of the pilot assembly using a 7/16" wrench. b) Remove the pilot tube and pilot orifice. c) Inspect the pilot tubing and pilot orifice for blockages. Clean or replace, as necessary. Step 16.
Blower Replacement Blower Removal & Installation (cont’d) Step 3. Disconnect the vent system from the draft hood that is mounted on top of the blower. Vent system Step 4. Remove the draft hood from the blower and retain it for use on the new blower. Draft hood Blower Step 5. Unplug the cord sets from the blower. Cord sets Step 6. Remove the three blower mounting screws using a 1/4” nut driver and retain for later use. 1/4” nut driver Blower Step 7. heater.
Temperature Sensor Testing Blower Removal & Installation (cont’d) Step 13. Reconnect the cord sets from Step 5. Step 14. Plug the water heater into the wall outlet. Step 15. To resume operation, follow the instructions located on the water heater lighting instruction label. Or, use the lighting instructions located in the water heater installation and operating manual. Temperature Sensor Testing CAUTION Do not use standard multi-meter probes for this testing. Doing so will damage the connector.
Temperature Sensor Testing Temperature Sensor Testing (cont’d) Step 3. Disconnect the spark igniter from the gas control. Gas control Spark igniter/flame sensor wire Step 4. Disconnect the gas control power harness from the bottom of the control. Gas control power harness Step 5. Disconnect the flammable vapor sensor / resettable thermal switch (FVS/RTS) harness from the bottom of the control. FVS/RTS harness Step 6.
Determine Tank Temperature Temperature Sensor Testing (cont’d) CAUTION Do not use standard multi-meter probes for this testing. Doing so will damage the connector. Use special pin type electronic probes or small diameter wire pins inserted into connector. Step 9. With a multi-meter set to the ohms setting, measure the resistance between the middle and right side wires. Multi-meter leads Step 10. With a multi-meter set to the ohms setting, measure the resistance between the middle and left side wires.
Determine Tank Temperature Determine Water Temperature Inside Tank (cont’d) Step 1. position. Move the gas control power switch to the “OFF” Gas control power switch Step 2. Draw approximately 4 gallons of water from the drain valve into a container and discard. Draw an additional gallon and immediately measure the water temperature using an accurate thermometer. It may be necessary to open a hot water faucet to allow heater to drain. Step 3.
Gas Control Removal Gas Control Removal Step 1. position. Move the gas control power switch to the “OFF” Step 2. Unplug the water heater from the wall outlet. Gas control power switch Blower (water heater) power cord Step 3. Drain the water heater to a point below the gas control level. Step 4. Turn off the gas supply to the water heater and disconnect the gas piping from the gas control. Step 4.
Gas Control Assembly Gas Control Disassembly / Assembly Following the steps below allows for the removal of the gas control from the temperature sensor well without removing the temperature sensor well from the tank. Step 1. position. Move the gas control power switch to the “OFF” Gas control power switch Step 2. Unplug the water heater from the wall outlet. Blower (water heater) power cord Step 3. Turn off the gas supply to the water heater and disconnect the gas piping from the gas control.
Flammable Vapor Sensor Testing Gas Control Disassembly / Assembly (cont’d) Step 6. Using a slotted screwdriver (or a T-15 torx), remove the screw (holding the cover on) at the bottom of the gas control. Slotted screwdriver Step 7. Depress both tabs on the top of the gas control cover and pull to remove. Step 8. Disconnect the temperature sensor wire harness from the gas control board. Temperature sensor wire harness Flammable Vapor Sensor Testing Step 1. position.
120 VAC Circuit Trace Flammable Vapor Sensor Testing (cont’d) Step 3. Using a multi-meter set to the ohms setting, measure the resistance of the flammable vapor sensor. Step 4. Using a multi-meter set to the ohms setting, measure the resistance of the resettable thermal switch (between the left two pins of the wire harness). The resistance must be between 3,000 and 48,000 ohms for both the switch and sensor.
Anode Inspection Dip Tube Inspection and Replacement (cont’d) Step 7. Upon completion of the inspection or subsequent replacement, reinstall the inlet nipple/diptube into the water heater. Connect the nipple to the plumbing system, resume water supply to the water heater, refill the water heater and check for leaks. Step 8. To resume operation, follow the instructions located on the water heater lighting instruction label.
Blower Removal Remove the Blower to Gain Access to the Flue Baffle Step 1. position. Move the gas control power switch to the “OFF” Gas control power switch Step 2. Unplug the water heater from the wall outlet. Blower (water heater) power cord Vent system Step 3. Disconnect the vent system from the draft hood that is mounted on top of the blower. Draft hood Blower Step 4. Unplug the cord sets from the blower. Cord sets Step 5.
Blower Removal Remove the Blower to Gain Access to the Flue Baffle (cont’d) Blower Step 6. heater. Remove the blower from the top of the water Top of water heater Water heater tank flue Step 7. Remove the flue baffle from the water heater. Flue baffle Step 8. Inspect the baffle for deterioration and missing restrictors. Clean any scale or debris build-up. Replace with a new baffle, as necessary. Step 9. Reinstall the baffle into the flue.
Inner Door Removal Inner Door Removal Procedure Step 1. position. Move the gas control power switch to the “OFF” Gas control power switch Step 2. Unplug the water heater from the wall outlet. Blower (water heater) power cord Step 3. Remove the outer door. Outer door Step 4. Remove (4) 1/4” hex drive screws from the right side inner door. (4) 1/4” hex drive screws Left side inner door Step 5. inner door. Remove (2) 1/4” drive screws from the left side 1/4” hex drive screws Step 6.
Inner Door Gasket Replacement Inner Door Removal Procedure (cont’d) Step 7. Inspect both inner doors for any of the following imperfections: tears, missing material, cracks, dirt or debris, lack of adhesion to the inner door, material left on combustion chamber, or any other imperfections that will inhibit a proper seal. If any of the imperfections above are present, replace the inner door gasket following the Inner Door Gasket Replacement Procedure.
Inner Door Installation Inner Door Installation with Gasket WARNING Stripped fastener connections may allow for an inner door seal breach. A seal breach may result in a fire or explosion, causing property damage, personal injury, or death. Do not over tighten screws. If a fastener connection is stripped, contact the manufacturer listed on the water heater rating plate. Step 1.
Pressure Switch Testing Pressure Switch Testing & Replacement Step 1. position. Move the gas control power switch to the “OFF” Gas control power switch Step 2. Unplug the water heater from the wall outlet. Blower (water heater) power cord Step 3. Unplug the cord sets from the blower. Cord sets Slotted screwdriver Step 4. Using a slotted screwdriver, remove the (3) screws (one on the backside of the junction box is not shown) holding the end of the blower junction box on.
Pressure Switch Testing Pressure Switch Testing & Replacement (cont’d) Step 7. Using a slotted screwdriver, remove the (2) screws holding the pressure to the blower junction box. Retain the screws for later use. Pressure switch screws Step 8. Pull the pressure switch out of the junction box. Pressure switch Step 9. Using a multi-meter, check the resistance across the pressure switch terminals. There should be no electrical continuity, meaning the switch is open. Multi-meter leads Step 10.
Arrestor Cleaning Pressure Switch Testing & Replacement (cont’d) Step 21. To resume operation, follow the instructions located on the water heater lighting instruction label. Or, use the lighting instructions located in the water heater installation and operating manual. ScreenLok® Flame Arrestor Cleaning Procedure Step 1. Move the gas control power switch to the “OFF” position and unplug the water heater from the wall outlet. Step 2. Remove the outer door. Step 3.
Common Terms Common Terms BTU ECO GPM Hz KWh LED NPT Ohms PSI RPM VAC W.C.
Parts List PART NAME AND DESCRIPTION 1. DraŌ Hood 15. Inner Door (Right) 2. Jacket Head Pan 15A. ReseƩable Thermal Switch 3. Jacket 16. Inner Door (LeŌ) 4. Blower 17. Blower Wire Harness 5. Heat Trap—Outlet 18. Feedline 6. Magnesium Anode–Hot Water Outlet 19. Gas Control Valve 7. Heat Trap—Inlet 20. Wire Harness (FVS / RTS) 8. Flue Baŋe Assembly 21. FVS Sensor Clip 9. Dip Tube–Cold Water Inlet 22. Flammable Vapor Sensor (FVS) 10. Temperature and Pressure Relief Valve 23. Outer Door 11.
