EcoStor2™ Solar Gas Water Heaters SERVICE MANUAL SUPPLEMENT Troubleshooting Guide and Instructions for Service (To be performed ONLY by qualified service providers) Models Covered by This Manual: SDW2504T*F(BN,SX) SDW265T*F(BN,SX) SDW275S*(BN,SX) SDW2TW50T*F(BN,SX) SDW2TW65T*F(BN,SX) SDW2TW75T*(BN,SX) (*) Denotes Warranty Years SDW275S6BN shown above Manual 238-48244-00A 11/09 Save this manual for future reference
The Bradford White EcoStor2™ Solar Gas Water Heaters Table of Contents How to use this manual Service Procedure --- Introduction 4 --- Thermistor Wiring 5 --- Thermistor Wiring Test Procedure 6 ST-I Gas Control Temperature Sensor 7 --- Temperature Sensor and Harness Testing 8 ST-II Temperature Sensor Measurement 9 ST-III Solar Thermal Troubleshooting 10 --- Solar Thermal Parts List (Atmospheric) 11 --- Solar Thermal Parts List (Ultra Low NOx) 12 --- Solar Thermal Parts List (TT
EcoStor2™ Solar 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 EcoStor2™ Solar with Gas Backup Water Heaters. Understanding the solar thermal sequence of operation section of this manual will contribute greatly to troubleshooting the water heater. This manual serves as a water heater supplement to service and troubleshoot specifically the solar features of the water heater.
EcoStor2™ Solar Introduction The Bradford White EcoStor2 Solar Water Heater System The new Bradford White Solar with Gas Backup water heaters are designed to provide reliable performance with enhanced standard features.
EcoStor2™ Solar Thermistor Wiring This section is intended to provide a better understanding of the solar thermal design application and how it varies from the base model listed on page 3. Solar Thermistor Wiring The solar with gas backup water heater comes provided with two sets of twisted thermistor wiring. They are color coded for ease of use. Brown and Orange twisted thermistor wires The solar with gas backup models come with an internal double-wall heat exchanger.
EcoStor2™ Solar ST-I Thermistor Wiring Test Procedure Thermistor Wire Testing Step 1. Disconnect and unplug the solar control. Step 2. Disconnect the thermistor twisted pair from the control or control sensor wiring. Step 3. Connect a multimeter set to read ohms to the twisted wire stripped ends. Determine the resistance value of the attached thermistor. NOTE: The thermistor is field supplied and various thermistors have different ohm values for different temperatures.
EcoStor2™ Solar Gas Control Temperature Sensor The solar with gas backup water heater senses temperature from the upper portion of the tank. This allows the solar thermal heating system to maximize the ability to heat the water inside the tank. Only when the upper portion of the water heater tank reaches the water temperature to turn on the gas control, does the backup heat begin.
ST-II EcoStor2™ Solar If the control has gone into lockout due to excessive tank temperature (four flash, 3 second pause) reset the control by rotating the gas control knob to “OFF” position. Then follow the lighting instructions and return the gas control knob to the desired setpoint. Temperature Sensor and Harness Testing Disconnect thermal well wire harness Observe the water heater operation.
EcoStor2™ Solar ST-III Temperature Sensor Measurement WARNING Stored water may be HOT when performing the following steps in this procedure. Take necessary precaution to prevent personal injury. DETERMINE THE WATER TEMPERATURE INSIDE THE STORAGE TANK NOTICE It is important to understand once the resistance for the temperature sensor is determined from the previous page, water flow through the water heater should not occur.
EcoStor2™ Solar Solar Thermal Troubleshooting Chart This troubleshooting chart serves as a water heater supplement to troubleshoot specifically the solar features of the water heater. Please refer to page 3 to determine which base model service manual is appropriate for the non-solar troubleshooting chart for the water heater. SYMPTOM PROBABLE CAUSE Not enough hot water 1. Gas control temperature sensor out of spec. 2. Improperly sized solar collector(s). 3. Gas backup not functioning. 4.
EcoStor2™ Solar Solar Thermal Parts List (Atmospheric) 1 29 Draft Hood 2 Hex Head Anode Aluminum 3 Heat Trap Insert 4 Hot Water Outlet Anode Aluminum 5 Cold Water Inlet Polysulfone (NC Code) 6 Flue Baffle Complete 7 Junction Box Cover 8 Conduit Cover/Ground 9 T&P Relief Valve 10 Thermostat Bracket Assembly 11 Access Cover 12 Outer Door 13 Screw-#6-20 x 3/8 PHCR 14 Nat. Gas Resettable Thermal Switch 15 Nat.
EcoStor2™ Solar 25 Inner Door Gasket Kit 26 ASSE Approved Mixing Valve (Optional) 27 Universal Integrated Mixing Device Kit (IMD) 28 Burner Assembly Solar Thermal Parts List (Ultra Low NOx) 29 Manifold Mount 30 Orifice 31 Flexible Gas Feedline 32 Resettable Thermal Switch 36 Pilot Orifice 33 Burner 37 Thermopile Kit 34 Pilot Assembly Kit 38 Thermostat Sensor Wire Harness 35 Screw-#8-18 X 1/2 TEK 39 Solar Sensor Wire Harness 12 12 1 Draft Diverter 2 Hex Head Anode (Aluminu
EcoStor2™ Solar 34 Inner Door Gasket Kit 39 Burner Assembly Complete 35 ASSE Approved Mixing Valve (Optional) 40 Burner 36 Universal Integrated Mixing Device Kit (IMD) 41 Main Burner Orifice 37 Thermostat Sensor Wire Harness 42 Pilot Assembly 38 Solar Sensor Wire Harness 43 Pilot Orifice Solar Thermal Parts List (TTW) 1 Blower Complete 2 Air Mixing Inlet 3 Pressure Switch 4 Blower Temperature Switch 5 Blower Gasket 6 Blower Power Cord 7 3" Exhaust Adaptor w/Vent Terminal 8
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