A.O. Smith TC-049-R2 Circuit, Operation From cold tank of water, Elements Thermostats High Limit

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RESIDENTIAL GAS AND ELECTRIC WATER HEATER

SERVICE HANDBOOK

Residential Electric – continued

A-6 Circuit

•2 Elements

•2 Thermostats

•1 High Limit

Operation: From cold tank of water

A-6 CIRCUIT

Power Enters High-Limit

Through High Limit

Upper Thermostat

1, 4 Contacts Open

Power Interrupted to Upper Element Upper Thermostat, 1, 2 Open

1, 2 Contacts Closed

Power to Upper Element

Element Heats Water

Upper Thermostat Satisfied

Switch Power to Lower Thermostat – Upper Thermostat, 1, 4 Closed

Lower Thermostat

Contacts Open

Lower Thermostat Contacts Closed

Power to Lower Element

Element Heats

Water

Lower

Thermostat

Satisfied Lower 1, 2 open

Power Interrupted to Lower Element

	A.O. Smith Water Products Company	23	Training Department
	©2002		Ashland City, Tennessee

Image 24

Contents Smith Service Handbook Table of Contents Residential GAS and Electric Water HeaterQualifications Tools Required General Section Service Guidelines FormulasMiscellaneous Information Construction General SectionInstallation of Residential GAS Water Heater Lighting PilotResidental GAS Water Heater Service Construction See also General section of this manualNormal Operation Residential GasService Handbook Setting Approximate Temperature F Time To Cause Injury 000 FuelEnters Here BTUIf … … then ManifoldPilot Gas Gas PressureElectrical Testing Thermocouple output test Procedures/ConditionsSooting causes If … … then Procedures Residential Gas Electrical TestingIf… … then CondensationCondensation is a mild acid it will corrode steel Exhaust Venting Notes 125 Standard Residential Electric Water Heaters Construction Heating elementsVoltage Notes Residential Electric Newer Temperature Surface Mounted Thermostat s and High Limit s Location Range F Service Handbook Wiring Diagram Normal Sequence of OperationSingle Element Single Thermostat Single High Limit Circuit Operation From cold tank of waterElements Thermostats High Limit Wiring Diagram Operation From cold tank of waterElements Thermostats High Limits Wire Service Handbook Post Cold tank of water Single Electrical Service Single Phase Certification and Approvals Three Phase Unbalanced Circuit WattageElement Test Ohms Resistance Check Test Conditions Test probe on each terminal of an elementProcedure Residential Electric ServiceComplaint No Hot Water Conditions Test voltage between 4 and 2 or T2 and L4 If … … thenResidential Electric Service No Hot Water Test between the two element terminals If … … thenComplaint Water Too Hot Conditions Voltage Check Test between 4 and 2 or L4 and T2 If … … thenTest around red wire then black wire to element If … … then Residential Electric Service Water Too HotGrounded Element Check Amperage Method Circuit Servicing Testing with the Multimeter Complaint No hot water Test ConditionsVoltage Check Test between 1 and 3 or L1 and L3 If … … thenResidential Electric Service Voltage Check No Hot Water Complaint Lack of Hot Water ConditionsTest between high limit 4 and lower thermostat 1 or L4 Test between high limit 4 and lower thermostat 2 or L4Service Handbook Testing The A-7 Wiring Circuit Supply wiring may be a See Pages 25Prior To Post Test probe on each terminal of an element If … … then Power on Voltage ChecksTest between upper high limit terminals 1 If … … then Test between upper high limit terminals 2Complaint Lack of Hot Water Test Conditions Test between lower high limit terminal 1 and 3 or L1 and L3Test Condition Test between the terminals of the lower element If … … thenPower on Thermostats are satisfied Replacement elements Watts divided by Volts = AmpsVolts times Amps = Watts Service Handbook Smith Technical Bulletins WHY Water Heater Tanks Leak What Prevention WHY Water Heater Tanks Leak What WHY PreventionWater Conditions Water Hammer GeneralEffects FIXSymptoms Mineral BUILD-UPCause Aluminum Hydroxide If tank is new with no lime build-up to any degreeDiscolored Water TreatmentSmelly Water Chlorination Procedure ProcedureNot Enough HOT Water GAS TestNot Enough HOT Water Electric Thermal Expansion Follow these easy steps to diagnose thermal expansionService Handbook Leaking Temperature and Pressure Relief Valve For every technical problem There is a solution