540 T-H3 Service Manual Brandname: A.O. Smith Category: Water Heater Total Pages: 104 Table of contents TableofContents21Specifications32ExteriorView43InteriorView65SchematicDiagram136WiringDiagram149OperationalFlowChart2010ComponentSpecifications2110-1Burners2210-2GasManifold2310-3FanMotor2410-4GasValveAssembly2510-5FlameRod2610-6AfrRod2710-7HeatExchanger2810-7HeatExchanger2910-9FlowAdjustmentValve3210-10FlowSensor3310-12Thermistors3510-12Thermistors3610-13ExhaustThermistor3710-14Hi-LimitSwitch3810-14Hi-LimitSwitch3910-16OverheatCutOffFuse4110-18ComputerBoard4310-19Igniter4410-21SurgeBox46