Installation, Operation, And Service Instructions 21WHTBLUWHTREDBLKORNOILPREHEATER BLOCKCONTROLLERWHTRED HTRPRIL2L1BLOWER MOTORWHTHIGHVOLTAGETRANS-FORMER BLKPHOTO EYEFLAME SENSOROIL PRIMARY CONTROL(IE, Honeywell, etc.)BLKORNWHTTHERMOSTATCONNECTION500WHEATRODBiMETALHIGHLIMITSWITCHTHERMO-COUPLEOILPREHEATERBLOCKFusePower SwitchBLKBLKWHTWHTREDWHTWHTWHTREDBLUREDPower Plug(Looking at Terminal Side)BLKOil ValveBLKGRNPower SocketElectrical Box(Looking at Socket Side)Burner AssemblyThermostatCirculatorHoneywellL8148A AquastatT T L1 L23B1 B2C2C1JumperNHOil PumpWHTBLKWHTBLKService SwitchFused Disconnect SwitchHNGND(Items Supplied By Installer)120 VAC(Supplied By Installer)LowWaterCutoffManualHighLimitL4006EREDWHTFigure 33. WIRING DIAGRAM, SINGLE HEATING ZONE ONLY, OWB-90, OWB-150, OWB-350