Bosch 940 ESO Installation Manual

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6 720 644 95646GWH 940 ESO Functional scheme14 GWH 940 ESO Functional schemeFig. 64 Functional schemeFan speedOK?waitingtime of 10spassed?water tapopen?Water flow0.5 gpm(> 1.9 l/min)(see WF calc.)> NONONONOYESYESYESYESNO NO NONOYES YESStart sparkingIDLEOpen the gasvalve1stSafety timeof 5s passed?Ionizationdetected?6720608158-65.2VNONONONOYESYESYESSee errorcode tablePost purge offan for 7 sec.Stay blockedtill RESETclose secondgas valvePost purge offan for 7 sec.water tapclosed<0.5 gpm?safetydevicesOK?close one gasvalve waitingtime of1s passed?flame off?Hot waterdelivered atselected temp.Applianceready to start?Fan speed = correctIonization = offTemp. limiter = closedTemp. sensors = okOver heat protection = okSee error code tableINPUTS:- FANSPEED- WATER TEMP.- WATERFLOWOUTPUTS:- FANSPEED- WATERFLOWYESYESYES YES2ndSafety time of5s passed?3rdSafety timeof 5s passed?Water flowCalculusWF =Burner ON Burner ONMinimum Power(Set point - Inlet)NOYES YESBurner shutdown at:Set point +9°F (5°C)WF < 0.45 gpm ± 0.05 gpm(WF < 1.7 l/min ± 0.2 l/min)Burner shutdown at:Set point +14°F (8°C)WF < 0.45 gpm ± 0.05 gpm(WF < 1.7 l/min ± 0.2 l/min)0.5 GPM < WF < 1.6 GPM(2 l/min < WF <6 l/min) WF > 1.6 GPM(WF > 6 l/min)NOWater flow procedure