A.O. Smith BFM - 100, BFM - 120 manual Troubleshooting No hot water

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11.4 Troubleshooting: No hot water
No hot water

Symptom	Cause	Solution			Remark

No attempt to start	No supply voltage	1.	Check if the isolator is ON.		See the BFM electrical diagram (14 "Electrical diagram")
heating cycle	present	2.	Check whether there is power to the isolator		If the error cannot be rectified, contact your installation engineer
		2.	Check whether there is power to the isolator
		3.	Check whether there is power to the electrical connector block
		4.	Check whether there is power to the burner control
		5.	Check fuse in the burner control
		The measured voltage must be 230 VAC (-15%, +10%).

No attempt to start	Pressure switch not	1.	Blockage in the chimney flue or air supply		Once the error is rectified, the appliance will automatically start up
heating cycle (blocking	closing		-	Trace the blockage	if there is a heat demand
error)			-	Trace the blockage	If the error cannot be resolved or is persistent, contact your
error)			-	Remove the blockage
			-	Remove the blockage	installation engineer
		2.	Defective pressure switch
			- Check the wiring of the pressure switch
			- Check that the pressure switch is working

	Failure in the	1.	Check whether the control thermostat is switched (closed)
	thermostat circuit	2.	Check leads and sensors of the control and high-limit
		2.	Check leads and sensors of the control and high-limit
			thermostats

Repetitive starting of	Too much resistance in	1.	Check whether the chimney flue configuration (3.9 "Air supply		If the error cannot be resolved or is persistent, contact your
the heating cycle	the chimney flue (the		and flue") has been installed in accordance with instructions		installation engineer
(cycling of the	pressure switch opens
appliance)	during heating)

Instruction manual BFM

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Contents Page Page Read this manual carefully TrademarksLiability More informationGis Table of contents Troubleshooting Performing maintenanceWarranty certificate Electrical diagramIntroduction About the applianceWhat to do if you smell gas Regulations Maintenance Forms of notation Target groups Symbol Target groupIntroduction Overview of this DocumentChapter Target groups Description Gis Working principle of the appliance General workingPrinciple Appliance Working principle of the appliance Appliances heating cycle Protection for the appliance Water temperature protection Pressure switchFlame probe Protection DescriptionSafety of the instal- lation Unvented installationVented installation 3 T&P valveGis Installation Air humidity and ambient temperatureAir humidity and ambient temperature PackagingInstallation Maximum floor loadWater composition Working clearancesTechnical specifica- tions Dimensions of the appliance Plan and elevation of the applianceGeneral and electrical specifications Dimens DescriptionBFM100 BFM120 Ion UnitGas data Description UnitNatural gas G20 20 mbar LP gas data G30 30 mbar butaneInstallation diagram Installation diagramWater connections, Vented Cold water sideRecirculation pipe Hot water sideSee C in the installation diagram 3.5 Installation diagram Circulation pipe Water connections, UnventedCirculation pipe Gas connectionInstalling chimney flue components for BFM 30, 50 Air supply and flue IntroductionConcentric wall flue terminal BFM Subject DescriptionConcentric roof flue terminal BFM 30, 50 C33 concentric roof flue terminal specifications BFM 30, 50 Installing chimney flue components for BFM 100Concentric wall flue terminal BFM100 C13 concentric wall flue terminal specifications BFM 100 M2000 MDV SCCConcentric roof flue terminal BFM 100 11 C33 concentric roof flue terminal specifications BFM 100 Electrical connectionConnecting the mains power Mains power Fan Alarm OffChecking the supply pressure and burner pressure Gas control for BFM 30 throughGas control for BFM BFM 30, 50, 80 BFMConversion to a different gas category ConversionOrifice replacement Conversion to a different gas categoryPage Conversion to a different gas category Filling Filling Draining Draining unvented installations DrainingDraining vented installations Gis ON/OFF switch Control panelExplanation of icons Control thermostatBurner control reset button Control panelError conditions Status of the applianceOperating modes Status of the appliance Starting and running Starting the applianceAppliances heating cycle Starting and running Shutting down the appliance for a brief period OFF mode Shutting downIsolating the appliance from the mains Shutting the appliance down for a long periodShutting down Troubleshooting Control thermostat 7.5 Control thermostatTroubleshooting general errors Symptom Cause Solution Remark Gas smellWater leakage Explosive ignitionTroubleshooting insufficient hot water Symptom Cause Solution Remark Insufficient hot waterTroubleshooting No hot water Symptom Cause Solution Remark CyclePage Performing maintenance Introduction Preparation for maintenanceDescaling and cleaning the tank Performing maintenanceWater-side mainte- nance 12.3.1 Checking the anodesIMD-0235 R2 Clean the burners Clean the orificesGas-side mainte- nance 12.4.1 Checking the flue baffles Finalising mainte- nanceWarranty certificate 13.1 General warranty13.2 Tank warranty Conditions for Instal- lation and useWarranty certificate Electrical diagram BFM Electrical Diagram Electrical diagramOptional Components Electrical diagram Index 0306 Index