A.O. Smith BFC -100, BFC - 80 service manual Appliances heating cycle Protection for the appliance

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2

Working principle of the appliance

gis

2.3The appliance's heating cycle

2.4Protection for the appliance

2.4.1

The appliance is equipped with a gas/air premix burner (17). The air is drawn in through the fan (18). The gas is supplied via the gas control (16) on the intake side of the fan. The gas/air mixture is then blown into the burner. The modulated supply of gas and air ensures that the optimum gas/air mixture is always achieved.

In this appliance the cold water enters the bottom of the tank via the cold water inlet (14). Once heated by the combustion chamber (8) and heat exchanger (11), the hot tapwater leaves the tank through the hot water outlet (2). Once the appliance is completely filled with water, it remains constantly under water supply pressure. As hot water is drawn from the appliance, it is immediately replenished with cold water.

The air required for combustion is forced into the burner (17) by the fan (18).

The gas is fed to the burner via the gas valve (16). Thanks to the modulated supply of gas and air, the optimum gas/air mixture is always achieved. The special construction of the burner causes the mixture to form a vortex (the cyclone effect), before it becomes ignited. This vorticity improves the ignition on the hot surface igniter (20), as well as ensuring optimum combustion efficiency. Through the special design of the heat exchanger (11), the flue gases are first led downwards via the combustion chamber, then upwards again via the heat exchanger, then once more downwards beside the water in the tank. In this process, the flue gases gradually become cooler. Because the cooled flue gases flow alongside the cold water lower down in the tank, they start to condense. This condensation causes latent heat energy to be released, which is transferred to the cooler water, thereby increasing the energy performance of the unit. The condensate yielded by this process is discharged via the siphon (23).

The insulation layer (24) prevents heat from escaping. The inside of the tank is enamelled to protect against corrosion. The anodes (9) provide extra protection against corrosion.

For use during maintenance, the appliance has an inspection and cleaning opening (12).

<The entire appliance is controlled (and monitored) by the ThermoControl (electronic controller).The water temperature is measured by temperature sensors T1 (7) in the top of the tank (10) and T2 (13) at the bottom of the tank. These temperatures are sent to the electronic controller. Based on these two observations, the electronic controller calculates a net water temperature: Tnet. The value of Tnet lies between the temperatures at the top and bottom of the tank. As soon as Tnet falls below the set water temperature (Tset), the electronic controller registers a "heat demand". The gas control (16) is opened, and the gas is mixed with air. This mixture is ignited by the hot surface igniter (20) and the water becomes heated. As soon as Tnet rises above Tset the heat demand ends, and the electronic controller stops the heating cycle.

The electronic controller assumes a certain margin both when registering and ending heat demand. We refer to this margin as the hysteresis (12.2 "Setting the hysteresis").

Introduction

The electronic controller monitors the water temperature and ensures safe combustion. This is achieved by:

•the Water temperature protection;

•theGas valve;

•the Fan;

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Instruction manual BFC

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Contents 100 Your installer Liability Read this manual carefullyTrademarks More informationGis Table of contents Maintenance frequency Service programTroubleshooting Performing maintenanceAppendices Table of contents What to do if you smell gas Regulations IntroductionAbout the appliance Introduction Target groups Maintenance Forms of notationSymbol Target group Chapter Target groups Description Overview of thisDocument Gis Working principle of the appliance General working principle of the applianceWorking principle of the appliance Water temperature protection TheGas valveAppliances heating cycle Protection for the appliance Gas valve Water temperature protectionPressure switch 4 FanVented installation Safety of the installationUnvented installation Flame probeEnvironmental InstallationPackaging ConditionsWater composition Air humidity and ambient temperatureMaximum floor load Working clearancesTechnical specifications Dimensions of the appliance Unit BFC General and electrical specificationsDimen Description BFC Sion Gas data Description II2H3P Unit BFC Natural gasInstallation diagram Hot water side Water connections, VentedCold water side Circulation pipeWater connections, Unvented Requirements for flue gas discharge materials Gas connectionAir supply and flue Introduction C43 B23 C33 C13 C53 Type of appliance Description Concentric connectionsPractical example of concentric flue gas discharge Appliance Diameter Maximum length Number BendsSpecifications Appliance with concentric flue gas discharge materialConcentric wall flue terminal specifications C13 Subject DescriptionParallel connections Practical example of parallel flue gas dischargePreparation Connecting the mains voltage Electrical connectionPreparation 10.2 Preparation Connecting the mains voltageIsolating transformer Connecting an extra error signal Alarm OUT Connecting a program-controlled pumpConnecting an extra on mode switch Tank on Checking the supply pressure and burner pressureProcedure to check pressures 11.1Gas data Finalising Adjusting the pressure11.3 Finish off 3.11.4 FinalisingOrifice assembly Conversion to a different gas categoryConversion to a different gas category Start 9 Starting and running the applianceInstallation diagram FillingFilling the appliance Filling unvented installationsFilling vented installations FillingDraining Draining Min Gis Controls Electronic controller ON/OFF switchControl panel Meaning of iconsPC connection Control panelOperating modes Operating modes Error conditions Service conditionStatus of the appliance Status of the appliance Error conditionsManual 13 Troubleshooting Menu 11 Main menu chapterService condition Manual 14 Maintenance frequencyGis Appliances heating cycle Open 3.5 Installation diagram the manual gas valveStarting and running Starting and running Appliances heating cycleStarting and running Electrically isolating the appliance Shut the appliance down for a brief period OFF modeShutting down Shutting the appliance down for a long periodShutting down Main menu Switching on the on modeSetting water temperature during on mode Notational convention for menu-related instructionsChanging the appliances standard week program Week program setting the switch- on timeStarting and stopping the week program Main menuWeek program setting the program- controlled pump Week program setting the switch- off timeWeek program setting the water temperature Adding times to a week programPump 11.6.4 Week program setting the program-controlled pump Deleting times from a week programProgramming an extra period Setting the switch-on timeExtra period Settings Setting menu languageSetting day and time Displaying appliance specificationsRelevant display appears Displaying the error history Service programSetting the hysteresis Setting the display contrast Switching the pump on or offSetting the service interval Setting the display backlight timeDisplayed errors TroubleshootingGeneral errors Display is off Troubleshooting table for general errorsSymptom Cause Solution Remark Gas smell Start the appliance up 9 Starting and runningHot water supply Symptom Cause Solution Remark Water leakageExplosive ignition Insufficient or absentDisplayed errors S14 blocking error Code + Description Cause Solution Remark S12 blocking errorS13 blocking error S15 blocking errorCode + Description Cause Solution Remark F02 lock out error Code + Description Cause Solution Remark Check the values 2.4.5 Pressure switchReplaced Appliance Code + Description Cause Solution Remark F03 lock out errorMaintenance 15.2 Preparation for maintenance. If there is FlueCode + Description Cause Solution Remark F04 lock out error F05 lock out errorF08 lock out error Code + Description Cause Solution Remark F06 lock out errorF07 lock out error F09 lock out errorCode + Description Cause Solution Remark F10 lock out error F11 blocking errorC04 blocking error Code + Description Cause Solution Remark C02 lock out errorC03 blocking error Selected applianceE04 lock-out error Code + Description Cause Solution Remark E01 blocking errorE03 lock-out error Maintenance frequency IntervalMaintenance frequency Performing maintenance Introduction Preparation for maintenancePerforming maintenance Checking the anodes Water-side maintenance IntroductionDescaling and cleaning the tank Clean the burners Cleaning condensation water dischargeGas-side maintenance Finalizing maintenance Introduction Clean the orifices16.2 Tank warranty Warranty certificate16.1 General warranty Conditions for Installation and useWarranty certificate Appendices Week program cardBFC Electrical Diagram AppendicesTerminal Block Connections Appendices Tset Pump Week program cardPeriod Example PeriodPage Index 0308 Index

BFC - 80, BFC -100 specifications

A.O. Smith is a renowned name in the water heater industry, and its BFC series, which includes the BFC-100 and BFC-80 models, exemplifies their commitment to innovation and efficiency. These units are designed to meet the demanding needs of both residential and commercial applications, providing reliable hot water solutions.

The A.O. Smith BFC-100 and BFC-80 are distinguished by their high capacity and robust design. The BFC-100 model boasts a capacity of 100 gallons, while the BFC-80 is ideal for those requiring 80 gallons. This makes them suitable for larger households or commercial establishments where hot water demand can be significant.

One of the primary features of these models is their advanced heating technology. Both units utilize a high-efficiency burner that ensures rapid heating and minimal energy consumption. This means users benefit from shorter wait times for hot water, reducing overall energy costs. The BFC series is also equipped with a special flame retention head that enhances combustion efficiency and prolongs the lifespan of the unit.

In terms of construction, the BFC-100 and BFC-80 models are built with high-quality materials that enhance durability and resistance to corrosion. The tanks are insulated with high-density foam, which improves energy retention and helps maintain water temperature for longer periods. This is crucial for conserving energy and minimizing heating costs.

Safety is a top priority for A.O. Smith, and the BFC series reflects this commitment. Each unit comes with a range of safety features, including a temperature and pressure relief valve that prevents overheating and excessive pressure buildup. Additionally, they are designed to meet strict industry standards, ensuring peace of mind for users.

Installation of both models is straightforward, with flexible venting options that accommodate various building layouts. Whether you are upgrading an existing water heating system or installing a new one, the BFC series is designed to integrate seamlessly.

In summary, the A.O. Smith BFC-100 and BFC-80 are excellent options for those seeking reliable, efficient, and durable water heating solutions. With their impressive capacity, advanced heating technology, robust construction, and safety features, these models stand out in the market and are sure to meet the hot water needs of any household or commercial space. Whether for residential use or in a business setting, A.O. Smith’s BFC series represents quality and innovation in hot water heating.
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