A.O. Smith 300A, 500A warranty Operating Instructions, Prior to Start UP Required Ability

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PRIOR TO START UP - REQUIRED ABILITY

INSTALLATION OR SERVICE OF THIS WATER HEATER REQUIRES ABILITY EQUIVALENT TO THAT OF A LICENSED TRADESMAN IN THE FIELD INVOLVED. PLUMBING, AIR SUPPLY, VENTING, GAS SUPPLY AND ELECTRICAL WORK ARE REQUIRED.

Before attempting start-up, thoroughly study and familiarize yourself with the exact sequence of operation and all other details on the specific heater being used.

The power burner is equipped with an ignition system which automatically sequences prepurge and ignition, senses and ignites main burner flame and sequences burner operation. Heater is equipped with an ignition control which locks out after three unsuccessful ignition attempts. Familiarize yourself with the sequence of operation of this unit prior to start-up.

Be certain that the water heater is full of water, that air is purged from all lines, there are no leaks (gas and water), and all inlet water lines are open.

The following test equipment should be on hand (all test equipment must be acclimated to ambient temperature before calibration and use.)

– Two U-tube manometers or calibration 0-10" W.C. (0-2.5Kpa) and 0-35" W.C. (0-8.7Kpa) pressure gauges.

Attach a gas pressure gauge or manometer to the upstream side of main gas cock and a gas pressure gauge or manometer to the manifold pressure tap.

You are now ready to begin the burner start-up procedure.

OPERATING INSTRUCTIONS

IMPORTANT

IT IS RECOMMENDED THAT A QUALIFIED SERVICE TECHNICIAN

PERFORM THE INITIAL FIRING OF THE HEATER. AT THIS TIME THE

USER SHOULD ASK THE TECHNICIAN ANY QUESTIONS IN REGARD TO THE OPERATION AND MAINTENANCE OF THE UNIT.

CAUTION

BEFORE PROCEEDING WITH THE OPERATION OF THE UNIT, MAKE SURE HEATER AND SYSTEM ARE FILLED WITH WATER

AND ALL AIR IS EXPELLED FROM HEATER AND PIPING.

NEVER OPERATE THE HEATER WITHOUT FIRST BEING CERTAIN IT IS FILLED WITH WATER AND A TEMPERATURE AND

APRESSURE RELIEF VALVE IS INSTALLED IN THE RELIEF VALVE OPENING OF THE HEATER. DO NOT ATTEMPT TO OPERATE

HEATER WITH COLD WATER INLET VALVE CLOSED.

FILLING:

1.Close the heater drain valve.

2.Open a nearby hot water faucet to permit the air in the system to escape.

3.Fully open the cold water inlet pipe valve allowing the heater and piping to be filled.

4.Close the hot water faucet as water starts to flow.

5.The heater is ready to be operated.

THEMAINMANUALGASSHUTOFFVALVEMUSTHAVEBEENCLOSED FOR AT LEAST FIVE (5) MINUTES. THIS WAITING PERIOD IS AN

IMPORTANT SAFETY STEP. ITS PURPOSE IS TO PERMIT GAS THAT

MIGHT HAVE ACCUMULATED IN THE COMBUSTION CHAMBER TO CLEAR. IF YOU DETECT GASATTHE END OF THIS PERIOD, DO NOT PROCEED WITH LIGHTING. RECOGNIZE THAT GAS ODOR, EVEN IF ITSEEMSWEAK,MAYINDICATETHEPRESENCEOFACCUMULATED GASSOMEPLACEINTHEAREAWITHARISKOFFIREOREXPLOSION.

SEE THE FRONT PAGE FOR STEPS TO BE TAKEN.

DO NOT USE THIS HEATER IF ANY PART HAS BEEN UNDER

WATER. IMMEDIATELY CALL A QUALIFIED SERVICE TECHNICIAN TO INSPECT THE HEATER AND TO REPLACE ANY PART OF THE CONTROL SYSTEM AND ANY GAS CONTROL WHICH HAS BEEN UNDER WATER.

LIGHT THE UNIT IN ACCORDANCE WITH THE OPERATING INSTRUCTIONS LABEL ATTACHED TO THE HEATER.

THESE INSTRUCTIONS ARE REPEATED IN THE LIGHTING AND

OPERATING LABEL ILLUSTRATION IN THIS MANUAL.

ADJUSTMENT PROCEDURE - Initial Start-up

A minimum dynamic gas supply pressure of 5.2" W.C. (1.29 kPa) for Natural Gas and 11" W.C. (2.74 kPa) for LP Gas is required before making any adjustment to the gas control pressure regulator Attempts to adjust the regulator during periods of low gas supply pressure could result in overfiring of the heater when the gas supply pressure returns to normal.

1.Check gas line pressure with a manometer, adjust the gas supply line pressure per table 4.

2.Check manifold pressure (see Table 4) using a pressure gauge (manometer) connected to the manifold pressure tap on the gas control valve, (Figure 15).

If full rate adjustment is required, remove cover screw from top of the gas control valve, (Figure 15).

Using a small screwdriver, turn adjusting screw clockwise to

increase or counterclockwise to decrease gas pressure to obtain 4.0" W.C. (0.996 kPa) for Natural Gas and 10" W.C. (2.49 kPa) for LP gas.

3.Cycle the burner on and off several times to check its operation.

4.Check the operation of the limit and operating controls.

5.Check the vent system seams and joints and ensure that there is no discharge of flue products into the room.

6.Check the input rate:

For appliance installation locations with elevations above 10,000 feet (3,048 m) refer to HIGH ALTITUDE INSTALLATIONS section of this manual.

a.Attach a pressure gauge (manometer) to the manifold pressure tap (Figure 16) and refer to Table 4 for correct pressure.

b.Use this formula to “clock” the meter. Be sure other gas consuming appliances are not operating during this interval.

3600

X H = Btuh

3600 X 1050 = 300,000 Btuh (87.9 kW)

T

 

12.6

T = Time in seconds to burn 1 cubic foot of gas. (With a stopwatch read the gas meter and measure the amount of time required for the heater to consume 1 cubic foot of gas.)

H = Heating value of gas (in Btu’s per cubic foot of gas). Btuh = Actual heater input rate, in Btuh.

EXAMPLE: (Using BTH-300 heater) T = 12.6 seconds

H = 1050 Btu/ft.3

BTUH = ?

For high altitude installations, compare result to the derated input required for the elevation at the installation location.

Should it be necessary to adjust the gas pressure to the burner, to obtain the full input rate, the steps below should be followed:

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Contents Cyclone Xi Model BTH 300A, 400A, 500A Foreword ROUGH-IN-DIMENSIONSFeatures Table of ContentsHorizontal Sidewall Venting Vertical Rooftop Venting Quick Installation TipsHigh Limit Switch E.C.O Water Temperature Setpoint Adjustment ProcedureDishwashing Machine Requirement Circulating Pump Installation InstructionsRequired Ability Insulation BlanketsHard Water ClearancesAIR Requirements Unconfined SpaceVenting Installation of Carbon Monoxide DetectorsCanadian Direct Vent US Horizontal Vent Vent Pipe Termination Direct Vent Terminal InstallationDirect Venting Vertical Vent Terminal Installation Installation SequenceVent Length Table Installation of Vent SystemControls and Switches HOT Surface Igniter GAS PipingConnection of GAS Pipe System Connections Water Potable Heating and Space Heating Heater WiringBTH 300 Wiring Diagram BTH 400 and 500 Wiring Diagram Electronic Control OperationSequence of Operation OverviewAdjusting the Operating Set Point Changing the Display Units Fault and Warning ConditionsExample of a Warning Access to the Current Fault or Warning Example of a Fault Advanced Diagnostics InformationViewing Information About the Heater Viewing the Fault HistoryPrior to Start UP Required Ability Operating InstructionsOperating Instructions General Information MaintenanceDraining FlushingSediment Removal Lime Scale RemovalDrain Valve and Access Panels Powered Anode SystemVent System U T I O N if Building Installation DiagramsPage Must be Identical Heaters Pipe Relief Valve to Open Drain Page Multiple Unit Installations Troubleshooting Motor RUNS, Burner Lights Momentarily Then Locks OUT Motor will not RUNNoisy Burner Operation Replacement PartsGAS Fails to Shut OFF Model BTH Limited Warranty