A.O. Smith BTR 151 THRU 201/A warranty High Limit Switch, Exhaust Inducer Blower Assembly

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possibility of changing the orientation by accidentally overtightening the inlet supply. Improper orientation of the Eliminator may cause temperature buildup issues or spells of colder than usual water temperatures.

HIGH LIMIT SWITCH

The digital thermostat (see Figure 3) contains the high limit (energy cutoff) sensor. The high limit switch interrupts main burner gas flow should the water temperature reach 203°F(195°C).

In the event of high limit switch operation, the appliance cannot be restarted unless the water temperature is reduced to approximately 120°F (49°C). The high limit reset button on the front of the control then needs to be depressed.

Continued manual resetting of high limit control, preceded by higher than usual water temperature is evidence of high limit switch operation. The following is a possible reason for high limit switch operation.

A malfunction in the thermostatic controls would allow the gas valve to remain open causing water temperature to exceed the thermostat setting. The water temperature would continue to rise until high limit switch operation.

Contact your dealer or service agent if continued high limit switch operation occurs.

EXHAUST INDUCER (BLOWER ASSEMBLY)

All units are equipped with a exhaust inducer. The inducer assists in drawing in fresh air to the unit for combustion and then assists in dispensing the combustion by-products into the venting leading outside.

The exhaust inducer is equipped with a gravity controlled damper to reduce the amount of heat loss through the flue, improving efficiency.

FIGURE 5 - EXHAUST INDUCER

FIGURE 3 - DIGITAL THERMOSTAT

ELECTRONIC IGNITION CONTROL

Each heater is equipped with a ignition module. The solid state ignition control (see Figure 4), ignites the main burner by utilizing a silicone nitride ignitor. The silicone nitride ignitor shuts off during the heating cycle and the main burner flame is sensed through a remote flame sensor integral to the silicone nitride ignitor assembly. The ignition control will try to ignite the main burner three times before lockout. Then it waits one hour before trying again to ignite the main burners. This is a continuous cycle.

FIGURE 4 - IGNITION CONTROL BOARD

CIRCULATING PUMP

A circulating pump is used when a system requires a circulating loop or there is a storage tank used in conjunction with the heater. Refer to the piping diagrams at rear of manual for electrical hookup information and install in accordance with the latest version of the National Electric Code ANSI/NFPA No. 70.

Only all bronze circulators are used with commercial water heaters.

Although circulators are oiled and operated by the manufacturer some circulators must be oiled again before operating. Please refer to manufacturer’s instructions.

DISHWASHING MACHINE REQUIREMENT

These appliances meet the National Sanitation Foundation Standard for sanitary installations when used with the following leg kits, Part No’s. 6570-0 and 6570-7.

All dishwashing machines meeting the National Sanitation Foundation requirements are designed to operate with water flow pressures between 15 and 25 psi. Flow pressures above 25 psi, or below 15 psi, will result in improperly sanitized dishes. Where pressures are high, a water pressure reducing or flow regulating control valve should be used in 180°F (82°C) line to the dishwashing machine, and should be adjusted to deliver water between these limits.

The National Sanitation Foundation also recommends circulation of 180°F (82°C) water. Where this is done, the circulation should be very gentle so that it does not cause any unnecessary turbulence inside the water heater. The circulation should be just enough to provide 180°F (82°C) water at the point of take-off to the dishwashing machine. Adjust flow by means of the plug cock in the circulating line.

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Contents Division of A. O. Smith Corporation PlacetheseinstructionsadjacenttoheaterAndnotifyownertokeepforfuturereference Recovery Rating Capacities GPH AT Temperature Rise Shown ROUGH-IN-DIMENSIONSForeword Heater Performance DataTable of Contents High Altitude Installations FeaturesExtended NON-USE Periods Insulation BlanketsExhaust Inducer Blower Assembly High Limit SwitchElectronic Ignition Control Circulating PumpUncrating Required AbilityLocating the Heater LevelingConfinedspace VentingTo the Heater and Risk of Fire or Explosion Unconfinedspace Water Line Connections Multiple Heater ManifoldWater Potable Heating Space Heating Relief ValvePurging GAS PipingGAS Pressure Regulator Length Nominal Iron Pipe Sizes Inches FeetSingle Unit Wiring Diagram Heater WiringGeneral Installation DiagramsHorizontal Storage Tank and Forced Circulation Vertical Storage Tank and Forced CirculationPage Circulating Return Line Connection Installation DIAGRAMS-SIDE INLET/OUTLET UsageHeater with Mixing Valve and Recirculated Sanitizing Loop TWO PRE-HEATERS with Booster Heater Horizontal Storage Tank Sequence of Operation OperationWhat to do if YOU Smell GAS For Your Safety Read Before OperatingWater Temperature Control Preventive MaintenanceCheck the Ignitor Assembly Ignitor AssemblyGAS Valves Remote Storage Tank Temperature ControlChecking the Input Venting SystemAnode ROD Inspection HOT Water OdorFlushing DrainingDeliming Solvents Tank Cleanout ProcedureDeliming Using FLO-JUG Method Replacement Parts ServiceSystem Diagnostics Ignition Module SystemYES Sequence of Operation Flow ChartRemedy Operational ChecklistComplaint Cause User Serviceman Claimprocedure ServiceandrepairexpensesKeepthiswarrantypostedadjacenttotheheaterforfuturereference TankSmith Water Products Company