A.O. Smith BTH 120-250(A) Installation & Operating Instructions Manual Download Page 20

20

 

WARNING

UNDER NO CIRCUMSTANCES SHOULD THE INPUT EXCEED THE RATE
SHOWN ON THE HEATER RATING PLATE. OVERFIRING COULD RESULT
IN DAMAGE OR SOOTING OF THE HEATER.

CATHODIC PROTECTION

 

CAUTION

HYDROGEN GAS CAN BE PRODUCED IN A HOT WATER SYSTEM SERVED
BY THIS HEATER THAT HAS NOT BEEN USED FOR A LONG PERIOD OF
TIME (GENERALLY TWO WEEKS OR MORE). HYDROGEN GAS IS
EXTREMELY FLAMMABLE. 

 

To reduce the risk of injury under these

conditions, it is recommended that a hot water faucet be opened for several
minutes before using any electrical appliance connected to the hot water
system. If hydrogen is present, there will probably be an unusual sound
such as air escaping through the pipe as the water begins to flow. There
should be no smoking or open flame near the faucet at the time it is open.

PRECAUTIONS

I

F THE UNIT IS EXPOSED TO THE FOLLOWING, DO NOT OPERATE HEATER

UNTIL ALL CORRECTIVE STEPS HAVE BEEN MADE BY A QUALIFIED
SERVICEMAN.

1. FLOODING TO OR ABOVE THE LEVEL OF THE BURNER OR CONTROLS

2. EXTERNAL FIRING

3. DAMAGE

4. FIRING WITHOUT WATER

5. SOOTING

NEVER OPERATE THE HEATER WITHOUT FIRST BEING CERTAIN IT IS
FILLED WITH WATER AND A TEMPERATURE AND PRESSURE RELIEF
VALVE IS INSTALLED IN THE RELIEF VALVE OPENING OF THE HEATER.

SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL TO SHUT
OFF, TURN OFF THE MANUAL GAS CONTROL VALVE TO THE
APPLIANCE.

GENERAL INFORMATION

POWER BURNER

The initial start-up procedure of the unit is provided on page 18.

The sequence of operation of the unit is provided on page 15.

It is important to note that the controller has a reset button on the control
box, Figure 1. The reset button is a safety device and would not normally
be used.

HIGH LIMIT

The high limit (not adjustable) is factory set to cutout at 202°F (94°C). The
controller must be manually reset by depressing the reset button on front
of the control when water temperature drops to below 160°F (71°C).

HIGH ALTITUDE INSTALLATIONS

 

WARNING

BTH HEATERS ARE CERTIFIED FOR USE WITHOUT MODIFICATION FOR

ALTITUDES UP TO 6500 FEET.  INSTALLATIONS ABOVE 6500 FEET MAY

REQUIRE REPLACEMENT OF THE BURNER ORIFICE.  CALL THE

TECHNICAL CENTER @ (800) 527-1953 FOR REQUIREMENTS.

Some gas utility companies derate their gas for altitude, making it

unneccessary to install high altitude orifices.  Call the local gas or utlity

company to verify BTU content.

Due to the input rating reduction at high altitudes, the output rating of the

appliance is also reduced and should be compensated for in the sizing of

the equipment for applications.

MAINTENANCE

GENERAL

KEEP APPLIANCE AREA CLEAR AND FREE FROM COMBUSTIBLE

MATERIALS, GASOLINE AND OTHER FLAMMABLE VAPORS AND LIQUIDS.

(SEE WARNING ON PAGE 5, LOCATING THE HEATER).

Water heater maintenance includes periodic tank flushing and cleaning,

and removal of lime scale. The unit should be inspected and adjusted to

maintain proper combustion. Refer to the following table. A periodic inspection

of the venting system should be made. Where used, the water circulating

pump should be oiled.

MAINTENANCE SCHEDULE

Following are the instructions for performing some of the recommended

maintenance. Unit inspection and adjustment should be performed by a

competent technician.

COMPONENT

OPERATION

INTERVAL

REQUIRED

Tank

Sediment

Monthly

Flushing

Removal

Tank

Lime Scale

Semi

UN-LIME

®

Removal

Annually

Delimer

Anode

Inspect

Semi

Replace as

Rods

Annually

Required

Relief Valve

Inspect

Semi

Annually

SAE No. 20

Circulating

Oiling

Four Months non-detergent

Pump (1)

motor oil

Clean Inlet

Blower

Screen and

As Required

Soft Brush

Blower Wheel

Vent System

Inspect

Every 3

Joints should

Months

be sealed

(1) If furnished with oiling provision.

TABLE 4

GAS SUPPLY SPECIFICATIONS

 

Natural Gas

Natural Gas

 L.P. Gas

Max. Gas Supply Pressure W.C.

12.0

12.0

14.0

(3 kPa)

(3 kPa)

(3.45 kPa)

Nominal Gas Supply Press. W.C

 7.0

7.0

11.0

(1.74 kPa) (1.74 kPa) (2.74 kPa)

Minimal Gas Supply Press. W.C.

5.0

4.5

11.0

(1.25 kPa) (1.12 kPa) (2.74 kPa)

Manifold Press. W.C.

4.0

3.5

10.0

(1 kPa)

(872 kPa) (2.5 kPa)

BTH 120

BTH 150

BTH 120,

& 250

& 199

150 & 199

Summary of Contents for BTH 120-250(A)

Page 1: ...FORE INSTALLING AND USING THIS APPLIANCE INSTALLATION OPERATION SERVICE MAINTENANCE LIMITED WARRANTY WARNING If the information in these instructions is not followed exactly a fire or explosion may result causing property damage personal injury or death Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance WHAT TO DO IF YOU SMELL GAS Do n...

Page 2: ... ProtectionAssociation 1 Batterymarch Park Quincy MA02269 FOREWORD CYCLONE XHE BTH 120 250 ROUGH IN DIMENSIONS TEMPERATURE RISE DEGREES C LITERS PER HOUR Approx Input Liter Model kW Capacity 17 C 22 C 28 C 33 C 39 C 44 C 50 C 56 C 61 C 67 C 72 C 78 C BTH 120 37 Nat 227 1798 1348 1079 898 768 674 598 538 488 450 416 386 BTH 120 35 L P 227 1726 1295 1037 863 738 647 575 519 469 432 397 371 BTH 150 4...

Page 3: ...tion WATER TEMPERATURE CONTROL TABLE OF CONTENTS ROUGH INDIMENSIONS 2 FOREWORD 2 FEATURES 3 4 Water Temperature Control 3 High Limit Switch E C O 4 Dishwashing Machine Requirement 4 Circulating Pump 4 INSTALLATIONINSTRUCTIONS 4 13 Required Ability 4 Insulation Blankets 4 5 Locating The Heater 5 Clearances 5 Hard Water 6 Air Requirements 6 Mechanical Exhausting of Room Air 6 Unconfined Space 6 Conf...

Page 4: ...n Foundation requirements are designed to operate with water flow pressures between 15 and 25 pounds per square inch 103 Kpa and 173 Kpa Flow pressures above 25 pounds per square inch 173 Kpa or below 15 pounds per square inch 103 Kpa will result in improperly sanitized dishes Where pressures are high a water pressure reducing or flow regulating control valve should be used in the 180 F 82 C line ...

Page 5: ...quality water pressure and the environment in which the water heater is installed Water heaters are sometimes installed in locations where leakage may result in property damage even with the use of a drain pan piped to a drain However unanticipated damage can be reduced or prevented by a leak detector or water shut off device used in conjunction with a piped drain pan These devices are available f...

Page 6: ...UNLESS RUBBER ISOLATION PIPE HANGERSARE USED THIS PREVENTSANY VIBRATIONS FROM BEING ALCOVE HARDWATER Where hard water conditions exist water softening or the threshold type of water treatment is recommended This will protect the dishwashers coffee urns water heaters water piping and other equipment See MAINTENANCE section for details of tank cleanout procedure AIR REQUIREMENTS KEEP APPLIANCE AREA ...

Page 7: ...RMINATE EXHAUST OVER PUBLIC AREA WHERE CONDENSATE OR VAPOR CAN CAUSE NUISANCE OR HAZARD ON DIRECT VENT INSTALLATIONS EXHAUST VENT HOOD MUST BE LOCATED 1 30 5cm MINIMUM FROM ANY OPENING IN BUILDING ON DIRECT VENT INSTALLATIONS EXHAUST VENT HOOD MUST BE LOCATED 4 122cm MINIMUM FROM ANY OPENING IN BUILDING ...

Page 8: ... the vent system layout so that proper clearances are maintained from plumbing and wiring Vent pipes serving power vented appliances are classified by building codes as vent connectors Required clearances from combustible materials must be provided in accordance with information in this manual under LOCATION OF HEATER and CLEARANCES and with National Fuel Gas Code and local Codes IMPORTANT Plan th...

Page 9: ... wall Align the holes by drilling a hole through the center of the template from the inside through to the outside The template can now be positioned on the outside wall using the drilled holes as a centering point for the template 3 A MASONRY SIDE WALLS Chisel an opening approximately 1 2 1 3 cm larger than the marked circle B WOODEN SIDE WALLS Drill a pilot hole approximately one quarter inch ou...

Page 10: ...tions should be sealed with a plumbing roof boot or equivalent flashing 3 The intake vent termination and the exhaust vent termination must penetrate the same side of roof 4 The center line of the intake vent termination and the center line of the exhaust vent termination must be no closer than 24 61cm 5 The intake vent terminal and the exhaust vent terminal must be oriented facing downward and th...

Page 11: ...90 elbows with the 4 inch venting is six 6 on the intake and six 6 on the exhaust A 90 elbow is equal to five 5 equivalent feet 1 5m of pipe One 1 90 elbow is equal to two 2 45 elbows Any venting configuration using less than 50 equivalent feet should use 3 inch venting See Table 2 The 3 inch venting terminals provided must be used with the 4 inch venting by adding 4x3 reducing couplings at the ve...

Page 12: ...h is considered normal for low pressure systems Note that fittings such as elbows and tees will add to the pipe pressure drop CAUTION DO NOT USE FLEXIBLE GAS PIPING TABLE 3 MAXIMUM CAPACITY OF PIPE IN CUBIC FEET OF GAS PER HOUR Based upon a Pressure Drop of 0 5 inch Water Column and 0 6 Specific Gravity Gas and max gas pressure of 0 5 psig WARNING THE HEATER IS NOT INTENDED FOR OPERATIONAT HIGHER ...

Page 13: ...ter is too small ask the gas company to install a larger meter having adequate capacity GAS PRESSURE REGULATION Main line gas pressure to the water heater should be between a maximum 14 0 3 45Kpa W C and a minimum as shown in Table 4 that is for Natural Gas 5 0 1 25Kpa W C for BTH 120 250 or 4 5 1 12Kpa W C for BTH 150 199 or for L P Gas 11 0 2 74Kpa W C The inlet gas pressure must not exceed the ...

Page 14: ...TER TANK IS FILLED WITH WATER NOTE This controller is Polarity Sensitive If the Hot and Neutral Supply Voltage is reversed the controller will not sense flame Verify polarity before connecting the unit WATER LINE CONNECTIONS This manual provides detailed installation diagrams see back section of this manual for typical methods of application for the water heaters The water heater may be installed ...

Page 15: ...y return to Step 2 and repeat the entire operating cycle SELF DIAGNOSTIC CONTROLLER A green LED is mounted on the Main Control Board to indicate line voltage polarity is properly connected The green LED is mounted next to connector CN1 Line input connection When 120 VAC input power is properly connected to the Main Control Board the green LED will illuminate If an error is made when connecting 120...

Page 16: ... Clogged gas valve 6 Replace gas valve 7 Faulty gas valve 7 Replace gas valve 8 Defective control 8 Replace control 9 Burner improperly adjusted 9 Adjust burner 10 Dirty burner 10 Clean burner GAS VALVE LED FLASHING This condition results from a failure to establish burner ignition after three successive trials In such cases 1 Investigate the possible cause and remedy any observations 2 Momentaril...

Page 17: ...ntrol problem 2 Water in tank above freezing 2 Temperature probe out of tolerance replace temp probe PossibleCause Remedy 1 Water in tank is low probe 1 Fill tank immersed in steam 2 Probe wiring shorted 2 Repair wiring 3 Defective probe 3 Replace probe PossibleCause Remedy 1 Temp Probe unplugged 1 Check connectors 2 Temp probe wiring damaged 2 Repair wiring 3 Water in tank too hot 3 Normal condit...

Page 18: ...ect orifice PRIOR TO START UP REQUIRED ABILITY INSTALLATION OR SERVICE OFTHIS WATER HEATER REQUIRESABILITY EQUIVALENT TO THAT OF A LICENSED TRADESMAN IN THE FIELD INVOLVED PLUMBING AIR SUPPLY VENTING GAS SUPPLY AND ELECTRICALWORKAREREQUIRED Before attempting start up thoroughly study and familiarize yourself with the exact sequence of operation and all other details on the specific heater being us...

Page 19: ...19 FORYOUR SAFETYREAD BEFORE OPERATING WARNING If you do not follow these instructions exactly a fire or explosion may result causing property damage personal injury or loss of life ...

Page 20: ...LATIONS WARNING BTH HEATERSARE CERTIFIED FOR USE WITHOUT MODIFICATION FOR ALTITUDES UP TO 6500 FEET INSTALLATIONSABOVE 6500 FEET MAY REQUIRE REPLACEMENT OF THE BURNER ORIFICE CALL THE TECHNICAL CENTER 800 527 1953 FOR REQUIREMENTS Some gas utility companies derate their gas for altitude making it unneccessary to install high altitude orifices Call the local gas or utlity company to verify BTU cont...

Page 21: ...alve when finished flushing 4 Turn on the heater electrical disconnect switch DRAINING The heater must be drained if it is to be shut down and exposed to freezing temperatures Maintenance and service procedures may also require draining the heater 1 Turn off the heater electrical disconnect switch 2 Close the cold water inlet valve to heater 3 Open a nearby hot water faucet to vent the system 4 Op...

Page 22: ...and a tank explosion In areas with poor water conditions it may be necessary to inspect the T P valve more often than every three years CAUTION BEFORE MANUALLY OPERATING THE VALVE MAKE SURE THAT A DRAIN LINE HAS BEEN ATTACHED TO THE VALVE TO DIRECT THE DISCHARGE TOAN OPEN DRAIN FAILURE TO TAKE THIS PRECAUTION COULD MEAN CONTACT WITH EXTREMELY HOT WATER PASSING OUT THE VALVE DURING THIS CHECKING OP...

Page 23: ...OT WATER SUPPLIED TO FIXTURES PIPE TO OPEN DRAIN INSTALLINACCORDANCE WITH LOCAL CODES CAUTION IF BUILDING COLD WATER SUPPLY HAS A BACK FLOW PREVENTER CHECK VALVEORWATERMETERWITH CHECK VALVE PROVISIONS FOR THERMALEXPANSION OF WATER IN THE HOT WATER SYSTEM MUST BE PROVIDED NOTE CONNECT RETURN LINE FROM HOT WATER CIRCULATING LOOP IF USED TO COLD WATER INLET LINE PIPE TO OPEN DRAIN INSTALLINACCORDANCE...

Page 24: ...DANGER TEMPERATURE SETTING SHOULD NOT EXCEED SAFE TEMPERATUREATFIXTURES SEEWATERTEMPERATURE CONTROL WARNING ON PAGE 4 IF HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT ADD AN ANTI SCALD VALVE FOR HOT WATER SUPPLIED TO FIXTURES CAUTION IF BUILDING COLD WATER SUPPLY HAS A BACK FLOW PREVENTER CHECK VALVE OR WATER METERWITHCHECKVALVEPROVISIONSFORTHERMAL EXPANSION OF WATER ...

Page 25: ...IT SPECIFICATIONS PAGE28 CAUTION IF BUILDING COLD WATER SUPPLY HAS A BACK FLOW PREVENTER CHECK VALVE OR WATER METER WITH CHECK VALVE PROVISIONS FOR THERMALEXPANSION OF WATER IN THE HOT WATER SYSTEM MUST BE PROVIDED DANGER TEMPERATURE SETTING SHOULD NOT EXCEED SAFE TEMPERATURE ATFIXTURES SEEWATERTEMPERATURECONTROLWARNINGONPAGE 4 IF HIGHER PREHEAT TEMPERATURESARE NECESSARY TO OBTAIN ADEQUATE BOOSTER...

Page 26: ...ECTCIRCULATINGLINEOF180 F 82 C ORBOOSTEDWATER IF USED TO INLETWATER LINETO BOOSTER INSTALLINACCORDANCE WITH LOCALCODES TWO TEMPERATURE TWO HEATERS ONE PRE HEATER ONE BOOSTER HEATER WITH OR WITHOUT BUILDING RECIRCULATION DANGER TEMPERATURE SETTING SHOULD NOT EXCEED SAFE TEMPERATURE ATFIXTURES SEEWATERTEMPERATURECONTROLWARNINGONPAGE 4 IF HIGHER PREHEAT TEMPERATURESARE NECESSARY TO OBTAIN ADEQUATE BO...

Page 27: ...TANK NOTE4 IFTEMPEREDWATERISRECIRCULATED RETURNLINESHOULD BE CONNECTEDATPOINTA DANGER TEMPERATURE SETTING SHOULD NOT EXCEED SAFE TEMPERATURE ATFIXTURES SEEWATERTEMPERATURECONTROLWARNINGONPAGE 5 IF HIGHER PREHEAT TEMPERATURESARE NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT ADD ANANTI SCALD VALVE FOR HOT WATER SUPPLIED TO FIXTURES CAUTION IF BUILDING COLD WATER SUPPLY HAS A BACK FLOW PREVENTER CHECK ...

Page 28: ...ter heating and storage potential of the system cannot be achieved Plus the units with the higher water flow may have a shortened life Unions shown in piping diagrams are not included in the manifold kits Dimensions shown are for minimum space occupied by the water heaters assemblies Space for the venting system and unit servicing must be added ...

Page 29: ...o see if the water heater drain valve is tightly closed Also check the cleanout opening for leakage 2 The apparent leakage may be condensation which forms on cool surfaces of the heater and piping 3 If the outlet of the relief valve is leaking it may represent Excessive water pressure Excessive water temperature Faulty relief valve Excessive water pressure is the most common cause of relief valve ...

Page 30: ...a W C or lower than the minimal gas supply pressure as shown in Table 4 that is for Natural Gas 5 0 1 25 kPa W C for BTH 120 250 or 4 5 1 1 kPa W C for BTH 150 199 or for L P Gas 11 0 2 74 kPa W C pressure Also the manifold pressure should rise during the three 3 second trial for ignition to the manifold pressure value for the individual unit listed in Table 4 that is for Natural Gas 4 0 1 kPa W C...

Page 31: ... to unless an effective method of controlling thermal expansion is also installed at the heater s and operational at all times The relief valve installed on the heater is not an acceptable method 4 SERVICEAND REPAIR EXPENSES Under the limited warranty the warrantor will provide only a replacement water heater or part thereof The owner is responsible for all other costs Such costs may include but a...

Page 32: ...32 A O SMITH WATER PRODUCTS COMPANY 5621 W 115TH STREET ALSIP ILLINOIS 60803 PHONE 1 800 433 2545 FAX 1 800 433 2515 www hotwater com E MAIL parts hotwater com ...

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