A.O. Smith 650A, 740A - Manual

Page 2 - FOREWORD; STANDARD BAROMETRIC DRAFT CONTROL

2 FOREWORD The design of the BTP 540A through 740A models complieswith ANSI Z21.10.3/CSA 4.3 as an automatic circulating tankand an automatic instantaneous type heater. The BTPV 540Athrough 740A models are designed for sidewall venting anddirect venting applications and are certified under UL 795. D...

Page 3 - CHEMICAL VAPOR CORROSION; GENERAL SAFETY INFORMATION; PRECAUTIONS; FIRING WITHOUT WATER.; LIQUID PETROLEUM MODELS; WARNING; TABLE OF CONTENTS; PAGE

3 are different from natural gas models. A natural gas heaterwill not function safely on LP gas and no attempt should bemade to convert a heater from natural gas to LP gas. BTP(V)-540A, 650A & 740A models are not available for usewith Liquefied Petroleum or LP gas. If you have obtained aBTP(V)-5...

Page 4 - IMPROPER COMBUSTION; EXTENDED NON-USE PERIODS; CATHODIC PROTECTION; To reduce the; INSULATION BLANKETS; FEATURES; LOW EMISSION CONTROL

4 and sodium chloride (water softener salt), waxes, and processchemicals are typical compounds which are potentially corrosive.Do not store products of this sort near the heater. Also, air whichis brought in contact with the heater should no contain any ofthese chemicals. If necessary, uncontaminate...

Page 5 - DISHWASHING MACHINE REQUIREMENT; INSTALLATION INSTRUCTIONS; REQUIRED ABILITY

5 Continued manual resetting of high limit control, preceded byhigher than usual water temperature is evidence of high limitswitch operation. The following are possible reasons for highlimit switch operation. • A malfunction in the thermostatic controls would allow thegas valve to remain open causin...

Page 6 - HARD WATER; AIR REQUIREMENTS; VENTING

6 Units, which are to be installed on combustible flooring, mustbe supported by a full layer of hollow concrete blocks, from8 ” ( 2 0 3 . 2 m m ) t o 1 2 ” ( 3 0 4 . 8 m m ) t h i c k a n d e x t e n d i n g12” (304.8 mm) minimum beyond the heater in all directions.The concrete blocks must provide a...

Page 7 - VERTICAL VENTING - FOR BTP MODELS; BAROMETRIC DRAFT CONTROL ASSEMBLY; Do not adjust settings on gate.; VENT CONNECTIONS; A NEGATIVE DRAFT MUST BE MAINTAINED IN VENTING.; FOR BTPV MODELS

7 Heater must be protected from freezing downdrafts duringshutdown periods. The BTP 540A, 650A and 750A water heater are classified as ac a t e g o r y I a p p l i a n c e ( n o n - p o s i t i v e v e n t p r e s s u r e , n o n -condensing) when installed with the supplied barometric draftcontrol ...

Page 8 - Heater; IMPORTANT

8 Refer to Table 2 for limitations of venting system design forhorizontal venting. TABLE 2 BTPV-540A-740A Flue Outlet Dia. (Inches/mm) 9” (228.6) Flue Reducer 9” x 8” Dimensions -Supplied (Inches/mm) 228.6 x 203.2 Minimum Outlet Vent Dia. (Inches/mm) 8” (203.2) Maximum Number 90° 4 Of Elbows 45° 8 M...

Page 9 - DIRECT VENTING - FOR BTPV MODELS; Selkirk Metalbestos Model PS; VENT TERMINAL LOCATIONS-EXHAUST

9 DIRECT VENTING - FOR BTPV MODELS All exhaust vent terminal, flue reducer, and intake vent terminalare supplied with any unit intended for direct venting. Theseparts must be installed without alteration. This heater is category III appliance when used in a direct ventapplication. All national and l...

Page 10 - DIRECT VENT SYSTEM INSTALLATION

10 1. Shall be located not less than 12” (304.8 mm) above grade. 2. Shall be located not less than 3 (.9144 m) feet horizontally from and not less than 3 feet (.9144 m) below an exhaust ventterminal. 3. Shall not be located directly above an exhaust terminal. 4. Shall be located 12” (304.8 mm) above...

Page 11 - GAS PIPING; TABLE 9

11 5. Attach a properly sized length of Selkirk Metalbestos modelPS or model G venting to the exhaust vent adapter using theinner vee bands, see Figures 7 and 7B on page 10. 6. Fill the grooves in both inner vee bands with high-tempsilicone sealant, Dow Corning 736 or equivalent. 7. Position the inn...

Page 12 - TABLE 9A; I N S TA L L I N; ANY SUPPLY PRESSURE TESTING EXCEEDING; GAS; USE SOAP AND WATER SOLUTION OR OTHER; OTHER SOURCES OF IGNITION FOR THIS PURPOSE.; GAS METER SIZE – CITY GASES ONLY

12 TABLE 9A MAXIMUM CAPACITY OF PIPE IN CUBIC FEET OF GAS PER HOUR (Based upon a Pressure Drop of 0.5 inch Water Column and 0.5 Specific Gravity Gas and max. gas press. of .5 psig) LENGTH I N Nominal Iron Pipe Sizes, Millimeters METERS 1/2" 3/4" 1" 1 1/4" 1 1/2" 2" 2 1/2"...

Page 13 - WATER LINE CONNECTIONS; CAUTION; The system installation must conform to these instructions and; RELIEF VALVE

13 ROBERTSHAW ® 7000 DERHC GAS CONTROL VALVE FIGURE 10. WATER LINE CONNECTIONS Following are detailed installation diagrams for typical methodsof application for the water heaters. The water heater may be installed by itself, or with a separatestorage tank, on both single and two-temperature systems...

Page 14 - INSTALLATION DIAGRAMS; ONE TEMPERATURE - ONE HEATER VERTICAL STORAGE TANK; ONE TEMPERATURE - ONE HEATER HORIZONTAL STORAGE TANK; CIRCULATING PUMP WIRING DIAGRAM

14 INSTALLATION DIAGRAMS ONE TEMPERATURE - ONE HEATER VERTICAL STORAGE TANK FORCED CIRCULATION WITH OR WITHOUT BUILDING RECIRCULATION DANGER IF BUILDING COLD WATER SUPPLY HAS ABACKFLOW PREVENTER, CHECK VALVE ORWAT E R M E T E R W I T H C H E C K VA LV E ,PROVISIONS FOR THERMAL EXPANSION OFWATER IN T...

Page 18 - MANIFOLD KITS

18 MANIFOLD KITS Precision cut type “L” all copper A. O. Smith manifold kits assurewater flow balance of all units. Without this balance, the fullwater heating and storage potential of the system cannot beachieved. Plus, the units with the higher water flow may have ashortened life. Unions shown in ...

Page 19 - HEATER WIRING; START UP; PURGING

19 HEATER WIRING IF ANY OF THE ORIGINAL WIRE AS SUPPLIED WITH THEAPPLIANCE MUST BE REPLACED, IT MUST BE REPLACEDWITH 105°C WIRE OR ITS EQUIVALENT, EXCEPT IN THEBURNER HOUSING USE 200°C WIRE. The power burner is wired to the heater as shown in Figure 11for BTP models and Figure 12 for BTPV models. Th...

Page 22 - FOR YOUR SAFETY READ BEFORE LIGHTING; If you do not follow these instructions exactly, a fire or; OPERATING INSTRUCTIONS

22 FOR YOUR SAFETY READ BEFORE LIGHTING 1. Remove thermostat control cover. 2. Set thermostat to lowest setting. 3. Turn burner switch to “OFF”. WARNING: If you do not follow these instructions exactly, a fire or explosion may result causing property damage, personal injuryor loss of life. A. This a...

Page 23 - Temperature

23 SEQUENCE OF OPERATION – Power on.– Heater in standby mode.– Thermostat calls for heat.– Blower motor starts.– Blower operation closes the normally open blower prover/ blocked outlet safety pressure switch. – On proof of airflow, Honeywell S8680J flame control module energized. – 45 seconds prepur...

Page 27 - GENERAL INFORMATION; GAS AND AIR SUPPLY SPECIFICATIONS TABLE 10; Model; MAINTENANCE; MAINTENANCE SCHEDULE

27 GENERAL INFORMATION POWER BURNER The initial start-up procedure of the gas power burner is providedon page 18 thru 21. Refer to Figure 12, burner exploded view forburner components location. The sequence of operation of the power burner is provided onpage 15. For detailed Power Burner Operation, ...

Page 29 - CHECKLIST AND SERVICE; INFORMATION; BURNER OPERATIONAL PROBLEMS

29 ABOVE ALL, DO NOT PLUG THE TEMPERATURE AND PRESSURERELIEF VALVE. THIS IS NOT A SOLUTION AND CAN CREATE AHAZARDOUS SITUATION. CIRCULATING PUMP The water heating system may include a circulating pump. Whereused, it should be lubricated as directed by the circulatormanufacturer. LOW EMISSION POWER B...

Page 30 - TROUBLESHOOTING

30 2. Check the fuses. • The electrical disconnect switch usually contains fuses. 3. The capacity of the heater may have been exceeded by a large demand for hot water. 4. Colder incoming water temperature will lengthen the time required to heat water to the desired temperature. • I f t h e h e a t e...

Page 32 - REPLACEMENT PARTS

32 • Do not proceed to Step 5 unless 24V is detected at “24V”terminal of the Honeywell Module. 5. As soon as the pilot gas valve is energized, check for the burner pilot flame through the burner peek-hole. If the pilotflame is established inside the burner, then proceed toStep 6. • Turn the burner s...

Page 34 - NOTES

A.O. Smith 650A, 740A - Manual

Table of Contents:

Summary

Other A.O. Smith Models