MODELS BTR(C)120 THRU 500A COMMERCIAL GAS, GLASS-LINED, TANK-TYPE WATER HEATER • INSTALLATION • OPERATION • MAINTENANCE • LIMITED WARRANTY Thank you for buying this energy efficient water heater from A.O. Smith Water Products Company. We appreciate your confidence in our product. CAUTION TEXT PRINTED OR OUTLINED IN RED CONTAINS INFORMATION RELATIVE TO YOUR SAFETY. PLEASE READ THOROUGHLY BEFORE INSTALLING AND USING THIS APPLIANCE. A DIVISION OF A. O.
ROUGH-IN-DIMENSIONS MODELS BTR(C) 120 THROUGH 500 See Models Below FIGURE 1 BTR MODELS 120 THROUGH 500A - TABLE 1A MODEL BTR120 BTR154 BTR180 BTR197 BTR198 BTR199 BTR 200 BTR 250 BTR 251 BTR 275 BTR 305 BTR 365 BTR 400 BTR 500 INPUT APPROX. RATE TANK BTU/Hr. CAP. A 120,000 BTU/Hr. 71 Gal 69.75" 35 Kw/Hr 268 L 177 cm 154,000 BTU/Hr 81 Gal 73.00" 45 Kw/Hr 307 L 185 cm 180,000 BTU/Hr 81Gal 67.50" 53 Kw/Hr 307 L 171 cm 199,000 BTR/Hr 100 Gal 75.00" 58 kW/Hr 379 L 192 cm 199,000 BTU/Hr. 100 Gal 75.
TABLE 1C - HEATER PERFORMANCE DATA BTR MODELS MODEL BTR 120 BTR 154 BTR 180 BTR 197 BTR 198 BTR 199 BTR 200 BTR 250 BTR 251 BTR 275 BTR 305 BTR 365 BTR 400 BTR 500 INPUT APPROX. RATE GAL EFF. BTUH CAP.
TABLE OF CONTENTS Page ROUGH-IN-DIMENSIONS -------------------------------TABLE OF CONTENTS -----------------------------------FOREWORD ------------------------------------------------GENERAL SAFETY INFORMATION ------------------Chemical Vapor Corrosion -------------------------------Improper Combustion -------------------------------------Liquid Petroleum Models ---------------------------------Extended non-use ------------------------------------------Insulation Blankets ----------------------------------
LIQUID PETROLEUM MODELS GENERAL SAFETY INFORMATION Water heaters for propane or liquefied petroleum gas (LPG) are different from natural gas models. A natural gas heater will not function safely on LP gas and no attempt should be made to convert a heater from natural gas to LP gas. PRECAUTIONS LP gas must be used with great caution. It is highly explosive and heavier than air. It collects first in the low areas making its odor difficult to detect at nose level.
• Do not cover the temperature & pressure relief valve. Upon completion of derating of the heater, adjustment to the gas pressure regulator may be required. See CHECKING THE INPUT section in this manual for inlet and manifold pressure requirements. Also due to the input rating reduction required at high altitudes, the output rating of the appliance is also reduced and should be compensated for in the sizing of the equipment for application. • Do not cover the instruction manual.
Troubleshooting-Flue Damper Drive Unit section of this manual. If the water heater does not run with the switch in the "SERVICE" position, then follow the suggestions in the TroubleshootingIgnition Module System and Operational Checklist sections of this manual. 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.
LOCATING THE HEATER CLEARANCES These heaters are approved for installation on combustible flooring in an alcove when the minimum clearance from any combustion construction are followed as indicated in figure 6 and Table 1.
FIGURE 5 WARNING less than one square inch (6.45 square cm) per 4000 Btuh (1.17 Kwh) of the total input of all appliances in the enclosure. If horizontal ducts are used, each opening shall have a free area of not less than one square inch (6.45 square cm) per 2000 Btuh (.58 Kwh) of the total input of all appliances in the enclosure. For Canadian installations consult CAN/CSA B149.1 or .2. FOR SAFE OPERATION PROVIDE ADEQUATE AIR FOR COMBUSTION AND VENTILATION.
• If service is require for the hood portion of the drafthood/ damper drive assembly, they may be separated by unfastening the three screws located in the cast iron base. The following steps shall be followed with each appliance connected to the venting system placed in operation, while any other appliances connected to the venting system are not in operation. The flue damper must be in “OPEN” position when appliance pilot and/or main burners are operating. 1.
TECHNICAL DATA VENTING TYPE B GAS VENT Multiple Gas Fired Tank-Type Heaters When venting mutiple tank type heaters using Type B vent pipe, follow the installation diagram (figure 4) and tables below which give sizing and data based upon NFPA 54/ANSI Z223. 1992. MODEL BTR-120 Input: 120,00Btuh Draft Hood: 5” Number of Heaters 2 3 4 MODEL BTR-154 Input: 154,000 Btuh Draft Hood: 6” Numbers of Heaters 2 3 4 Input Btuh 120,000 120,000 123,000 Combined Input in Thousands of Btuh 240 360 480 Rise 1 Ft. 2 Ft.
TECHNICAL DATA VENTING (Continued) MODEL BTR-250, 251 Input: 250,000, 251,000 Draft Hood: 6” Number of Heaters 2 3 4 MODEL BTR-275 Input: 275,000 Btuh Draft Hood: 6” Numbers of Heaters 2 3 4 MODEL BTR-305 Input: 305,000 Btuh Draft Hood: 8” Number of Heaters 2 3 4 MODEL BTR-365, 400 Input: 365,000, 399,000 Draft Hood: 8” Number of Heaters 2 3 4 Input Btuh 250/251,000 250/251,000 250/251,000 Combined Input in Thousands of Btuh 480 500/502 720 750/753 960/1000/1004 Rise 1 Ft. 3 Ft.
is not a warranty failure. An expansion tank or a similar device may be required in the inlet supply line between the appliance and the meter or valve to compensate for the thermal expansion of the water. MULTIPLE HEATER MANIFOLD Figure 9 and tables on pages 11 and 12 should be used for horizontally manifolding two or more heaters. Also see MULTIPLE-UNIT INSTALLATIONS of MECHANICAL VENTING section for induced draft applications.
Size the main gas line in accordance with Table III. (See last page in manual). The figures shown are for straight lengths of pipe at 0.5 in. W.C. pressure drop, which is considered normal for low pressure systems. Note: Fittings such as elbows, tees and line regulators will add to the pipe pressure drop. Also refer to the latest version of the National Fuel Gas Code. For Canadian installations consult Canadian Installation Code CAN/CGA B149.1 or .2.
GAS METER SIZE — NATURAL GASES ONLY necessary if higher gas pressures are encountered. Gas pressure specified in Table lV, refer to flow pressure taken at pressure tap of automatic gas valve while heater is operating. Be sure the gas meter has sufficient capacity to supply the full rated gas input of the water heater as well as the requirements of all other gas fired equipment supplied by the meter. If gas meter is too small, ask the gas company to install a larger meter having adequate capacity.
INSTALLATION DIAGRAMS-TOP INLET/OUTLET USAGE GENERAL Use of the top inlet water connection requires installation of an inlet dip tube (refer to figure 12). The tube is supplied in the heater. Follow caution labels if applying heat to this fitting. Do not allow pipe dope to contact the plastic tube during installation. The type, size and location of the relief valves must be in accordance with local codes. The locations of the relief valves shown in the installation diagrams are typical.
VERTICAL STORAGE TANK AND FORCED CIRCULATION DANGER TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE TEMPERATURE AT FIXTURES. SEE WATER TEMPERATURE CONTROL WARNING ON PAGE 29. IF HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT WATER SUPPLIED TO FIXTURES.
TWO TEMPERATURE - ONE HEATER HIGH TEMPERATURE STORAGE WITH RECIRCULATION OF SANITIZING LOOP DANGER NOTE 1: TOGGLE SWITCH CONTROLS 180°F (82°C) WATER CIRCULATION. INSTALL ON OR CLOSE TO DISHWASHING MACHINE. TOGGLE SWITCH MUST BE CLOSED (ON) DURING THE RINSE OPERATION AND OPEN (OFF) WHEN DISHWASHER IS NOT OPERATING OR WHEN ON LONG STANDBY. TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE TEMPERATURE AT FIXTURES. SEE WATER TEMPERATURE CONTROL WARNING ON PAGE 30.
INSTALLATION DIAGRAMS-SIDE INLET/OUTLET USAGE A listed temperature and pressure relief valve of adequate capacity is installed on the heater. The locations shown in the installation diagrams on the following pages are typical. The discharge opening of the temperature and pressure relief valve must be piped to an open drain and should not be subject to freezing conditions. DO NOT REDUCE, BLOCK OR PLUG THE DISCHARGE OPENING OF THE VALVE.
ONE OR TWO TEMPERATURE - ONE HEATERS,HIGH TEMPERATURE STORAGE WITH OR WITHOUT RECIRCULATION HEATER WITH OR WITHOUT MIXING VALVE DANGER TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE TEMPERATURE AT FIXTURES. SEE WATER TEMPERATURE CONTROL WARNING ON PAGE 29. IF HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT WATER SUPPLIED TO FIXTURES. HEATER WITH MIXING VALVE AND RECIRCULATED SANITIZING LOOP * PIPE RELIEF VALVE TO OPEN DRAIN.
TWO TEMPERATURE - TWO PRE-HEATERS WITH MIXING VALVE OR BOOSTER HEATER WITH OR WITHOUT BUILING RECIRCULATION TWO PRE-HEATERS WITH MIXING VALVE DANGER TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE TEMPERATURE AT FIXTURES. SEE WATER TEMPERATURE CONTROL WARNING ON PAGE 29. IF HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT WATER SUPPLIED TO FIXTURES.
MEDIUM TEMPERATURE - ONE HEATER WITH AUXILIARY STORAGE TANK FORCED CIRCULATION WITH OR WITHOUT BUILDING RECIRCULATION VERTICAL STORAGE TANK * PIPE RELIEF VALVE TO OPEN DRAIN. **WHEN USING AN A.O. SMITH T-140, -200, -350 OR -400 STORAGE TANK, USE LOWER 3/4” OPENING FOR TANK TEMPERATURE CONTROL. IF BUILDING CIRCULATING LOOP IS USED, CONNECT TO AN OPENING NEAR THE BOTTOM OF THE TANK.
MANIFOLD KITS TWO UNIT MANIFOLD KIT (PART NO. 78692) DIMENSIONS "A" INCHES (CM) MODEL THREE UNIT MANIFOLD KIT (PART NO. 78593) LOW PROFILE VERTICAL HOOD "A" BTR MODELS BTRC MODELS 120 69.75" (177 cm) 69.75" (177 cm) 154 73.00" (185 cm) 73.00" (185 cm) 180 67.50" (171 cm) 70.50" (179 cm) 197 75.00 (192 cm) 81.50" (207 cm) 198 75.00 (192 cm) N/A 199 67.50" (171 cm) 70.50" (179 cm) 200 72.00" (183 cm) 72.00" (183 cm) 250 72.00" (183 cm) 72.00" (183 cm) 251 75.00" (191 cm) 75.
MECHANICAL VENTING The "Sequence of Operation" description will be the same with mechanical venting except, When the appliance thermostat calls for heat: SINGLE UNIT INSTALLATION When mechanical venting of these heaters is desired, the following kits are available. Thermostat contacts "Close" and the power venter blower (120 VAC) is energized. Sufficient draft must be established for the "Draft Prover Switch (N.O.)" to "Close".
All gas and water lines leak tested and open. TABLE Vll PILOT BURNER INFORMATION MODEL All Models* TYPE OF GAS PILOT BURNER PART NUMBER (WITH ORIFICE) RATED ORIFICE SIZE Natural 193314-0 0.018 Propane 193314-1 0.014 Read SEQUENCE OF OPERATION section of this manual prior to lighting and operating this appliance. With above conditions satisfied, light the unit in accordance with the instructions on the Operating label attached to the heater.
ON APPLIANCE “CALL FOR HEAT” the flow of flue gases through the draft hood during normal operation. — Thermostat contacts “close” and relay coil is energized. Relay opens R1 which de-energizes damper motor, allowing damper to open. The open damper switches S1, with R2 and R3 now closed, the electrical circuit energizes the ignition system allowing the gas valve to operate. B.
FOR YOUR SAFETY READ 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. A. B. THIS APPLIANCE IS EQUIPPED WITH AN IGNITION DEVICE WHICH AUTOMATICALLY LIGHTS THE PILOT. DO NOT TRY TO LIGHT THE PILOT BY HAND. BEFORE OPERATING SMELL ALL AROUND THE APPLIANCE AREA FOR GAS . BE SURE TO SMELL NEXT TO THE FLOOR BECAUSE SOME GAS IS HEAVIER THAN AIR AND WILL SETTLE ON THE FLOOR.
FOR YOUR SAFETY READ 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. A. B. THIS APPLIANCE IS EQUIPPED WITH AN IGNITION DEVICE WHICH AUTOMATICALLY LIGHTS THE PILOT. DO NOT TRY TO LIGHT THE PILOT BY HAND. C. BEFORE OPERATING SMELL ALL AROUND THE APPLIANCE AREA FOR GAS . BE SURE TO SMELL NEXT TO THE FLOOR BECAUSE SOME GAS IS HEAVIER THAN AIR AND WILL SETTLE ON THE FLOOR.
SETTING THE WATER HEATER TEMPERATURE AT 120°F WILL REDUCE THE RISK OF SCALDS. Some states or provinces require settings at specific lower temperatures. NOTE: When damper motor is energized, a small delay due to drive mechanism backlash occurs before a visual position change to the damper blade or shaft is noted. DO NOT FORCE, IMPEDE OR OTHERWISE ALTER OR BEND THE DRAFT HOOD ASSEMBLY OR DAMPER DRIVE MECHANISM OR MOTOR.
TYPICAL PILOT AND MAIN BURNER FLAMES MAIN BURNER ASSEMBLY PILOT BURNER ASSEMBLY FIGURE 21 If the preceding burner characteristics are not evident, check for accumulation of lint or other foreign material that restricts or blocks the air openings to the burner or heater. FIGURE 19 • NOTE: Cleaning of main burners. The pilot flame should envelop sensing device with 5/8" (1.6cm) flame, fig. 21. Remove pilot adjustment cover screw, fig. 22.
If the gas valve becomes defective, repairs should not be attempted. A new valve should be installed in place of the defective one. When the heater is operating at full capacity, or full gas input, it should consume 1 cu. ft. of gas in time indicated on Table V. VENTING SYSTEM CHECKING THE INPUT Examine the venting system every six months for obstructions and/or deterioration of the vent piping.
HOT WATER ODOR The time between cleaning will vary from weeks to months depending upon water conditions and usage. On occasion, hot water may develop a strong odor. If this occurs drain the heater completely, flush thoroughly, and refill. If the problem persists, chlorination of the heater and replacement of the factory installed magnesium anodes with aluminum anodes may correct the condition. Refer to A. O. Smith booklet, Form No.
To clean heater through cleanout opening, proceed as follows: • Lower jug to DRAIN POSITION and allow solution to flow out. Observe foaming. 1. Disconnect electrical cover and drain heater. 2. Remove outer cover plate from lower side of heater jacket. 3. Remove six (6) hex head screws securing tank cleanout plate and remove plate. 4. Remove lime, scale, or sediment using care not to damage the glass lining. 5. Inspect cleanout plate gasket: if new gasket is required, replace with A. O. Smith Part No.
TROUBLESHOOTING IGNITION MODULE SYSTEM • If 24 VAC is present, go to Step 2. STEP 2: WITH THE SWITCH IN NORMAL POSITION SET THE THERMOSTAT TO CALL FOR HOT WATER - Check for 24 VAC between the PC board yellow and white wires. Before calling your service agent, the following checklist should be examined to eliminate obvious problems from those requiring replacement or servicing. • If 24 VAC is present, go to Step 3. • If 24 VAC is not present then check between yellow wire and thermostat.
OPERATIONAL CHECKLIST This checklist in conjunction with “TROUBLESHOOTING” and the “SEQUENCE OF OPERATION” should be used as an on-the-job troubleshooting guide to identify the cause of incorrect system operation and suggest a remedy for its correction. Because improper piping and wiring can result in unsatisfactory system performance, it is suggested that the installation by examined before using the checklist.
Model BTR(C) Limited Warranty A. O. Smith Corporation, the warrantor, extends the following LIMITED WARRANTY to the owner of this water heater. 1. THE TANK If the glass-lined tank in this water heater shall prove upon examination by the warrantor to have leaked due to natural corrosion from potable water therein, during the first THREE years after initial installation, the warrantor will supply a complete new A. O. Smith water heater of equivalent size and current model.
