A.O. Smith BTR 201, Service Handbook

Page 1: ...001 SERVICING SHOULD ONLY BE PERFORMED BY A QUALIFIED SERVICE TECHNICIAN Service Handbook COMMERCIAL GAS WATER HEATERS FOR MODELS BTN 120 thru 400 A Series 100 108 BTR 151 201 Series 100 101 INSTALLATION CONSIDERATIONS PRE SERVICE CHECKS CONSTRUCTION OPERATION SERVICE TROUBLESHOOTING ...

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Page 3: ...151 201 ELECTRICAL SEQUENCE 19 OPERATING SEQUENCE FLOW CHART 20 HEATER CONTROL BOARD DIAGNOSTIC LED INTERPRETATION AND TROUBLESHOOTING 21 IGNITION CONTROL BOARD DIAGNOSTIC LED INTERPRETATION AND TROUBLESHOOTING 22 TEST 2 POLARITY CHECK 23 TEST 3 CONTINUITY CHECK OF HIGH LIMIT ECO 24 TEST 4 UPPER TEMPERATURE PROBE CONTINUITY CHECK 25 TEST 5 CALLING FOR HEAT NO INDUCER OPERATION 26 TEST 6 INDUCER ON...

Page 4: ...fied Agency Any individual firm corporation or company that either in person or through a representative is engaged in and is responsible for 1 the installation testing or replacement of gas piping or 2 the connection installation testing repair or servicing of appliances and equipment that is experienced in such work that is familiar with all precautions required and that has complied with all th...

Page 5: ...is required for testing pressure switches and can replace a gas pressure gauge draft gauge or slack tube manometer for checking gas pressure UEi model EM200 or equivalent Water pressure gauge w lazy hand and hose bibb connection Thermometer 1 1 16 Inch socket with extension for anode replacement Phillips head screwdriver Set of numbered drill bits Standard screwdrivers 3 8 7 16 1 2 and 9 16 inch o...

Page 6: ...to check its operation 3 Check the operation of the limit and operating controls 4 Check the vent system seams and joints and ensure that there is no discharge of flue products into the room 5 Check the input rate Supply gas pressure shall be measured while the water heater is not firing static pressure and while the water heater is firing at full capacity dynamic pressure If the supply gas pressu...

Page 7: ... the installed space The vent system on one or more gas fired appliances can experience down drafts due to the outdoor air pressure being greater than the ambient air pressure in the installed space Where multiple gas fired appliances are installed one or more gas fired appliances can pull air through the vent system s of other appliances installed nearby One common example is in a restaurant inst...

Page 8: ...communicate with the outdoors and must communicate through a vertical or horizontal duct to the outdoors or spaces crawl or attic that freely communicate with the outdoors and must have a minimum free area of a 1 square inch per 3 000 BTU Hr 7cm2 per kW of the total input of all equipment located in the enclosure and b not less than the sum of the areas of all vent connectors in the confined space...

Page 9: ...due to thermal expansion Thermal expansion can cause premature tank failure leakage This type of failure is not covered under the limited warranty Thermal expansion can also cause intermittent Temperature Pressure Relief Valve operation water discharged from the valve due to excessive pressure build up This condition is not covered under the limited warranty The Temperature Pressure Relief Valve i...

Page 10: ...proved reducing thimble is used A service clearance of 24 61 cm should be maintained from serviceable parts such as Temperature pressure relief valves baffles digital thermostats cleanout openings or drain valves The units are approved for installation with side rear and ceiling clearances as indicated below MINIMUM CLEARANCES TO COMBUSTIBLE OR NON COMBUSTIBLE CONSTRUCTION MODELS A RIGHT SIDE B LE...

Page 11: ...ts using natural draft venting The vent must extend at least 3 feet above the highest point where it passes through a roof of a building and at least 2 feet higher than any portion of a building within a horizontal distance of 10 feet for vents of 12 inches in diameter or less References NFPA 54 ANSI Z223 1 may allow reduction to 8 feet with a listed vent cap ...

Page 12: ...ly Gas Inlet and the Supply Gas Pressure Tap The top view of the gas valve shown on the right shows the Main Gas Regulator Manifold Pressure Tap Top Knob and the Limited Bleed Vent Port The main gas regulator is found under the silver cap silver cap for Natural Gas or black cap for Propane screw It is factory preset to 3 5 inches W C and adjusts gas pressure output from 3 0 to 5 inches water colum...

Page 13: ...t The draft inducer does not pressurize the exhaust For larger applications BTN and BTR 151 201 water heaters can be common vented together either in a tapered manifold or constant size manifold Follow the National Fuel Gas Codes requirements for sizing and installation of fan assisted products BTN and BTR 151 201 models may be common vented only with other Category I appliances See the Venting Se...

Page 14: ...t Btu hr Rise Vent Connector Diameter Inches 150 000 154 000 1 Ft 6 6 6 6 6 6 6 6 150 000 154 000 2 Ft 6 6 6 6 6 6 6 6 150 000 154 000 3 Ft 6 6 6 6 6 6 6 6 Number of Heaters Combined Input Btu hr Manifold and Common Vent Diameters Inches 2 300 000 308 000 8 8 7 7 7 6 6 6 3 450 000 462 000 9 9 9 8 8 7 7 7 4 600 000 616 000 12 10 10 9 9 8 8 7 MODEL BTN 180 BTN 199 BTN 199C BTN 200 BTR 201 Input 180 ...

Page 15: ...12 12 10 10 9 9 8 4 1 100 000 14 14 14 12 12 12 10 9 MODEL BTN 310 Input 310 000 Btu hr Total Vent Height Feet Vent Connector Size 6 inches 6 8 10 15 20 30 50 100 Input Btuh hr Rise Vent Connector Diameter Inches 310 000 1 Ft 8 8 8 7 7 6 6 310 000 2 Ft 8 8 8 7 7 7 6 6 310 000 3 Ft 8 8 8 7 7 7 6 6 Number of Heaters Combined Input Btu hr Manifold and Common Vent Diameters Inches 2 620 000 12 10 10 9...

Page 16: ...SURE SWITCH TABLE BTN Models BTR Models Pressure Setting To Close Switch Inches W C 120 2 40 0 07 154 2 20 0 07 180 250 1 60 0 07 199C 3 00 0 10 199 200 1 95 0 07 275 2 30 0 07 310 2 60 0 10 366 2 00 0 07 400 1 75 0 07 151 2 50 0 10 201 2 20 0 07 Note Pressure Switch Contacts are Normally Open N O and close on a fall in pressure ...

Page 17: ...15 Servicing should only be performed by a Qualified Service Technician THERMOSTAT AND IGNITION CONTROL BOARD VIEW ...

Page 18: ...16 Servicing should only be performed by a Qualified Service Technician WHITE RODGERS INTEGRATED CONTROL THERMOSTAT ...

Page 19: ...17 Servicing should only be performed by a Qualified Service Technician WHITE RODGERS IGNITION CONTROL BOARD ...

Page 20: ...18 Servicing should only be performed by a Qualified Service Technician GAS CONTROL VALVE BURNER AREA VIEW ...

Page 21: ...the time the Gas Valve opens the Ignition Control Board waits 3 seconds and then shuts of power to the Silicon Nitride Igniter 11 From the time the Silicon Nitride Igniter s power is shut off the Ignition Control Board waits 3 more seconds to monitor the Flame Sensor 12 If the Flame Sensor does not detect a strong enough flame the Ignition Control Board shuts off the Gas Valve and allows the Exhau...

Page 22: ...20 Servicing should only be performed by a Qualified Service Technician OPERATING SEQUENCE FLOW CHART ...

Page 23: ...esent from on off switch center black wire to ground Check conditions above Check wiring from switch to break box Power is present from center on off terminal Check power from on off switch to ignition board terminal E13 Voltage is not present at E13 to ground Check wiring from on off Left outside terminal to E13 Replace on off switch Power is present at E13 Check power from E14 to water heater co...

Page 24: ...econds at the end of the last cycle 3 Flashes Draft proving pressure switch failed to close within 5 seconds after the inducer was started The low gas pressure switch closes at 5 2 0 4 W C may have remained open Natural Gas only 4 Flashes Open on high temperature limit switch ECO 5 Flashes Not used 6 Flashes 115 volt supply power connection is indicating reversed polarity 7 Flashes Flame sensor re...

Page 25: ...ter switch is On TEST 1 120 VAC check to water heater ON OFF switch Check for 115 125 VAC black wire to ground 115 VAC check to E13 Terminal and 2B receptacle IF THEN Voltage is not present from on off switch center black wire to ground Check conditions above Check wiring from switch to break box Power is present from center on off terminal Check power from on off switch to ignition board terminal...

Page 26: ...3 F If water is below 193 F continuity is correct Continuity is not present meter reads 0 L Replace ECO sensor if water temperature is below 193 F Water is less than 120 F Reset status LED should be on Replace heater control if control will not manually reset CONDITIONS Power On No Hot Water Red heater control Call for Heat LED On Red ignition control board diagnostic LED 4 Flashing Note LED Flash...

Page 27: ...4 Upper Temperature Probe continuity check Red wire to red wire Turn supply power Off for this test IF THEN Test indicates no continuity Replace probe Continuity is indicated Probe should be okay also verify Ohms resistance for water temperature Reading will be approximate CONDITIONS Power On Water below temperature set point Red water heater control Reset Status LED OFF Call for Heat LED Off ...

Page 28: ...et control by interrupting power note possible reasons for this from flashing LED code Replace ignition board Pin 1 to ground has voltage Proceed Pin 3 to ground has no voltage Check wiring harness and plugs Replace inducer CONDITIONS Power On No Hot Water Plugs in Receptacles Red Call for Heat LED ON Inducer Off call for heat LED indicator Diagnostic LED indicator ...

Page 29: ... blower outlet exhaust damper is open Replace blower draft proving switch NATURAL GAS ONLY 24V is present from each switch terminal to ground Check wiring from blower switch to low gas pressure switch Voltage check to each terminal of low gas pressure switch and ground shows only voltage on 1 terminal Switch is open test for a minimum of 5 2 W C Natural Gas or 10 5 Propane flowing supply gas press...

Page 30: ...E4 plug pin 2 to 4 Check wiring and connection from E4 plug to HSI receiving plug Replace HSI Assembly Continuity is present Resistance should be between 11 and 20 Ohms at a temperature of 77 F Voltage is not present between E4 Pin 2 to ground Replace ignition board Voltage is present Continue Voltage is not present between E4 Pin 4 to ground Check wiring and plug connections to HSI Replace HSI Vo...

Page 31: ... warm up no ignition Check for 24V from E1 Pin 12 to ground during 4 second trial Yes Continue No Replace Ignition Board No voltage present E4 Pin 12 to ground Replace ignition board 24 Volt was present from E1 Pin 12 to ground but no main burner Check that air has been purged from gas circuit Check that wiring and connections to gas valve and E1 Pin 9 are correct Check for 24 VAC at E1 Pin 9 to g...

Page 32: ...IN BURNER IF THEN Meter reads 0 or 1 Check meter scale setting to read between 550 and 650 Ohms Replace Gas Valve Meter indicates pilot and main coil have continuity Valve should be okay still no gas to main burner then coil may be stuck Replace Gas Valve CONDITIONS Test 8 completed then Turn off power Disconnect wires from gas valve ...

Page 33: ...ing and plug connections of HSI assembly plug and ignition board receptacles E1 Pin 2 Check that HSI assembly is not cracked or dirty Check that flame prover will be in main flame Replace HSI assembly Still no extended main burner ignition Replace ignition control board CONDITIONS Power On plug connected Main Burner ignites for approximately 5 seconds then goes out Tests 8 and 9 completed Note fla...

Page 34: ...board receptacle E4 Replace lower temperature probe Continuity check red wire pin to red wire pin on upper temperature sensor shows 1 or 0 E3 See Test 4 Check wiring and plug connections to heater control board receptacle Replace upper temperature probe All above checks are okay Check wiring and plug connections to heater control board receptacle Replace upper temperature probe CONDITIONS Main bur...

Page 35: ...ergy Cut Out has opened Check for excessively hot water 203 F or higher Check the resistance of the temperature probes and continuity of the high limit ECO No power Check the breaker Tank is at a set temperature 2 F No action required Tank has cooled below 120 F Preceded by ECO Open indication Push the manual reset button Check the resistance of the temperature probes and continuity of the high li...

Page 36: ...34 Servicing should only be performed by a Qualified Service Technician WIRING DIAGRAM ...

Page 37: ...35 Servicing should only be performed by a Qualified Service Technician NOTES ...

Page 38: ...36 Servicing should only be performed by a Qualified Service Technician NOTES ...

Page 39: ...37 Servicing should only be performed by a Qualified Service Technician NOTES ...

Page 40: ... Central link of www hotwater com for a listing of available Service Handbooks For additional information contact A O Smith Corporation 500 Tennessee Waltz Parkway Ashland City TN 37015 1 800 527 1953 www hotwater com 2013 A O Smith Corporation 317293 001 ...