A.O. Smith 100 Series Instruction Manual

COMMERCIAL GAS HIGH EFFICIENCY WATER HEATERSService HandbookPRINTED IN THE U.S.A. 0914 329298-000500 Tennessee Waltz ParkwayAshland City, TN 37015FOR

9Servicing should only be performed by a Qualied Service Technician5. When installing multiple water heaters in the same gas supply system it is rec

10Servicing should only be performed by a Qualied Service Technician7. Record the supply gas pressure.8. Use the Enable/Disable Switch located on t

11Servicing should only be performed by a Qualied Service Technician2. BLOWER OPERATION ERROR CHANGE BACK ADVANCEDBlower Operation ErrorFault occurr

12Servicing should only be performed by a Qualied Service TechnicianPRESSURE SWITCH TESTSComplete pressure switch testing involves three procedures:•

13Servicing should only be performed by a Qualied Service TechnicianCONTINUITY TEST DURING OPERATIONThis test is performed while the Combustion Blowe

14Servicing should only be performed by a Qualied Service Technician• Blower Prover Switch - normally open contacts, close on a rise in pressure.•

15Servicing should only be performed by a Qualied Service TechnicianBlocked Air Intake: Note these are negative pressures; in a vacuum. If the pressu

16Servicing should only be performed by a Qualied Service Technician3. BLOWER PROVER OPEN CHANGE BACK ADVANCEDBlower Prover OpenFault occurred 2 min

17Servicing should only be performed by a Qualied Service Technician4. IGNITION FAILURECHECK/ REPAIR• Determine whether or not the burner is ignitin

18Servicing should only be performed by a Qualied Service Technician• Reinsert connector on Flame Sensor and make sure the electrical connection is

1TABLE OF CONTENTSINTRODUCTION ...2Qualications ...

19Servicing should only be performed by a Qualied Service Technician• Remove and reinsert the circuit board end of the Gas Control Valve connector.

20Servicing should only be performed by a Qualied Service Technician5. BLOCKED AIR INTAKE CHANGE BACK ADVANCEDBlocked Air IntakeFault occurred 2 min

21Servicing should only be performed by a Qualied Service Technician6. BLOCKED EXHAUST CHANGE BACK ADVANCEDBlocked ExhaustFault occurred 2 mins agoR

22Servicing should only be performed by a Qualied Service Technician7. FLAME SENSOR ERROR CHANGE BACK ADVANCEDFlame Sensor (error)Fault occurred 1 m

23Servicing should only be performed by a Qualied Service TechnicianGAS CONTROL VALVE VOLTAGE TESTS1. The animated Gas Control Valve Status Ic

24Servicing should only be performed by a Qualied Service TechnicianFLAME SENSORIgnition of the Burner is controlled electronically. The principle of

25Servicing should only be performed by a Qualied Service TechnicianFLAME SENSING CURRENT TESTDuring the heating cycle the ame sensing current is no

26Servicing should only be performed by a Qualied Service Technician8. NO WATER CHANGE BACK ADVANCEDNo WaterAlert:Alert occurred 2 mins agoNo water

27Servicing should only be performed by a Qualied Service TechnicianCLEANING METHOD:If corrosion is present on the air side of the anode, use a wire

28Servicing should only be performed by a Qualied Service Technician9. ANODE SHORTED CHANGE BACK ADVANCEDAnode ShortedAlert:Alert occurred 0 mins ag

2Servicing should only be performed by a Qualied Service TechnicianINTRODUCTIONThis Service Handbook covers the water heater Model and Series numbers

29Servicing should only be performed by a Qualied Service Technician10. TEMPERATURE PROBE SHORT (UPPER OR LOWER) CHANGE BACK ADVANCEDUpper Temp Prob

30Servicing should only be performed by a Qualied Service TechnicianIf the resistance of the Temperature Sensor is below 390 ohms the Control System

31Servicing should only be performed by a Qualied Service TechnicianResults/Actions• If the ohm meter shows continuity (closed circuit) between the

32Servicing should only be performed by a Qualied Service Technician11. TEMPERATURE PROBE OPEN (UPPER OR LOWER) CHANGE BACK ADVANCEDLower Temp Probe

33Servicing should only be performed by a Qualied Service TechnicianVENTINGThis section of the Service Handbook is not a complete venting installatio

34Servicing should only be performed by a Qualied Service TechnicianINTAKE AIR CONNECTIONThe intake air connection has a screen and a hose barb insta

35Servicing should only be performed by a Qualied Service TechnicianELECTRICAL CONNECTIONS – ALL MODELSThe water heaters covered in this Service Hand

36Servicing should only be performed by a Qualied Service Technician5. Connect the ground wire from the power supply to the grounding lug inside the

37Servicing should only be performed by a Qualied Service TechnicianINSTALLATION CHECK LISTThe list below represents some of the most critical instal

38Servicing should only be performed by a Qualied Service TechnicianOPERATION AND SERVICEHOW IT WORKSThis section of the Service Handbook will cover

3Servicing should only be performed by a Qualied Service TechnicianINSTALLATION CONSIDERATIONSThis section of the Service Handbook covers some

39Servicing should only be performed by a Qualied Service TechnicianService Note: The 5 pin PWM signal plug MUST remain plugged in to the 5 pin socke

40Servicing should only be performed by a Qualied Service TechnicianBLOWER SPEED CONTROL – SUF 119300 THRU 119500The CCB monitors a feedback signal f

41Servicing should only be performed by a Qualied Service TechnicianVARIABLE FREQUENCY DRIVE – SUF 119300 THRU 119500The SUF 119300 - 119500 models h

42Servicing should only be performed by a Qualied Service TechnicianBURNER ASSEMBLYThe Burner is a radial design burner with a steel ber jacket on t

43Servicing should only be performed by a Qualied Service TechnicianCOMBUSTION BLOWER AND BURNER REMOVAL/ INSTALLATION INSTRUCTIONSRefer to the Combu

44Servicing should only be performed by a Qualied Service TechnicianSPARK IGNITERThe water heaters covered in this Service Handbook use a Spark Ignit

45Servicing should only be performed by a Qualied Service TechnicianThe Control System is programmed to start sparking a few seconds before the Gas C

46Servicing should only be performed by a Qualied Service TechnicianGAS ORIFICE - SUF 119300 THRU 119500 MODELSRefer to Orifice Chart below for corre

47Servicing should only be performed by a Qualied Service TechnicianCCB (CENTRAL CONTROL BOARD)The CCB is a printed circuit board mounted inside a pr

48Servicing should only be performed by a Qualied Service TechnicianCCB COVER REMOVAL AND REPLACEMENTThe cover on the CCB enclosure must be removed f

4Servicing should only be performed by a Qualied Service TechnicianFEATURES AND COMPONENTSCOMBUSTION BLOWER & BURNER ASSEMBLYAir Intake AssemblyL

49Servicing should only be performed by a Qualied Service TechnicianCCB CIRCUIT BOARD LAYOUT11121J16J5J3J13J4J17J10J9J14J15J1J6J121111111111112222222

50Servicing should only be performed by a Qualied Service TechnicianCCB CONNECTION IDENTIFICATIONJ1 Socket - High Voltage InPIN # DESCRIPTION1 Ground

51Servicing should only be performed by a Qualied Service TechnicianJ14 Socket - Limit StringPIN # DESCRIPTION1 Anode2 Grounding3 Flame Sensor4 Conde

52Servicing should only be performed by a Qualied Service TechnicianWIRING DIAGRAM – SUF 60120 THRU 100250

53Servicing should only be performed by a Qualied Service TechnicianWIRING DIAGRAM – SUF 119300 THRU 119500

54Servicing should only be performed by a Qualied Service TechnicianCONTROL OVERVIEWInteraction with the water heater controller is through an UIM di

COMMERCIAL GAS HIGH EFFICIENCY WATER HEATERSVisit the "Information Central" link of www.statewaterheaters.com for a listing of available Ser

5Servicing should only be performed by a Qualied Service TechnicianTOP VIEW: SUF 60120 - 100250 MODELSBlocked Exhaust SwitchPowered Anode (Short, SUF

6Servicing should only be performed by a Qualied Service TechnicianSEQUENCE OF OPERATION FLOW CHARTYES NOWater is heated to set point24 Volt Gas Valv

7Servicing should only be performed by a Qualied Service TechnicianFAULT AND WARNING CODES1. LOW GAS PRESSURE CHANGE BACK ADVANCEDLow Gas PressureFa

8Servicing should only be performed by a Qualied Service TechnicianGAS SUPPLY SYSTEMSLow pressure building gas supply systems are defined as those sy