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35

TROUBLESHOOTING CHECKLIST

CHECKLIST

Before calling for service, check the following points to see if the 

cause of trouble can be identified and corrected.
Reviewing this checklist may eliminate the need of a service call 

and quickly restore hot water service. See 

Figure 3

 and 

Figure 

4

 in this manual to identify and locate water heater components.

NOT ENOUGH OR NO HOT WATER

1. 

Be certain the electrical disconnect switch serving the water 

heater is in the ON position.

2. 

Check the fuses.

• 

The electrical disconnect switch usually contains fuses.

•  The heater has fusing.

3. 

If the water was excessively hot, and is now cold, the high limit 

switch may have activated.

• 

See the Temperature Regulation section of this manual 

for more information on how to reset the ECO high limit 

controls.

4. 

The capacity of the heater may have been exceeded by a large 

demand for hot water.

• 

Large demands require a recovery period to restore water 

temperature.

5. 

Cooler  incoming  water  temperature  will  lengthen  the  time 

required to heat water to the desired temperature.

6. 

Look for hot water leakage.

7. 

Sediment or pipe scale may be affecting water heater operation.

ABNORMAL SOUNDS

1. 

Sediment or lime scale accumulations on the elements causes 

sizzling and hissing noises when the heater is operating.

• 

The sounds are normal, however, the tank bottom and 

elements should be cleaned. See the Maintenance section 

of this manual.

2. 

Some of the electrical components of the water heater make 

sounds which are normal.

• 

Contactors will “click” or snap as the heater starts and 

stops.

• 

Transformers and contacts often hum.

WATER LEAKAGE IS SUSPECTED

Refer to Leakage Checkpoint on the following page.

1. 

Check to see if the heater drain valve is tightly closed.

2. 

If the outlet of the relief valve is leaking it may represent:

• 

Excessive water temperature.

• 

Faulty relief valve.

• 

Excessive water pressure.

3. 

Excessive water pressure is the most common cause of relief 

valve leakage. It is often caused by a “closed system”. See 

“Closed  Water  Systems”  and  “Thermal  Expansion”  in  the 

Installation section of this manual for more information.

4. 

Examine the area around the element for gasket leakage.

• 

Tighten the elements or, if necessary, follow the WATER 

AND LIME SCALE REMOVAL procedure to replace the 

gaskets.

IF YOU CANNOT IDENTIFY OR CORRECT THE SOURCE OF 

MALFUNCTION

1. 

Turn the power supply to the water heater off.

2. 

Close the supply water inlet valve to the heater.

3. 

Contact a Qualified Service Agency in your area. 

REPLACEMENT PARTS

Call the toll free phone number listed on the warranty sheet of this 

Instruction Manual for assistance in locating replacement parts. 

When  ordering  parts,  specify  complete  model  no.,  serial  no., 

(see rating plate), quantity and name of part desired. Standard 

hardware items should be purchased locally.

Summary of Contents for 120 series

Page 1: ...CE MAINTENANCE LIMITED WARRANTY Instruction Manual PRINTED 0917 OPTIONAL Thank you for buying this energy efficient water heater We appreciate your confidence in our products PLACE THESE INSTRUCTIONS...

Page 2: ...situation which if not avoided could result in minor or moderate injury CAUTION CAUTION indicates a potentially hazardous situation which if not avoided could result in minor or moderate injury All sa...

Page 3: ...be run with the circuit conductors and connected to the equipment grounding terminal or lead on the water heater HYDROGEN GAS FLAMMABLE Hydrogen gas can be produced in a hot water system served by thi...

Page 4: ...ING DIAGRAMS 41 PIPING DIAGRAMS 47 MANIFOLD KITS 49 NOTES 50 NOTES 51 SAFE INSTALLATION USE AND SERVICE 2 GENERAL SAFETY INFORMATION 3 Precautions 3 Hydrogen Gas Flammable 3 INTRODUCTION 5 Preparing f...

Page 5: ...ts of the heater are identified on pages 7 8 The model and rating plate on page 6 interprets certain markings into useful information Both of these references should be used to identify the heater its...

Page 6: ...51 47 44 18 61 434 246 184 148 123 105 92 82 74 67 61 57 53 24 81 912 328 246 197 164 140 123 109 98 89 82 76 70 27 92 151 369 276 221 184 158 138 123 111 101 92 85 79 30 102 390 410 307 246 205 176...

Page 7: ...by Underwriters Laboratories Inc MODEL AND RATING LISTED 22U1 No OF WATTS PHASE VOLTS AC ELEMENTS EACH RATED MEASURED WATTS COMMERCIAL STORAGE TANK WATER HEATER MODEL NUMBER SERIAL NUMBER ITEM ID PART...

Page 8: ...8 FEATURES AND COMPONENTS Figure 3 Electronic Control Models...

Page 9: ...9 FEATURES AND COMPONENTS Figure 4 Surface Mount Control Models...

Page 10: ...er should be located in an area where leakage of the tank or connections will not result in damage to the area adjacent to the heater or to lower floors of the structure Close to the point of major ho...

Page 11: ...imum water temperature at the hot water tap then you must take special precautions In addition to using the lowest possible temperature setting that satisfies your hot water needs a means such as a MI...

Page 12: ...ly operated at least once a year Caution should be taken to ensure that 1 no one is in front of or around the outlet of the temperature pressure relief valve discharge line and 2 the water manually di...

Page 13: ...r 30 C multiply the ampacities shown above by the appropriate correction factor to determine the maximum allowable load current Ambient Temp F 1 Not more than three conductors in raceway cable or eart...

Page 14: ...volt rating Do not substitute fuses of a different rating Sequence of Operation 1 When the control is powered the UIM should display model information water temperature Operating Set Point heating st...

Page 15: ...15 WIRING DIAGRAMS Figure 8 CCB Central Control Board Control Circuit Diagram Electronic Control Models...

Page 16: ...he heater circuits and includes wiring diagrams All heater circuits are designed for 60 50 hertz alternating current The water heater circuit wiring is 12 AWG AWM or TEW type rated 600 volts 105 C Fus...

Page 17: ...es to terminal L2 with red wires 4 Connect incoming power to terminals L1 and L2 CONVERSION TO THREE PHASE When heater is shipped for connection to a single phase electrical service it may be connecte...

Page 18: ...s the heater circuits and includes wiring diagrams All heater circuits are designed for 60 50 hertz alternating current The water heater circuit wiring is 12 AWG AWM or TEW type rated 600 volts 105 C...

Page 19: ...Disconnect all red wires from terminal L3 4 Connect all red wires to terminal L2 with yellow wires 5 Connect incoming power to terminals L1 and L2 CONVERSION TO THREE PHASE When heater is shipped for...

Page 20: ...odels only 4 Turn on the electrical disconnect switch 5 Observe the operation of the electrical components during the first heating cycle Use care as the electrical circuits are energized 6 Close the...

Page 21: ...ystem THERMOSTAT CONTROLS The water heaters covered in this instruction manual are equipped with adjustable thermostat controls to control water temperature Hot water temperatures required for automat...

Page 22: ...me periods Helps reduce operating costs during unoccupied or peak demand periods Linear Sequencing Banks of heating elements 3 elements per bank are energized according to adjustable 1 to 20 different...

Page 23: ...is a call for heat present and the control system has initiated heating operation Heating elements icon for a water heater equipped with 1 Bank of heating elements Each circle repre sents one heating...

Page 24: ...moni tored water heater functions and components are displayed in this menu Economy Mode Setup Seven day 24 hour time clock with temperature set back capability to reduce operating costs during unoc c...

Page 25: ...ision of temperature control in the storage tank and at points of use This feature can also be used to compensate for building recirculation loops hot water returning to the storage tank that may caus...

Page 26: ...relay coil to either circuit ELEMENT BANK ON Displays the on off status of each Bank of heating elements Yes On No Off ALARM CONDITION Displays the status of the user definable Alarm Output function...

Page 27: ...underneath MENU to enter the Main Menu Notice how the text above the Operational Buttons on the display changes as you navigate through the various menus and screens Use the Up Down buttons to select...

Page 28: ...changes to ACCEPT CANCEL when the adjustment mode is activated and how the current setting is outlined rather than highlighted in black Press the Operational Button underneath ACCEPT to enter and con...

Page 29: ...the Up Down and CHANGE buttons to enter the Mon sub menu Use the Up Down buttons to select highlight in black the Normal Operation Between setting Press the Operational Button underneath SELECT to cha...

Page 30: ...en current tank temperature drops below programmable Alarm SP Fault or Alert Used for external notification whenever a Fault or Alert condition is active Fault Used for notification whenever a Fault c...

Page 31: ...splays non adjustable operational information The control system records and stores the last 9 Fault and Alert messages in chronological order in this menu The most recent will be at the top of the li...

Page 32: ...ry default settings have been restored Press the Operational Button underneath BACK to exit the Restore Factory Defaults menu GENERAL Periodically the drain valve should be opened and the water allowe...

Page 33: ...om water system Check for any leaks and immediately correct any if found 7 Restart the water heater as directed in this manual See the Repair Parts Illustration for anode rod location FLUSHING THE WAT...

Page 34: ...eans Lime scale dissolvents will not remove these types of scale which are occasionally encountered Call the toll free phone number on the back cover of this Instruction Manual to purchase UN LIME and...

Page 35: ...are normal however the tank bottom and elements should be cleaned See the Maintenance section of this manual 2 Some of the electrical components of the water heater make sounds which are normal Conta...

Page 36: ...ll element with new gasket Condensation and dripping may appear on pipes when inlet water temperature is low Pipe fitting may be leaking All water which appears at the heater bottom or on the surround...

Page 37: ...ELECTRIC 1 UNIT LEGEND TEMPERATURE PRESSURE RELIEF VALVE PRESSURE RELIEF VALVE CIRCULATING PUMP TANK TEMPERATURE CONTROL DRAIN FULL PORT BALL VALVE TEMPERATURE GAGE WATER FLOW SWITCH CHECK VALVE WARNI...

Page 38: ...hermostat should be set 5 degrees F higher than the Tank Temperature Control COMMERCIAL ELECTRIC 1 UNIT WITH VERTICAL STORAGE TANK LEGEND TEMPERATURE PRESSURE RELIEF VALVE PRESSURE RELIEF VALVE CIRCUL...

Page 39: ...g thermostat should be set 5 degrees F higher than the Tank Temperature Control COMMERCIAL ELECTRIC 1 UNIT WITH HORIZONTAL STORAGE TANK LEGEND TEMPERATURE PRESSURE RELIEF VALVE PRESSURE RELIEF VALVE C...

Page 40: ...LEGEND TEMPERATURE PRESSURE RELIEF VALVE PRESSURE RELIEF VALVE CIRCULATING PUMP TANK TEMPERATURE CONTROL DRAIN FULL PORT BALL VALVE TEMPERATURE GAGE WATER FLOW SWITCH CHECK VALVE WARNING THIS DRAWING...

Page 41: ...5 degrees F higher than the Tank Temperature Control COMMERCIAL ELECTRIC 2 UNITS WITH VERTICAL STORAGE TANK LEGEND TEMPERATURE PRESSURE RELIEF VALVE PRESSURE RELIEF VALVE CIRCULATING PUMP TANK TEMPERA...

Page 42: ...et 5 degrees F higher than the Tank Temperature Control COMMERCIAL ELECTRIC 2 UNITS WITH HORIZONTAL STORAGE TANK LEGEND TEMPERATURE PRESSURE RELIEF VALVE PRESSURE RELIEF VALVE CIRCULATING PUMP TANK TE...

Page 43: ...SURE RELIEF VALVE PRESSURE RELIEF VALVE CIRCULATING PUMP TANK TEMPERATURE CONTROL DRAIN FULL PORT BALL VALVE TEMPERATURE GAGE WATER FLOW SWITCH CHECK VALVE WARNING THIS DRAWING SHOWS SUGGESTED PIPING...

Page 44: ...the Tank Temperature Control COMMERCIAL ELECTRIC 3 UNITS WITH VERTICAL STORAGE TANK LEGEND TEMPERATURE PRESSURE RELIEF VALVE PRESSURE RELIEF VALVE CIRCULATING PUMP TANK TEMPERATURE CONTROL DRAIN FULL...

Page 45: ...an the Tank Temperature Control COMMERCIAL ELECTRIC 3 UNITS WITH HORIZONTAL STORAGE TANK LEGEND TEMPERATURE PRESSURE RELIEF VALVE PRESSURE RELIEF VALVE CIRCULATING PUMP TANK TEMPERATURE CONTROL DRAIN...

Page 46: ...RE RELIEF VALVE CIRCULATING PUMP TANK TEMPERATURE CONTROL DRAIN FULL PORT BALL VALVE TEMPERATURE GAGE WATER FLOW SWITCH CHECK VALVE WARNING THIS DRAWING SHOWS SUGGESTED PIPING CONFIGURATION AND OTHER...

Page 47: ...ntrol COMMERCIAL ELECTRIC 4 UNITS WITH VERTICAL STORAGE TANK LEGEND TEMPERATURE PRESSURE RELIEF VALVE PRESSURE RELIEF VALVE CIRCULATING PUMP TANK TEMPERATURE CONTROL DRAIN FULL PORT BALL VALVE TEMPERA...

Page 48: ...Control COMMERCIAL ELECTRIC 4 UNITS WITH HORIZONTAL STORAGE TANK LEGEND TEMPERATURE PRESSURE RELIEF VALVE PRESSURE RELIEF VALVE CIRCULATING PUMP TANK TEMPERATURE CONTROL DRAIN FULL PORT BALL VALVE TE...

Page 49: ...ze 1 1 2 Table 15 Manifold Kits with Three Heaters Tank Capacity Gallons Part Number H W D A 52 100109232 66 1 4 91 3 4 27 1 4 13 1 4 80 100109232 70 1 2 95 1 4 31 1 4 9 3 4 120 100109232 73 1 4 99 1...

Page 50: ...50 NOTES...

Page 51: ...51 NOTES...

Page 52: ...52 www hotwater com Copyright 2017 A O Smith Corporation All rights reserved...

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