background image

39

THE DESKTOP SCREEN

During normal operation the control system will display the Desktop 

screen on the LCD which is the default screen. The control system 

will return to the Desktop screen when there are no active Fault or 

Alert conditions or when there has been no user input for several 

minutes.

•  Manufacturer  and  water  heater  model  information  is  displayed 

in  Title  Bar  at  the  top  of  the  Desktop  screen.  Menu  titles  are 

displayed  in  the  Title  Bar  when  navigating  the  control  system 

menus.

•  The  first  temperature  shown  on  the  Desktop  screen,  Tank 

Temperature,  is  the  temperature  of  the  water  inside  the  water 

heater's storage tank - commercial models only.

•  The Operating Set Point is also shown on the Desktop screen. 

The Operating Set Point is the temperature at which the control 

system will maintain the water inside the storage tank.

•  Beneath the Operating Set Point is the Status line. The Status 

line shows the current operational state of the control system in 

real time. See “Table 13 – Operating States” for a description of 

the various operating states.

•  The  Desktop  screen  also  displays  animated  Status  Icons  to 

convey operational information, see “Table 12 – Status Icons” for 

a complete list and description of the Status Icons.

OVERVIEW

The  water  heaters  covered  in  this  manual  are  equipped  with  an 

electronic  control  system  that  regulates  water  temperature  inside 

the storage tank. Heating cycles and ignition are managed by the 

control system. The ECO (energy cut out), Flame Sensor, pressure 

switches and Temperature Probe is monitored by the control system. 

The Combustion Blower, Igniter and the 24 Volt Gas Control Valve 

are all energized by the control system.

The main components of the control system are a UIM (user interface 

module) and a CCB (central control board). The UIM is located on 

the top front side of the water heater. The CCB is mounted on top of 

the water heater inside a protective enclosure.

CONTROL SYSTEM NAVIGATION

All operational information and user settings are displayed and 

accessed from the UIM. The UIM houses the control system's LCD 

(liquid crystal display) and five snap acting (momentary) user input 

buttons;  an  up,  down  and  three  multifunction  operational  buttons 

below the LCD, see Figure 36.

USER INPUT BUTTONS

•  The up and down buttons are used to navigate menus and adjust 

user settings.

 

•  The  operational  buttons  are  used  to  enter/exit  menus,  select 

menu items, activate adjustment modes and confirm or cancel 

new  user  settings. The  operational  buttons  are  multifunctional, 

their current function is defined by the text that appears directly 

above each button on the LCD screen. 

Tank Temperature 

  103°F

Operating Set Point 

  120°F

Status: Heating

MENU

HELP

GAS

OFF

O

N

MANUFACTURER / MODEL INFORMATION

LCD Screen

Information

Display

Status Icons

3 Operational buttons:

enter/exit menus,

select menu items,

activate adjustment modes,

confirm/cancel changes.

Up & Down buttons:

navigate menus,

adjust user settings

Title Bar

Operational buttons are multifunctional. Their current function is defined by

the text that appears directly above each button on the LCD screen.

UIM (user interface module)

Desktop Screen Shown

UP

DN

Figure: 36

CONTROL SYSTEM OPERATION

Summary of Contents for BTXL-100

Page 1: ...131 ALL TECHNICAL AND WARRANTY QUESTIONS SHOULD BE DIRECTED TO THE LOCAL DEALER FROM WHOM THE WATER HEATER WAS PURCHASED IF YOU ARE UNSUCCESSFUL CALL THE TECHNICAL SUPPORT PHONE NUMBER SHOWN ON THE WA...

Page 2: ...Piping 23 High Altitude Installations 23 Filling The Water Heater 23 INSTALLATION REQUIREMENTS FOR THE COMMONWEALTH OF MASSACHUSETTS 24 VENTING INSTALLATION 25 Vent Installation Considerations 25 U S...

Page 3: ...irth defects or other reproductive harm and requires businesses to warn of potential exposure to such substances This product contains a chemical known to the State of California to cause cancer birth...

Page 4: ...sing any electrical appliance connected to the hot water system If hydrogen is present there will probably be an unusual sound such as air escaping through the pipe as the water begins to flow THERE S...

Page 5: ...5 GENERAL SAFETY INFORMATION...

Page 6: ...ad and understand instruction manual Breathing Hazard Carbon Monoxide Gas Property Damage Hazard All water heaters eventually leak Do not install without adequate drainage CAUTION Fire and Explosion H...

Page 7: ...installation diagrams are also found in this manual These diagrams will serve to provide the installer with a reference It is essential that all venting water piping gas piping and wiring be installe...

Page 8: ...T Table 1 ROUGH IN DIMENSIONS Units A B C D E F G H I 50G Inches 66 75 49 25 22 00 15 75 3 00 8 00 8 00 62 00 65 00 cm 169 5 125 09 55 88 40 00 7 62 20 32 20 32 157 48 165 1 75G Inches 64 71 45 64 27...

Page 9: ...ply Pressure for Natural Gas 3 50 87kPa Minimum Supply Pressure for Propane Gas 8 00 1 99kPa Minimum pressure must be maintained under both load and no load dynamic and static conditions Table 3 RECOV...

Page 10: ...CODES 50 GALLON UNIT FEATURES AND COMPONENTS 24 18 35 31 9 4 2 3 19 29 20 22 23 21 1 12 16 25 11 17 33 13 26 27 34 SEE ACCESS PANEL CAUTION 28 30 32 21 18 5 14 15 Caution Thisaccesspanelcovers a 2 NPT...

Page 11: ...stallation of Vent System and Condensate Piping for more information VACUUM RELIEF VALVE INSTALL PER LOCAL CODES 75 GALLON UNIT FEATURES AND COMPONENTS CONT 24 18 35 31 9 4 2 3 19 22 23 21 1 12 17 25...

Page 12: ...Board 12 Top Plastic Enclosure 13 Display Enclosure 14 Exhaust Elbow Assembly 15 Condensate Tubing 16 Off On Switch 17 Display Label 18 Hot Water Outlet 19 Gas Supply 20 Main Manual Gas Shutoff Valve...

Page 13: ...d to flow freely from the exhaust elbow and for obstructions in the exhaust venting and exhaust vent terminal Also verify that the vent length does not exceed the maximum allowed as shown in the Vent...

Page 14: ...er where an adequate supply of fresh air for combustion and ventilation can be obtained See Combustion Air and Ventilation on Page 15 9 Locate the water heater where the vent and intake air piping whe...

Page 15: ...proper combustion potentially resulting in fire asphyxiation serious personal injury or death Do not apply insulation to the top of the water heater as this will interfere with safe operation of the b...

Page 16: ...ngs to provide fresh air must be provided that accommodate the requirements for all appliances in the room and the exhaust fan Undersized openings will cause air to be drawn into the room through the...

Page 17: ...the bottom of the enclosure The horizontal ducts shall communicate directly with the outdoors See Figure 7 Each duct opening shall have a minimum free area of 1 square inch per 2 000 Btu hr 1100 mm2...

Page 18: ...manufacturer s instructions for installation of the valves Before changing the factory setting on the thermostat read theTemperature Regulation section in this manual This water heater shall not be co...

Page 19: ...pain threshold 116 46 7 35 minutes 45 minutes 122 50 1 minute 5 minutes 131 55 5 seconds 25 seconds 140 60 2 seconds 5 seconds 149 65 1 second 2 seconds 154 67 8 instantaneous 1 second U S Government...

Page 20: ...lock up gas pressure regulator s should be installed no closer than 3 feet 1 meter and no farther than 8 feet 2 4 meters from the water heater s inlet gas connection 3 After installing the positive lo...

Page 21: ...h as pressure reducing valves check valves and back flow preventers Devices such as these cause the water system to be a closed system THERMAL EXPANSION As water is heated it expands thermal expansion...

Page 22: ...quipment of materials as meeting the requirements for Relief Valves for Hot Water Supply Systems ANSI Z21 22 CSA 4 4 and the code requirements of ASME If replaced the new T P valve must meet the requi...

Page 23: ...copper tubing iron or steel pipe for the condensate drain line Condensate drain lines should be installed in conditioned areas only Drain lines installed in areas that are subject to freezing temperat...

Page 24: ...he horizontally vented gas fueled heating appliance or equipment The sign should read in print size no less than one half 1 2 inch in size GAS VENT DIRECTLY BELOW KEEP CLEAR OF ALL OBSTRUCTIONS INSPEC...

Page 25: ...proper cement must be used for all joints including joining the pipe to Termination PVC Material If Polypropylene pipe and fittings are used the metal joint connector rings available from the Polyprop...

Page 26: ...lations Table 5 M G Duravent PolyPro Nominal Pipe Diameter Flue Outlet Adapter Adapter Connector Ring Connector 90 Degree Elbow Vent Material Terminal s 2 2PPS AD PPS PAC 2PPS LB 2PPS E90 2PPS 2PPS 2P...

Page 27: ...ON The first step is to determine where the vent pipe will terminate See Figures 13 Figure 14A and Figure 15 The vent may terminate through a sidewall as shown in Figure 13 and Figure 15 or through th...

Page 28: ...ow be positioned on the outside wall using the drilled holes as a centering point for the template A MASONRY SIDE WALLS Chisel an opening approximately 1 2 1 3 cm larger than the marked circle B WOODE...

Page 29: ...ir supply inlet into building or combustion air inlet to any other appliance 6 inches 15 cm for appliances up to 10 000 Btu hr 3 kW 12 inches 30 cm for appliances between 10 000 Btu hr 3 kW and 100 00...

Page 30: ...l air supply inlet into building or combustion air inlet to any other appliance 6 inches 15 cm for appliances up to 10 000 Btu hr 3 kW 12 inches 30 cm for appliances between 10 000 Btu hr 3 kW and 100...

Page 31: ...ing 3 The air intake termination and the exhaust vent termination must penetrate the same side of roof 4 The center line of the air intake termination and the center line of the exhaust vent terminati...

Page 32: ...E HIGHEST ANTICIPATED SNOW LEVEL 12 MINIMUM CLEARANCE ABOVE HIGHEST ANTICIPATED SNOW LEVEL 24 MINIMUM SEPARATION EXHAUST MUST BE AT SAME LEVEL OR ABOVE INTAKE TERMINAL Figure 21 Figure 23 Figure 24 Fi...

Page 33: ...ration INSTALLATION VERTICAL ROOF TERMINATION 1 Determine best location for termination kit NOTE Roof termination is preferred since it is less susceptible to damage has reduced chances to intake cont...

Page 34: ...ioned where the vent vapors will not damage plants shrubs or air conditioning equipment Termination kit positioned so it will not be affected by wind eddy that may allow recirculation of combustion pr...

Page 35: ...re than 60 1 5 m See Figure 25 Do not use field supplied couplings to extend pipes Airflow restriction will occur and the heater pressure switch may cause intermittent operation 7 Cement heater combus...

Page 36: ...or hole using the base as a template 4 Screw the Cap to the Base using the supplied screws 5 Once the vent termination and pipes are secured the wall penetrations will need to be sealed from the inter...

Page 37: ...37 LIGHTING AND OPERATION LABELS...

Page 38: ...ply to the water heater must be turned off and on again to reset the control system Contact your dealer or servicer if continued high limit switch operation occurs It is recommended that lower water t...

Page 39: ...ressure switches and Temperature Probe is monitored by the control system The Combustion Blower Igniter and the 24 Volt Gas Control Valve are all energized by the control system The main components of...

Page 40: ...tion Blower is being energized The Blower Prover pressure switch contacts have closed The check mark icon is visual confirmation of contact closure The Igniter is being energized GAS OFF O N The 24 Vo...

Page 41: ...on that caused the Fault has not been corrected Heating Disabled The heating is disabled by the Enable Disable On Off switch in front of the unit CONTROL SYSTEM MENUS From the Desktop screen pressing...

Page 42: ...description of control system menus Use the Up and Down Buttons to view all control system menus from the Main Menu With Temperatures menu selected highlighted in black in the Main Menu screen press...

Page 43: ...he hot water supply temperature varies greatly from the Operating Set Point setting These settings are adjusted in the same way described for the Operating Set Point and Differential Adjustment Operat...

Page 44: ...mulated time the control system has been in the heating operating state burner run time Total Cycle Count Total accumulated count of heating cycles Config CRC A number associated with the configuratio...

Page 45: ...event will replace the oldest Press the Operational Button under VIEW to view details for each Fault or Alert message stored NOTE fault history memory is cleared after 30 days 1 Blocked Air Intake A7...

Page 46: ...m Show Contact Information Yes Change Contact Name Change Contact Phone Current Contact Info 000 000 0000 Access Code UPDATE CANCEL Service Contact Information Using the UP and DOWN buttons select hig...

Page 47: ...itions will cause a reaction between this rod and the water The most common complaint associated with the anode rod is one of a rotten egg smell in the hot water The smell is a result of four factors...

Page 48: ...ciated with the anode rod is a rotten egg smell produced from the presence of hydrogen sulfide gas dissolved in the water IMPORTANT Do not remove this rod permanently as it will void any warranties A...

Page 49: ...ning And Flushing on Page 49 Replace the Temperature Pressure Relief Valve with a properly rated sized new one see Temperature Pressure Relief Valve on Page 22 for instructions on replacement DISCHARG...

Page 50: ...and terminate it to an adequate drain 5 Ensure the drain hose is secured before and during the entire flushing procedure Flushing is performed with system water pressure applied to the water heater 6...

Page 51: ...tting G Leakage from recirculation plug or pipe connection H Leakage from the plug under the cleanout cover I Leakage from the temperature probe connection Not shown in figure J Condensate from the ex...

Page 52: ...cycle to purge the water heater of all combustion gases When the post purge cycle is complete the blower is de energized and will coast to a stop 12 The control system now enters the standby mode whi...

Page 53: ...le is activated Blower Prover switch contacts confirmed closed by control system Igniter is energized 24 V Gas Valve is energized gas flows to Main Burner Is flame sensed at the Main Burner control sy...

Page 54: ...e water heater Refer to the parts list for more information or call the parts department or technical support phone number listed on the back cover of this manual for further assistance OPERATIONAL PR...

Page 55: ...ONDITIONS When the control system declares an Alert condition it will display an Alert message on the control system s LCD with a question mark The water heater will continue to operate during an Aler...

Page 56: ...CHANGE BACK ADVANCED Ignition Failure Fault occurred 2 mins ago The water heater has failed to ignite the burner Call a service professional Your Company Name Here press DOWN for more The control syst...

Page 57: ...Blocked Intake Air Switch contacts are open Loose or open wiring to the Blocked Intake Air Switch Excessive equivalent pipe length exceeded the maximum number of 90 elbows or wrong pipe size used in...

Page 58: ...ABEL ALL WIRES PRIOR TO DISCONNECTION WHEN SERVICING CONTROLS WIRING ERRORS CAN CAUSE IMPROPER AND DANGEROUS OPERATION VERIFY PROPER OPERATION AFTER SERVICING Figure 41 POWER VENT WIRING SCHEMATIC WIR...

Page 59: ...is also installed at the heater s and operational at all times The temperature and pressure relief valve installed on the heater is not an acceptable method 4 SERVICE AND REPAIR EXPENSES Under the li...

Page 60: ...60 www hotwater com 500 Tennessee Waltz Parkway Ashland City TN 37015 Tech Support 800 527 1953 Parts 800 433 2545 Copyright 2013 A O Smith Corporation All rights reserved...

Reviews: