A.O. Smith Gdhe 50 Instruction Manual Download Page 1

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Instruction Manual

PRINTED 0413

322286-002

Keep thIs Manual In the pocKet on heater for future reference

whenever MaIntenance adjustMent or servIce Is requIred.

power vent/power dIrect vent Gas Models

wIth hot surface IGnItIon

Model Gdhe 50 serIes 124/125

complies with scaqMd low nox rule 1146.2

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 WATER HEATER LABELING.

resIdentIal Gas water heaters

•

for Your safety

•

AN ODORANT IS ADDED TO THE GAS USED

BY THIS WATER HEATER.

Ashland City, TN 37015

www.hotwater.com

Thank you for buying this energy efficient water heater.

We appreciate your confidence in our products.

Summary of Contents for Gdhe 50

Page 1: ...ow NOx Rule 1146 2 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 WATER HEATER LABELING RESIDENTIAL GAS WATER HEATERS For Your Safety AN ODORANT IS ADDED TO THE GAS USED BY THIS WATER HEATER Ashland City TN 37015 www hotwater com Thank you for buying th...

Page 2: ...r Systems 16 Thermal Expansion 16 Temperature Pressure Relief Valve 17 Gas Piping 18 Supply Gas Regulator 18 Condensate Piping 18 High Altitude Installations 19 Filling the Water Heater 19 Venting 20 Installation Requirements Commonwealth of Massachusetts 22 Termination Clearances Sidewall Power Vent 23 Termination Clearances Sidewall Direct Vent 24 Installation Sequence 25 Direct vent diagram 30 ...

Page 3: ...sinesses to warn of potential exposure to such substances This product contains a chemical known to the State of California to cause cancer birth defects or other reproductive harm This appliance can cause low level exposure to some of the substances listed in the Act This product is certified to comply with a maximum weighted average of 0 25 lead content as required in some areas DANGER WARNING C...

Page 4: ...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 should be no smoking or open flame near the faucet at the time it is open Read and understand this instruction manual and the safety messages herein before installing operating or servicing this water heate...

Page 5: ...5 General safety information ...

Page 6: ...th NFPA 54 Use joint compound or Teflon tape compatible with propane gas Fire and Explosion Hazard Turn off gas lines during installation Contact a qualified installer or service agency for installation and service Excessive gas pressure to gas valve can cause serious injury or death Do not use water heater with any gas other than the gas shown on the rating plate Turn off power to the water heate...

Page 7: ...nings throughout the manual that you must read and be aware of All warnings and all instructions are essential to the proper operation of the water heater and your safety Detailed 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 installed as shown The princi...

Page 8: ... I Junction Box J Gas Control Valve Assembly K Display Board L Top Plastic Enclosure Z Temperature and Pressure Relief Valve AA Rating Plate BB Labels CC Drain Valve DD Vent Terminal EE Metal Drain Pan FF Anode GG Insulation HH Upper Temperature Probe II Access Door REPLACEMENT PARTS AND DELIMING PRODUCTS Replacement parts and recommended delimer may be ordered through authorized servicers or dist...

Page 9: ...0 5 All models Maximum Supply Pressure 14 inches W C 3 48kPa Minimum Supply 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 Recovery Capacities U S Gallons Hr and Liters Hr at Temperature Rise Indicated Input Recovery Capacities Rating Btu hr Rating kW Temp...

Page 10: ... for combustion and ventilation can be obtained See Combustion Air and Ventilation on page 11 9 Locate the water heater where the vent and intake air piping when installed will remain within the maximum equivalent lengths allowed See Venting on page 20 10 Do not locate the water heater where noise such as the Combustion Blower during normal operation will be objectionable in adjacent areas 11 Do n...

Page 11: ...r death Do not apply insulation to the top of the water heater as this will interfere with safe operation of the blower assembly Do not cover the outer door thermostat or temperature pressure relief valve Do not cover the instruction manual Keep it on the side of the water heater or nearby for future reference Do obtain new warning and instruction labels from the manufacturer for placement on the ...

Page 12: ...w do not take in to account the presence of louvers grilles or screens in the openings The required size of openings for combustion ventilation and dilution air shall be based on the net free area of each opening Where the free area through a design of louver or grille or screen is known it shall be used in calculating the size of opening required to provide the free area specified Where the louve...

Page 13: ...installed in the enclosure When ducts are used they shall be of the same cross sectional area as the free area of the openings to which they connect The minimum dimension of rectangular air ducts shall be not less than 3 inches Air From Other Indoor Spaces FIGURE 7 The confined space shall be provided with two permanent openings one commencing within 12 inches 300 mm of the top and one commencing ...

Page 14: ...onic flame sensing requires correct polarity The control system is programmed to monitor the incoming power supply If the Hot and Neutral wires in the 120 VAC power supply are reversed the control system will declare a Fault condition and lock out heating operation will be disabled until the power supply is correctly wired The control system will display the AC Reversed Fault message on the LCD Ch...

Page 15: ... machines meeting the National Sanitation Foundation requirements are designed to operate with water flow pressures between 15 and 25 pounds per square inch 103 kPa and 173 kPa Flow pressures above 25 pounds per square inch 173 kPa or below 15 pounds per square inch 103 kPa will result in improperly sanitized dishes Where pressures are high a water pressure reducing or flow regulating control valv...

Page 16: ...ter heater The water heater is equipped with 3 4 inch NPT water connections NOTE If using copper tubing solder tubing to an adapter before attaching the adapter to the water heater connections Do not solder the water lines directly to the water heater connections It will harm the dip tube and damage the tank T P Valve and Pipe Insulation if supplied 1 Locate the temperature and pressure relief val...

Page 17: ...e of more than four elbows can cause restriction and reduce the discharge capacity of the valve No valve or other obstruction is to be placed between the Temperature Pressure Relief Valve and the tank Do not connect discharge piping directly to the drain unless a 6 15 2 cm air gap is provided To prevent bodily injury hazard to life or property damage the relief valve must be allowed to discharge w...

Page 18: ...rer s specifications If a positive lock up regulator is required follow these instructions 1 Positive lock up gas pressure regulators must be rated at or above the input Btu hr rating of the water heater they supply 2 Positive 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...

Page 19: ...talled in conditioned areas only Drain lines installed in areas that are subject to freezing temperatures should be wrapped with a nationally recognized listed heat tape and or approved insulation for freeze protection Install per manufacturer s instructions Do not common drain with the temperature and pressure relief valve or the condensate line from an air conditioner evaporator coil Slope the c...

Page 20: ...100 30 48 6 15 4 57 95 28 95 The minimum vent length for each pipe size is one 90 plus 2 61 cm of straight pipe and the appropriate termination NOTE The equivalent feet m of pipe listed above are exclusive of the termination That is the termination with an installed screen is assumed to be in the system and the remainder of the system must not exceed the lengths discussed above 3 The exhaust elbow...

Page 21: ...heater to allow drainage of condensation INSTALLATION OF VENT SYSTEM Before beginning installation of piping system thoroughly read the section of this manual VENT PIPE PREPARATION If you are installing your system so that it vents through roof please refer to section titled INSTALLATION OF VERTICAL VENT SYSTEM VENT TERMINAL INSTALLATION SIDEWALL 1 Install the vent terminal by using the cover plat...

Page 22: ... terminal for the horizontally vented gas fueled heating appliance or equipment The sign shall read in print size no less than one half 1 2 inch in size gas vent directly below Keep clear of all obstructions Inspection The state or local gas inspector of the side wall horizontally vented gas fueled equipment shall not approve the installation unless upon inspection the inspector Installation Requi...

Page 23: ... inlet into building or combustion air inlet to any other appliance 4 feet 1 2 m below or to side of opening 1 foot 30 cm above opening D Vertical clearance to ventilated soffit located above the terminal within a horizontal distance of 2 feet 61 cm from the center line of the terminal 12 inches 30 cm K Clearance to a mechanical air supply inlet 3 feet 91 cm above if within 10 feet 3 m horizontall...

Page 24: ...pply 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 9 inches 23 cm for appliances between 10 000 Btu hr 3 kW and 50 000 Btu hr 15 kW 12 inches 30 cm for appliances above 50 000 Btu hr 15 kW D Vertical clearance to ventilated soffit located above the terminal within a horizontal distance of 2 feet 61 cm from the center line ...

Page 25: ...OF ANY VENT PIPE READ THE VENT PIPE MANUFACTURER S INSTALLATION INSTRUCTIONS 1 After the points of termination have been determined use the cover plates as templates to mark the holes for the vent pipes to be inserted through the wall BEWARE OF CONCEALED WIRING AND PIPING INSIDE OF WALL If the vent terminals are being installed on the outside of a finished wall it may be easier to mark both the in...

Page 26: ...no closer than 24 61cm The specifications are displayed in Figures 17 and 18 NOTE Exhaust vent terminal is installed using the same procedure Flat Roof Installation On flat roof installations the intake air and the vent terminations must be a minimum of 24 inches 60 cm above any parapet vertical wall or structure within 10 feet 3 m horizontally See figure 19 Figure 17 Figure 18 INTAKE AIR AND OR V...

Page 27: ...ause intermittent operation INSTALLATION PROCEDURE 1 ROOF TERMINATION see Figure 23 1 Determine best location for termination kit NOTE Roof termination is preferred since it is less susceptible to damage has reduced chances to intake contaminants and less visible vent vapors 2 Cut 1 hole 5 in diameter 3 Partially assemble concentric vent termination kit a Cement Y concentric fitting to larger diam...

Page 28: ...ants shrubs or air conditioning equipment Termination kit positioned so it will not be affected by wind eddy that may allow recirculation of combustion products or airborne leaves or light snow Termination kit positioned where it will not get damaged or be subjected to foreign objects such as stones balls etc Termination kit positioned where the vent vapors will not be objectionable NOTE See the v...

Page 29: ...ion more than 60 in See Figure 20 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 combustion air and vent pipes to concentric vent termination assembly See Figure 25 for proper pipe attachment 8 Operate heater through 1 heat cycle to ensure combustion air and vent pipes are properly c...

Page 30: ... the 24 distance is maintained The wire screen can be removed for space heating at cold climate installation to prevent potential air intake freeze up If wire screen is removed during winter to prevent freezing it is recommended to re install the screen during non space heating seasons If necessary to achieve the 12 minimum clearance above the highest anticipated snow level or grade for the intake...

Page 31: ... inches 15 2cm and above PRIMER It is recommended that Tetrahydrofuran THF be used to prepare the surfaces of pipe and fittings for solvent welding Do not use water rags gasoline or any other substitutes for cleaning PVC or CPVC surfaces A chemical cleaner such as MEK may be used Primer and Cement Tetrahydrofuran THF primer should be used to prepare the surfaces of pipe and fittings for solvent we...

Page 32: ... distance and make a second mark as the primer and cement will most likely destroy your first one Apply primer to the surface of the pipe and fitting socket with a natural bristle brush This process softens and prepares the PVC or CPVC for the solvent cementing step Move quickly and without hesitation to the cementing procedure while the surfaces are still wet with primer E Application of solvent ...

Page 33: ... 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 Section of this manual BLOCKED INTAKE SWITCH SEE FIGURE 33 The Blocked Intake Switch is set up to shut the unit off when a build up of negative pressure in the intake air pipe occurs This switch is a negative pressure switch that req...

Page 34: ...RRORS CAN CAUSE IMPROPER AND DANGEROUS OPERATION VERIFY PROPER OPERATION AFTER SERVICING POWER VENT WIRING SCHEMATIC Figure 34 THIS WATER HEATER IS POLARITY SENSITVE BEFORE APPLYING ELECTRICITY TO THIS HEATER BE CERTAIN THAT SUPPLY NEUTRAL WIRE TO GROUND CHECK INDICATES ZERO VOLTAGE ...

Page 35: ...ced OPERATING INSTRUCTIONS 1 Set the thermostat to the lowest setting 2 Set the ON OFF switch on the control panel to the OFF position 3 Turn off all electrical power to the appliance if service is to be performed BEFORE OPERATING ENTIRE SYSTEM MUST BE FILLED WITH WATER AND AIR PURGED FROM ALL LINES 1 STOP Read the safety information above on this label 2 Set the ON OFF switch on the control panel...

Page 36: ...ter temperature has cooled below this point the power supply 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 temperatures be used to avoid the risk of scalding It is further recommended in all cases that the water temperatures be set for the lowest temp...

Page 37: ...nside 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 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 Th...

Page 38: ...Igniter is being energized The Igniter has been energized and the control system has sensed the required minimum igniter current The check mark icon is visual confirmation of minimum igniter current GAS OFF O N The 24 Volt Gas Valve is being energized The control system has sensed flame at the Main Burner from the Flame Sensor The control system has declared a Fault condition and must be inspected...

Page 39: ... the control system Note Cycling power will not reset the control system if the condition that caused the Fault has not been corrected Control System Menus From the Desktop screen pressing the Operational button directly below Menu on the LCD will display the Main Menu this is where all control system menus are located The table below describes the control system menus Table 11 Menu Description Te...

Page 40: ...st and 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 the Operational Button under SELECT to enter the Temperatures menu If the Temperatures menu is not selected use the Up and Down Buttons to select this menu item Temperatures Heater Status Displa...

Page 41: ...urrent Operating State see Table 10 for a description of the various operational states ECO Contact Blocked Inlet PS Blocked Outlet PS Blower Prover PS displays the current state of the switch contacts open or closed Blower Low On Blower High On displays whether the blower is running at high speed during Pre Post purge and the Heating operational states or the blower is running at low speed during...

Page 42: ...the control system water heater has been energized Burner On Time Total accumulated time the control system has been in the heating operating state burner run time Cycle Count Total accumulated count of heating cycles CCB Version Software version for central control board UIM Version Software version for user interface module Note Historical data is stored in the CCB s memory If this CCB is replac...

Page 43: ...iew details for each Fault or Alert message stored Note fault history memory is cleared after 30 days 1 Blocked Air Intake A7 51 mins ago 2 Blocked Exhaust A8 54 mins ago 3 Low Gas Pressure A6 57 mins ago 4 Blower Prover Failure AC VIEW BACK HELP Fault History Fault Occurrence Description Action Display Select Fault Occurrence from the Main Menu and press the Operational Button under SELECT to ent...

Page 44: ... 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 highlighted in black the Change Contact Name menu item Press the Operational Button under SELECT to open the Change Contact Name menu Show Contact Information Yes Change Contact Name Change Contact Phone Curre...

Page 45: ... odor to develop a A concentration of sulfate in the supply water b Little or no dissolved oxygen in the water c A sulfate reducing bacteria which has accumulated within the water heater this harmless bacteria is nontoxic to humans d An excess of active hydrogen in the tank This is caused by the corrosion protective action of the anode Smelly water may be eliminated or reduced in some water heater...

Page 46: ...void any warranties Aspecial anode rod may be available if water odor or discoloration occurs NOTE This rod may reducebutnoteliminatewater odor problems Thewater supplysystem may require special filtration equipment from a water conditioning company to successfully eliminate all water odor problems Artificially softened water is exceedingly corrosive because the process substitutes sodium ions for...

Page 47: ... of the water heater components described below Burn harzard Hot water discharge Keep hands clear of drain valve discharge To drain the water heater storage tank 1 Turn off the electrical supply to the water heater 2 Turn off the gas supply at the Main Gas Shutoff Valve if the water heater is going to be shut down for an extended period 3 Ensure the cold water inlet valve is open 4 Open a nearby h...

Page 48: ... drain valve may be due to the valve being slightly opened F The drain valve may be leaking at the tank fitting G Leakage from recirculation plug or pipe connection H Leakage from the plug under the cleanout cover I Leakage from the temperature probe connection J Condensate from the exhaust connection Leakage from other appliances water lines or ground seepage should also be checked To check where...

Page 49: ...ergized and will coast to a stop 13 Thecontrolsystemnowentersthestandbymodewhilecontinuing to monitor the internal storage tank water temperature and the state of other system devices If the tank temperature drops below the Operating Set Point minus the Differential setting the control will automatically return to Step 2 and repeat the operating cycle Installation Checklist The list below represen...

Page 50: ...tem Igniter is energized for warm up period 24 V Gas Valve is energized gas flows to Main Burner Is flame sensed at the Main Burner control system monitors the flame sensor Control System Locks Out Displays Fault Msg NO Control System Locks Out Blower Prover Open Fault Msg is displayed NO Control System Locks Out Low Igniter Current Fault Msg is displayed NO Combustion Blower is energized Pre Purg...

Page 51: ...es a Fault condition it will display a Fault message on the control system s LCD with an exclamation mark The control system will lock out and disable heating operation until the condition is corrected The water heater must be serviced by a qualified service agent before operation can be restored Alert Conditions When the control system declares an Alert condition it will display an Alert message ...

Page 52: ...surface igniter is at ignition temperature causing delayed ignition which can cause a fire or explosion mark The water heater will continue to operate during an Alert condition but the water heater must be serviced by a qualified service agent as soon as possible Resetting Control System Lock Outs To reset the control system from a lock out condition turn the power supply off for approximately 20 ...

Page 53: ... 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 system has detected low current AC amps from the Hot Surface Igniter The control system monitors igniter current and will declare this Fault condition if the current is not at or above the programmed min...

Page 54: ...ce tube Combustion Blower is not running when energized Loose or open wiring to Combustion Blower CHANGE BACK ADVANCED Blower Prover Open Fault occurred 2 mins ago The blower prover switch remains open after the blower has been energized Call a service professional Your Company Name Here press DOWN for more The control system has detected the Blocked Intake Air Switch contacts are open Loose or op...

Page 55: ...operation of it in a modified form or any attempt to repair tank leaks or parts will void this warranty SERVICE AND LABOR RESPONSIBILITY UNDER THIS LIMITED WARRANTY THE WARRANTOR WILL PROVIDE ONLY A REPLACEMENT WATER HEATER OR PART THEREOF THEOWNERISRESPONSIBLEFORALLOTHERCOSTS Such costs may include but are not limited to a Labor charges for service removal or reinstallation of the water heater or...

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A.O. Smith Gdhe 50, Instruction Manual

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