American Water Heater 74 Gallon 80 Thermal Efficiency UltraLow NOx Heavy Duty Commercial Gas Water Heater User Manual

							11SETTING THE WATER HEATER TEMPERATURE AT 120°F (49°C) 
(APPROX. "
" MARK ON FACE OF THE TEMPERATURE ADJUSTING 
DIAL) WILL REDUCE THE RISK OF SCALDS.  Some States or Provinces 
require settings at specific lower temperatures.
Figure 6 shows the approximate water temperatures produced at various 
thermostat settings. Short repeated heating cycles caused by small hot 
water uses can cause temperatures at the point of use to exceed the 
thermostat setting by up to 20°F (11°C). If you experience this type of 
use you should consider using lower temperature settings to reduce 
scald hazards.
Valves for reducing point of use temperature by mixing cold and hot 
water are available.  Also available are inexpensive devices that attach 
to faucets to limit hot water temperatures. Contact a licensed plumber 
or the local plumbing authority.
To avoid any unintentional changes in water temperature settings, the 
control has a tamper resistant feature for changing the temperature 
setting.  To change the temperature setting follow these instructions:
1.   "Wake Up" the temperature indicators by holding down both the 
"COOLER" and "HOTTER" temperature adjustment buttons at 
the same time for one second (see Figure 6).  One or two of the 
temperature indicators will light up.  These indicators will only remain 
on for 30 seconds if no further buttons are pressed.  After 30 seconds 
the control will go back to "Sleep" mode.
2.  Release both of the temperature adjustment buttons.
  A. To decrease the temperature press and release the "COOLER" 
button until desired setting is reached.
  B. To increase the temperature press and release the "HOTTER" 
button until the desired setting is reached.
NOTE: Holding down the button will not continue to lower or raise the 
temperature setting.  The button must be pressed and released for each 
temperature change desired.
SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL TO 
SHUT OFF, TURN OFF THE MAIN MANUAL GAS SHUTOFF VALVE 
TO THE APPLIANCE. SEE FIGURE 1 (G).
CHECKING VENTING
The following steps shall be followed with each appliance connected 
to the venting system placed in operation, while any other appliances 
connected to the venting system are not in operation.
1.  Seal any unused openings in the venting system.
2.   Inspect the venting system for proper size and horizontal pitch, as 
required in the National Fuel Gas Code, ANSI Z223.1/NFPA 54 
or the CAN/CSA-B149.1 Installation codes and these instructions.  
Determine that there is no blockage or restriction, leakage, corrosion 
and other deficiencies which could cause an unsafe condition.
3.  So far as is practical, close all building doors and windows and all 
doors between the space in which the water heater(s) connected 
to the venting system are located and other spaces of the building.  
Turn on all appliances not connected to the venting system.  Turn 
on all exhaust fans, such as range hoods and bathroom exhausts, 
so they shall operate at maximum speed.  Close fireplace dampers.
4.   Follow the lighting instruction.  Place the water heater being 
inspected in operation. Adjust thermostat so appliance shall operate 
continuously.
5.   Test for vent system leakage after 5 minutes of main burner operation.
TEMPERATURE REGULATION
   DANGER
THIS WATER HEATER IS EQUIPPED WITH AN ADJUSTABLE 
THERMOSTAT TO CONTROL WATER TEMPERATURE. HOT WATER 
TEMPERATURES REQUIRED FOR AUTOMATIC DISHWASHING AND 
LAUNDRY USE CAN CAUSE PAINFUL SCALDING WITH POSSIBLE 
SERIOUS AND PERMANENT INJURY. THE TEMPERATURE AT WHICH 
INJURY OCCURS VARIES WITH THE PERSON’S AGE AND THE TIME 
OF THE  EXPOSURE. THE SLOWER RESPONSE TIME OF CHILDREN, 
AGED OR DISABLED PERSONS INCREASES THE HAZARDS TO 
THEM. NEVER ALLOW SMALL CHILDREN TO USE A HOT WATER TAP, 
OR TO DRAW THEIR OWN BATH WATER. NEVER LEAVE A CHILD 
OR DISABLED PERSON UNATTENDED IN A BATHTUB OR SHOWER.
THE WATER HEATER SHOULD BE LOCATED IN AN AREA WHERE 
THE GENERAL PUBLIC DOES NOT HAVE ACCESS. IF A SUITABLE 
AREA IS NOT AVAILABLE, A COVER SHOULD BE INSTALLED OVER 
THE THERMOSTAT TO PREVENT TAMPERING.Suitable covers 
are available from the manufacturer, authorized service agencies or 
distributors. When ordering parts be sure to have the complete water 
heater Model Number, Serial Number and Series Number available. This 
information can be found on the rating label affixed to the water heater.
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 
temperature  setting  be  set  for  the  lowest  temperature  that  satisfies 
your hot water needs. This will also provide the most energy efficient 
operation of the water heater. The water temperature adjustment was 
factory set at the lowest temperature. Pressing the "COOLER" 
 
button decreases temperature and pressing the "HOTTER" 
 button 
increases the temperature.
         Time to Produce
     Display  2nd & 3rd Degree
  Temperature Setting 
 B C D  E F  Burns on Adult Skin
  F  = approx. 180°F (82°C)  Nearly Instantaneous
  E  = approx. 170°F (77°C)  Nearly Instantaneous
  D  = approx. 160°F (71°C)  About 1/2 Second
  C  = approx. 150°F (65°C)  About 1 1/2 Seconds
  B  = approx. 140°F (60°C)  Less than 5 Seconds
  B  = approx. 130°F (54°C)  More than 30 Seconds
 
  =  approx. 120°F (49°C)   More than 5 Minutes
FIGURE 6. 
						

							121. 
Provide complete combustion of gas.
2.  Cause rapid ignition and carryover of flame across entire burner.
3.   Give reasonably quiet operation during ignition, burning and extinction.
4.  Cause no excessive lifting of flames from burner ports.
If preceding burner characteristics are not evident, check for accumulat\
ion 
of lint or other foreign material that restricts or blocks the air openi\
ngs 
to the heater or burner.
  WARNINGSOOT BUILD-UP INDICATES A PROBLEM THAT REQUIRES 
CORRECTION BEFORE FURTHER USE. CONSULT WITH A 
QUALIFIED SERVICE TECHNICIAN.
Should the main burner or burner air openings require cleaning, remove 
the burner and clean with a soft brush. Clean main burner orifice with a 
suitable soft material.  
CHECK FOR GOOD FLOW OF COMBUSTION AND VENTILATING AIR 
TO THE UNIT. MAINTAIN A CLEAR OPEN AREA AROUND THE HEATER 
AT ALL TIMES. DO NOT STORE COMBUSTIBLES OR FLAMMABLE 
LIQUIDS  NEAR  OR AROUND AN APPLIANCE.
CHECKING GAS INPUT
For appliance installation locations with elevation above 2000  ft.(610m) 
refer to HIGH ALTITUDE INSTALLATIONS section of this manual for 
input reduction procedure.
With this heater in operation, determine whether it is receiving the full rated 
input of gas.  This may be done by timing the gas meter and measuring 
gas pressure with a gauge or manometer.  When the heater is operating 
at full capacity (full gas input) it should consume approximately 1 cubic 
foot of gas in the time shown in table 6.
  TABLE 6 
  INPUT CHECK TIME REQUIRED TO CONSUME 1 CU. FT. OF GAS
Use this formula to “clock” the meter.  Be sure that other gas consuming 
appliances are not operating during this interval.
  3,600  X  H  =  Btu/h
     T
  T  =  Time in seconds needed to burn one cubic foot of gas.
  H = Heating value of gas in Btu’s per cubic foot of gas.
  Btuh = Actual heater input rate.
 Example:
  T  =  47.2 seconds/ft
3
 H  =  1,050 Btu/ft3 (natural gas)
  Btuh  =  ?
  3,600  X  1,050  =  75,100 Btu/h (22Kw)
   50.3
Compare the actual input rate to that given on the heater’s rating plate.  
In the example, the full input rate should be 75,000 Btu/h (22 Kw) for 
natural gas.
VENT SYSTEM
Examine the venting system every 6 months for obstructions and/or 
deterioration of vent piping.
6. 
After it has been determined that each appliance connected to the 
venting system properly vents when tested as outlined above, return 
doors, windows, exhaust fans, fireplace dampers and any other gas 
burning appliance to their previous conditions of use.
7.  If improper venting is observed during any of the above tests, the 
venting system must be corrected.
 WARNINGFAILURE TO CORRECT BACK DRAFTS MAY CAUSE AIR 
CONTAMINATION AND UNSAFE CONDITIONS.
HIGH TEMPERATURE LIMIT SWITCH (ECO)
The water heater is equipped with a manual reset type high limit (Energy 
Cutoff) sensor. The high limit switch interrupts the main burner gas flow 
should the water temperature reach 195°F (90°C). The high limit switch 
must be manually reset by turning the power to the water heater off for 5 
seconds then back on and cannot be reset until the water temperature 
drops below 120°F (49°C). It is important that a serviceman be called 
to determine the reason for limit operation and thus avoid repeated 
thermostat resetting.
   WARNINGTHE ON/OFF SWITCH MUST HAVE BEEN IN THE OFF POSITION 
FOR AT LEAST 5 MINUTES.  This waiting period is an important 
safety step.  Its purpose is to permit gas that may have accumulated 
in the combustion chamber to clear.  IF YOU DETECT GAS ODOR AT 
THE END OF THIS PERIOD DO NOT PROCEED WITH LIGHTING. 
RECOGNIZE THAT GAS ODOR, EVEN IF IT SEEMS WEAK, MAY 
INDICATE PRESENCE OF ACCUMULATED GAS SOMEPLACE IN 
THE AREA WITH RISK OF FIRE OR EXPLOSION.  SEE THE FRONT 
PAGE FOR STEPS TO BE TAKEN.
SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL TO 
SHUT OFF, TURN OFF THE MANUAL GAS CONTROL VALVE TO 
THE APPLIANCE.
SERVICE INFORMATION
The installer may be able to observe and correct certain problems 
which may arise when the unit is put into operation.  HOWEVER, it is 
recommended  that  only  qualified  servicemen,  using  appropriate  test 
equipment, be allowed to service the heater.
FOR YOUR SAFETY AND SATISFACTORY OPERATION, IT IS 
RECOMMENDED THAT THIS HEATER BE CHECKED ONCE A YEAR 
BY A COMPETENT SERVICE PERSON.
USERS OF THIS WATER HEATER SHOULD BE AWARE THAT GAS 
COMPONENTS WEAR OUT OVER A PERIOD OF TIME.  THE GAS 
CARRYING COMPONENTS OF THIS  WATER HEATER  SHOULD 
BE INSPECTED FOR PROPER OPERATION PERIODICALLY BY A 
QUALIFIED SERVICE TECHNICIAN.
MAIN BURNER AND IGNITER
Check main burner (figure 7) at least every 6 months for proper 
flame  characteristics.    The  main  burner  should  display  the  following 
characteristics:
FIGURE 7. MAIN BURNER AND IGNITER ASSEMBLY
Type of Gas BTU Per Cu. Ft. Time Required To Con-
sume 1 Cu. Ft. of Gas
Natural 105050.3 Seconds
BURNER HEAD
ASSEMBLY
BURNER TUBEASSEMBLY
H.S.I.
ASSEMBLY 
						

							13
BLOWER MAINTENANCE
For safety and satisfactory operation it is recommended that the blower 
be checked once a year by a competent service person.
1. MOTOR - The motor is factory oiled and sealed and requires no 
further maintenance.
2.  WHEEL - Wheel must be clean of soot, ash or any other coating 
which inhibits either rotation or air flow.  Remove all foreign material 
from vent system.
3.   The pressure switch is inside the blower control box and is connected 
to the blower housing with a tube.  This tubing should be soft and 
pliable and show no sign of deterioration. 
RELIEF VALVE
At least once a year the temperature and pressure relief valve 
should be checked to ensure that it is in operating condition.  
(During manual operation of this valve, avoid any contact with hot 
water and take preventive steps for water damage).  Lift the lever 
at the top of the valve several times until the valve seats properly 
and operates freely.
  WARNING
THE WATER PASSING OUT OF THE VALVE DURING THIS CHECKING 
OPERATION MAY BE EXTREMELY HOT.  AVOID CONTACT AND 
DISCHARGE SAFELY TO PREVENT WATER DAMAGE.
If the temperature and pressure relief valve on the heater discharges 
periodically or continuously, a problem exists.  This may be due to 
unusually high water temperatures or pressures in the system, or to a 
faulty relief valve.  Contact your dealer or a qualified service technician 
to find the cause of the problem and to correct it.  This may also be due 
to thermal expansion in a closed water supply system.  Contact the water 
supplier or local plumbing inspector on how to correct this situation.  DO 
NOT PLUG THE TEMPERATURE AND PRESSURE RELIEF VALVE.
  WARNING
SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL TO 
SHUT OFF, TURN OFF THE MANUAL GAS CONTROL VALVE TO THE 
APPLIANCE.
HOT WATER ODOR
On occasion, hot water may develop a strong odor.  If this occurs drain 
the heater completely, flush thoroughly, and refill.  If the problem persists, 
chlorination of the heater and replacement of the factory installed 
magnesium anode with aluminum anode may correct the condition.
Occasionally water softener companies recommend removal of heater 
anodes for odor reasons.
 CAUTION 
Unauthorized removal of heater anode will void the warranty.  Replace 
the anode as necessary to maintain corrosion protection.  For further 
information contact your dealer. 
WINTER PROTECTION
In regions where freezing weather is encountered, all water must be 
drained from unit and piping when out of service (water shut off).  Drain 
valve must be left open until unit is returned to service.
REPLACEMENT PARTS
Replacement parts may be ordered from the manufacturer, 
authorized service agencies or distributors. When ordering parts 
be sure to have the complete water heater Model Number, Serial 
Number and Series Number available. This information can be 
found on the rating label affixed to the water heater. Refer to the 
parts list included with the water heater from the factory for more 
information or call the parts department or technical support phone 
number listed on the back cover of this manual for further assistance.
PREVENTIVE MAINTENANCE
RECOMMENDED PROCEDURE FOR PERIODIC 
REMOVAL OF LIME DEPOSITS FROM TANK TYPE  COMMERCIAL WATER HEATERS
FIGURE 8.
The amount of calcium carbonate (lime) released from water is in direc\
t 
proportion to water temperature and usage, see chart.  The higher the 
water temperature or water usage, the more lime deposits are dropped 
out of the water.  This is the lime scale which forms in pipes, heaters 
and on cooking utensils.
Lime accumulation not only reduces the life of the equipment but also 
reduces efficiency of the heater and increases fuel consumption.
The usage of water softening equipment greatly reduces the hardness 
of the water.  However, this equipment does not always remove all of 
the hardness (lime).  For this reason it is recommended that a regular 
schedule for deliming be maintained.
The time between cleaning will vary from weeks to months depending 
upon water conditions and usage.
UN•LIME
® and the booklet may be obtained through your dealer 
or distributor.
DELIMING SOLVENTS
UN•LIME  is  recommended  for  deliming.  UN•LIME  is  a  patented  food 
grade acid which is safe to handle and does not create the harmful 
fumes which are associated with other products.
UN•LIME may be obtained from your dealer, distributor or water heater 
manufacturer. Order Part Number 9005416105, 1 gallon, packed 4 
gallons per case or Part Number 9005417105, 5 gallon container.
NOTE:  Un•Lime  is  not  available  for  use  in  Canada.  Hydrochloric base 
acids are not recommended for use on glass-lined tanks.
  CAUTION
Observe handling instructions on label of product being used. 
						

							14
TANK CLEANOUT PROCEDURE
The following practices will ensure longer life and enable the unit to 
operate at its designed efficiency:
1. Once a month the heater should be flushed.  Open the drain valve 
and allow two gallons of water to drain from the heater.  Inlet water 
valve should remain open to maintain pressure in tank.
2.  A cleanout opening is provided for periodic cleaning of the tank.  
Gas must be shut off and heater drained before opening cleanout.
To clean heater through cleanout opening, proceed as follows:
1.  Drain heater.
2.  Remove outer cover plate from lower side of heater jacket.
3.  Remove six (6) hex head screws securing tank cleanout plate and 
remove plate.
4.   Remove lime, scale, or sediment using care not to damage the glass 
lining.
5.  Inspect cleanout plate gasket, if new gasket is required.
6.  Install cleanout plate.  Be sure to draw plate up tight by tightening 
screws securely.
7.  Replace outer jacket cover plate.
In some water areas the sediment might not be removed by this method 
and may result in the water heater making rumbling or boiling noises.  To 
dissolve and remove these more stubborn mineral deposits, UN•LIME 
Professional Delimer should be used.
 
FIGURE 9
FLO-JUG METHOD OF DELIMING
The  Flo-Jug  is  the  standard  5  gallon  container  for  UN•LIME  -or-  it  is 
available as a deliming kit with hose and fittings.  Contact your dealer 
or distributor.
Figure 9 illustrates most of the following steps.
1.  The heater should be prepared for deliming as described in the 
“Why? When and How” booklet.  The relief valve may also be delimed 
at this time. 2. 
With the Flo-Jug upright:
  • Take off cap, remove cover under opening and install 3/4" x 4" 
pipe nipple.
  •  Drill or punch a 3/16" vent hole in handle.  A stainless steel screw 
is included with the Flo-Jug kit.  This screw is to be installed in 
the vent hole when Flo-Jug is not in use.
  • Remove drain valve from heater and insert a 3/4" x 4" nipple.
  •  Connect and clamp 1" I.D. x 3" hose to Flo-Jug and heater nipple.
3.  Lift  the  Flo-Jug  to  the  POUR  POSITION and  permit  the  UN•LIME 
to flow into the heater as rapidly as possible.
  • Be sure to keep the vent just above the liquid level.
4.  Place the Flo-Jug in the DELIME POSITION.
  • It may be necessary to place the empty jug on its carton to trap 
the solution in the heater.
  • Allow the UN•LIME to attack the water scale for 5 minutes.
5.  Lower the Flo-Jug to the DRAIN POSITION and allow the UN•LIME 
to flow out of the heater as rapidly as possible.
  • Observe the vent holes and elevate the jug slightly if there is a 
possibility of spillage.
  • Deliming  activity  is  indicated  by  foaming  on  the  surface  of  the 
solution.
6.  Continue the deliming process:
  •  Raise jug to POUR POSITION.  Allow solution to flow into heater.
  • Place  jug  in  DELIME  POSITION  for  5  minutes.  Solution  is  at 
work in heater.
  • Lower jug to DRAIN POSITION and allow solution to flow out. 
Observe foaming.
7.  After one hour, or earlier if the deliming activity (foaming) stops, 
inspect the tank interior.
  • Drain the UN•LIME back into jug, DRAIN POSITION, and then 
stand jug in DELIME POSITION.
  • Remove  the  clamp,  hose  and  the  pipe  nipple  from  heater 
drain opening.
  • Observe  interior  through  opening  -  a  small  flashlight  may  be 
used effectively.
  •  If the interior still shows water scale, the deliming process should 
be continued.
  • To check UN•LIME for continued use or reuse, place some lime 
scale or white chalk into a glass with a small amount of solution.  If 
the material is vigorously dissolved by the solution, the UN•LIME 
can  be  reused.    If  not,  the  UN•LIME  has  been  weakened  and 
should  be replaced.
8.  When deliming has been completed, the heater should be flushed 
for 3 to 5 minutes with fresh water.
  • Remove the deliming equipment, install the drain valve, open the  
						

							15
cold water inlet line and allow water to flow through heater and out 
drain valve.  Don’t forget to plug vent and cap opening in Flo-Jug.
9.  When flushing is completed:
  • Fill heater being certain to expel air from tank through a nearby 
hot water faucet or, if removed, the relief valve opening.
  • The heater relief valve can be washed in UN•LIME if it is limed.
  • Replace relief valve if removed for deliming.
  • Restore gas, oil or electrical supply to heater.
  • Check for water leakage.
10.  Flo-Jug cleanup:
  • Allow scale to separate from UN•LIME and settle on bottom of 
Flo-Jug.
 
  • Pour off UN•LIME into plastic container and check for reuse.
  • Rinse sediment from Flo-Jug.
CHECKLIST
Before contacting your dealer, check the water heater to see if the appa\
rent 
malfunction is caused by some external fault. Consulting this checklist 
may eliminate the need for a repair call and restore hot water service.
NOT ENOUGH OR NO HOT WATER
1.  Look  for leaking or open hot water faucets.  Check for excessive 
usage.
2.  Your gas company can check the gas input to the heater to see that 
it is correct.  An underfired heater will not produce hot water at its 
normal recovery rate.
3.  If the heater was installed when incoming water temperatures were 
warm, colder incoming temperatures will create the effect of less 
hot water.
4.  The thermostat water temperature adjusting dial may be set too low.
5.  If you cannot determine the cause of the problems, contact your 
dealer.
WATER TEMPERATURE IS TOO HOT
1.  The thermostat water temperature adjusting dial may be set too high.
2.  If lowering control setting does not reduce the water temperature   
contact your dealer.
GAS SMELL AT THE HEATER
1.  Close the main shutoff valve in the gas supply pipe near the heater, 
see Figure 5 on page 9.  The thermostat includes a gas control (top 
knob) which can also be closed.
2.  Call your gas company.
WATER LEAKAGE IS SUSPECTED
1.  Check to see if the heater drain valve is tightly closed.
2.  The apparent leakage might be condensation.  In warm or humid 
locations, condensation can accumulate and run from within the 
heater or its piping.  
• When a water heater is first installed and filled, the bottom of the 
tank might condense water.  The water accumulation, if excessive, 
can drip into the floor shield.  Also, during normal operation there 
may be occasions when large quantities of water are drawn, 
chilling the tank bottom.  This too can result in condensation.
  • Condensation, appearing in the vent pipe (water dripping from 
draft diverter) during heater operation is evidence of poor vent 
action.  Possible causes are too long a vent pipe or improper 
chimney operation.
3.  If the leakage is from the temperature and pressure relief valve or 
its discharge pipe, it may represent a normal condition.  However,   
see RELIEF VALVE section on page 7.  DO NOT PLUG THE 
TEMPERATURE AND PRESSURE RELIEF VALVE.  Also, the   
leakage could be due to unusually high water pressures or 
temperatures in the system, or to a faulty relief valve.  Your dealer 
or a qualified service technician should be called to determine the 
cause of the problem and to correct it.
4.  If you cannot identify or correct the source of water leakage:
  •  Close the main shutoff valve in the gas supply pipe at the heater. 
See Figure 5, page 9.
  • Close the valve which feeds water to the cold water inlet at the 
top of the heater.
  • Contact your dealer.
WATER HEATER MAKES SOUNDS
1.   Occasional excessive condensation, as explained under LEAKAGE, 
can cause a sizzling sound as the moisture is vaporized by the gas 
flame. This is a normal sound and may be disregarded.
2.   Sediment and water scale accumulations may cause rumbling 
noises. See MAINTENANCE or contact your dealer for details of 
flushing the heater.
3.  If you cannot identify or remedy the condition, contact your dealer.
CONDENSATION
Water vapor can condense on the cooler surfaces of the tank forming 
droplets, these drip into the fire or run out on the floor.  This is common at 
the time of startup after installation, during periods of time when incoming 
water is very cold, or the heater may be undersized for the requirements\
.
Droplets from the bottom of the flue may be due to corrosive combustion 
products or improper vent.  Check with your dealer for more information.\
ANODE
The anode rod is used to protect the tank from corrosion.  Most hot wate\
r 
tanks  are  equipped  with  an  anode  rod.    The  submerged  rod  sacrifices 
itself to protect the tank.  Instead of corroding the tank, water ions a\
ttack 
and eat away the anode rod.  This does not affect the water’s taste o\
r 
color.  The rod must be maintained to keep the tank in operating condition.
Anode deterioration depends on water conductivity, not necessarily 
water condition.  A corroded or pitted anode rod indicates high water 
conductivity and should be checked and/or replaced more often than 
an anode rod that appears to be intact.  Replacement of a depleted 
anode rod can extend the life of your water heater.  Inspection should 
be  conducted  by  a  qualified  technician,  and  at  a  minimum  should  be 
checked annually after the warranty period.
A hydrogen sulfide (rotten egg) odor may result if water contains high 
sulfate and/or minerals.  Chlorinating the water supply should minimize 
the problem.  (See EXTENDED NON-USE PERIODS). 
						

							16
NOTE: Anode must remain installed (except for inspection) to 
avoid shortening tank life.  See LIMITED WARR ANTY.  Replace 
as necessary.
SERVICE AND REPAIR
The water heater requires no special care other than the normal 
maintenance as noted above.  If you are having a problem with your 
water heater, before calling for service please refer to the following 
TROUBLESHOOTING sections.  If service becomes necessary, 
contact your dealer, installer or an authorized service agent.  Do not 
attempt to repair the water heater yourself.  Any work performed by 
unauthorized personnel may void the warranty. 
Please be sure to provide the following information when writing or 
e-mailing:
  • Model Number
  • Serial Number
  • Date of Original Purchase
  • Date Problem Originated
  • Explanation of Problem
Also, please be sure to include a daytime telephone number.
TROUBLESHOOTING
Water heaters may exhibit problems that are unrelated to a 
malfunction of the water heater itself.  The following information and 
tables may serve to answer your question about a problem that you 
are having without having to call a service agent.
For your safety, water heater service should be performed only 
by a qualified service technician.  Read the GENERAL SAFETY 
INFORMATION section first.
WATER HEATING CYCLE
(GAS AND ELECTRIC POWER ARE ON,“OFF/ON” SWITCH IS ON)
1)  CALLS FOR HEAT
  A)  THERMOSTAT SENSES NEED FOR HEATING WATER
  B)  CONTACTS CLOSE IN THERMOSTAT, POWER (115 VAC)  
      FLOWS TO BLOWER MOTOR
2)  BLOWER MOTOR ROTATES BLOWER WHEEL
  A)  BLOWER WHEEL SPEED INCREASES
  B)  WHEEL SPEED INCREASES, AIR PRESSURE SWITCH         
CONTACTS CLOSE 
3)  120 VAC FLOWS TO HOT SURFACE IGNITER
NOTE:  THE CONTROL MODULE ON THIS UNIT WILL TRY A 
MA XIMUM OF THREE TIMES TO LIGHT THE UNIT.  CYCLE CAN 
BE RESTARTED AT ANY TIME BY TURNING OFF SWITCH AND 
THEN TURNING BACK ON.  IF UNIT HAS GONE THROUGH 
THREE CYCLES AND DID NOT LIGHT, THEN REPAIRMAN 
SHOULD BE CALLED TO CHECK OPER ATION OF HEATER.
4)  MAIN BURNER IGNITES
  A)  GAS FLOWS TO MAIN BURNER PORTS AND IS IGNITED
5)  GAS VALVE SENSES BURNER FLAME  
 
6)  BURNER HEATS WATER
  A)  BURNER HEATS WATER TO THERMOSTAT SETTING
  B)  CONTACTS IN THERMOSTAT OPEN,
  C)  CYCLE IS COMPLETED 
						

							17
TROUBLESHOOTING 
For your safety, water heater service should be performed only by a qualified service technician.  Read the GENERAL SAFETY INFORMATION section first. 
PROBLEM POSSILBE MALFUNCTION SERVICE TO BE PERFORMED
NOT ENOUGH OR NO HOT WATER 1) Blower will not run.
A) "ON/OFF" control switch turned off. Turn switch to the on position.
B) Blower unplugged. Plug blower back into 115 vac. outlet.
C) No power at outlet. Repair service to outlet.
D) "ON/OFF" switch defective. Replace switch.
E) Control harness defective. Replace control harness.
F) Blower motor defective. Replace blower and motor.
2) Blower running, burner not on Replace switch.
A) Fan not running fast enough to close 
    air switch contacts. Check for low voltage, less than 102 vac., 
have service checked and repaired.
B) Air pressure switch defective. Replace switch.
C) Gas valve defective. Replace gas control valve/ thermostat.
D) Control harness defective. Replace harness.
E) Igniter defective. Replace ignitor.
F) Unit has completed three trials to light 
    and fail. Reset cycle by turning switch off and then 
back on. If unit does not light in three tri-
als, contact a qualified person for service.
3) Thermostat problems A) Thermostat set too low. Set temperature control higher.
B) Thermostat or ECO defective. Replace gas control valve/thermostat.
C) High limit control circuit open. Replace high limit control.
4) Others A) Heater undersized. Reduce hot water usage.
B) Low gas pressure. Contact a qualified person for service.
C) Incoming water is unusually cold. Allow more time for heater to re-heat.
D) Leaking hot water pipes or fixtures. Have plumber check and repair leaks.
CONDENSATION A) Water on the floor under heater. See "Condensation"
WATER LEAKS Improperly sealed, hot or cold supply 
connections, relief valve, drain valve or 
thermostat threads.
Turn off heater & water, repair unit.
Leakage from other appliances or water 
lines. Inspect other appliances near water 
heater.
Condensation of flue products. Refer to "CONDENSATION"
LEAKING T&P VALVE Thermal expansion in closed water sys-
tem
Install thermal expansion tank (DO NOT 
PLUG T&P VALVE)
Improperly seated valves Check relief valve for proper operation 
(DO NOT PLUG T&P VALVE)
HOT WATER ODORS OR COLOR
(Refer to CATHODIC PROTECTION) High sulfate or mineral content in water 
supply or iron or sulfate reducing bacteria 
in water supply Drain and flush heater thoroughly, chlori-
nate, refil and flush again then chlorinate 
water supply. 
						

							18
TROUBLESHOOTING GUIDELINES
TROUBLE SHOOTINGPlease check guidelines below.  For your safety, water heater service should be performed only by a qualified service technician.  Read the GENERAL SAFETY INFORMATION section first.
INTELLI-VENT TROUBLESHOOTING CHART - USER CONTROL
    PROBLEM    SOLUTION
   Inadequate or no earth ground   1. Ensure the wall outlet is properly grounded.
  1  sensed by the Intelli-Vent™
    control.  2. Ensure all ground connections/wires on the 
       water heater are secure.
         Power supply to Intelli-Vent™  1. Ensure the wall outlet is properly wired.
  2  control has reversed polarity or a
    high resistance to earth ground.  2. Ensure all internal 120 VAC wiring connections and 
       wiring harness have no reversed wires. 120 VAC
       “hot” wire must connect to the on/off switch.
      3. Ensure the wall outlet is properly grounded.
 4. Ensure all ground connections/wires on the water 
   heater are secure.
    Pressure switch circuit remaining 1. Ensure air pressure switch circuit wiring is correct
  3  closed for more than 5 seconds   and the air pressure switch is not jumpered.
    after heating cycle begins.
   Blower does not start.  2. Secure power to water heater, check continuity of air
       pressure switch contacts with wires disconnected.
   Service Note: 
    Disconnect power - disconnect one    A  If pressure switch contacts show continuity (closed
    wire from the air pressure switch      circuit) replace the pressure switch.
    or the vent temperature limit
    switch. Turn power back on -   B  If pressure switch contacts are open and all wiring
    blower should start.     is correct - turn the power off for 10-20 seconds
         then on again to clear the error code - if the error
         code persists replace the Intelli-Vent™ control.
       Pressure switch circuit remains open  1. Ensure the blower is running - check for 120 VAC to
  4  longer than 5 seconds after the blower    the blower when the heating cycle begins, check the
    is energized.   wiring. If the control does not energize the blower -
       replace the Intelli-Vent™ control. If the blower fails to
   Blower may run continuously in     start when energized - replace the blower assembly.
   this condition. 
      2. Ensure the air pressure switch sensing tube is proper ly 
       connected - not kinked or damaged.
      3. Check continuity of vent temperature limit switch - replace
       switch if contacts remain open under 160ºF (71°C).
    
      4. Ensure the correct size of vent pipe (2”, 3”, 4”) was used
   Service Note:   per installation manual for vent length. Ensure maximum
    To learn more about performing Air    number of elbows or equivalent feet of vent pipe has not
    Pressure Switch tests visit our web    exceeded maximum limits.
    site www.hotwater.com to download
    technical bulletin A-023-06 Air Pressure  5. Ensure there are no obstructions in the vent pipe.
   Switches. 
      6. Check air pressure switch performance - check pressure
       with a digital manometer - check continuity of contacts.
       (see service note in left column) If the switch proves   
       defective - replace the air pressure switch and or the
       blower assembly as required.
      7. If air pressure switch performance test results prove
       the air pressure switch is working properly and error
       code 4 persists - replace the Intelli-Vent™ control.
    The Intelli-Vent™ control has detected  1. Check wiring to the hot surface ignitor - replace ignitor
  5  an open ignitor circuit.   assembly if wiring is damaged or worn.
    
   Service Note:  2. Check ignitor assembly plug and the socket on the
    The resistance (ohms) of a hot surface    Intelli-Vent™ body for good connection. Replace
    ignitor will increase over time. If the    ignitor assembly and/or control if necessary.
    resistance at room temperature is near   
    18.8 ohms - consider replacing the ignitor  3. Check resistance of ignitor at room temperature 77ºF 
    as a preventative measure.   (25°C) at the plug end. Replace ignitor if resistance
       is not within 11.5 and 18.8 ohms at room temperature.
    
      4. If results from the above tests were good and error
       code 5 persists - replace the Intelli-Vent™ control.
B  C D  E F
#       LED STATUS
WATER HEATER CONTROL
B C D  E F
B C D  E F
B C D  E F
B C D  E F 
						

							19
TROUBLESHOOTING GUIDELINES
TROUBLE SHOOTINGPlease check guidelines below.  For your safety, water heater service should be performed only by a qualified service technician.  Read the GENERAL SAFETY INFORMATION section first.
INTELLI-VENT TROUBLESHOOTING CHART - USER CONTROL
PROBLEMSOLUTION
Ignition/ame failure.
6 The water heater has reached th e
maximum number of retries and is
currently lockedoutfor one hour .
Cycle the power to the water heater
of f and on to reset.
Service Note: Ther esistance( ohms)ofahot surface
ignitor willincreas eovert ime. Ifth e
resistancea troom temperaturei snear
18 .8 ohms  - consider replacing the ignitor
as a preventative measure.
Self diagnostic tests have found a problem 1.Tu rn the power of f for 10-20 seconds then on again to
7w ith the gas valve driver circuit, interna lclear these error codes .
microprocesso r, or other internal circuits.
2.If any of these error codes persist or cannot be cleared-
replace the Intelli-V ent™ control.
8
9
Flame signal has been sensed out of 1.Tu rn the power of f for 10-20 seconds and then on again
10 proper sequence. to clear this error code.
2. Replace the Intelli-V ent™ control if this error code persists .
Wa ter temperature in the tank has 1.Tu rn the power of f for 10-20 seconds then on again
11  exceeded 195°F(91°C)and has to clear this error code.
activated the ECO. 2. Replace the Intelli-V ent™ if the error code persists.
The self diagnostic check detected one 
12
13
14 or both of the temperature adjust buttons
are stuck.
The self diagnostic test has detected th e
watert emperature sensor(thermistor)i s
either open or shorted. 2.Replace the Intelli- Vent™ control if this error code persist .
#       LED STATUS
WA TERH EATERC ONTROL
B C D  E  F
B C D  E  F
B C D  E  F
B C D  E  F
B C D  E  F
B C D  E  F
B C D  E  F
B C D  E  F
B C D  E  F
1. Press and release temperature adjust buttons. If above 
 a ction does not clear error, control will continue to regulate 
  water temperature at last setting. However, settings will no  
 longer be adjustable - the control should be replaced.
1.  Turn power off for 10-20 seconds then on again to
 clear this error code. 4.  Ensure the flame sensor is clean - use ultra fine steel
  wool or Scotch-Brite™ pad to clean flame sensor .
5.  Ensure the hot surface ignitor is positioned to provide
 consistent ignition.
6.  Check for any cracks in ignitor assembly cerami c
  insulators - replace ignitor assembly if damaged.
7.  Check resistance of ignitor at room temperature (77ºF)
  (25°C) at the plug end. Replace ignitor if resistance is
  not within 11.5 and 18.8 ohms at room temperature .
8.  Ensure correct size of vent pipe (2”, 3”, 4”) was used per 
 installation manual for vent length. Using larger pipe than required   may cause excessive air turbulance in combustion chamber .
1. Turn off power to the water heater.   
2. Insure black resistor wire is not cut, missing, and is installed 
  between pins 3 & 4 of ignitor assembly plug. Replace ignitor  
 a ssembly if damaged or defective.   
3. Unplug ignitor assembly plug from control. Check resistance   of black resistor wire between pins 3 & 4 with an ohm meter . 
  3.1 If reading taken is less than 2000 (5000 for date code 0617 
  through 0709) or more than 1.7 million ohms, replace ignitor  
 a ssembly . 3.2 If reading taken is between 2000 (5000 for date 
 c ode 0617 through 0709) and 1.7 million ohms, replace 
  Intelli-  Vent™ control.  
Service Note: Raised ridges on ignitor assembly plug identify  
#1, #2, and #3 pins.   The four-digit date code can be found on  
side of the controller .
Self-diagnostic test found a problem with black 
resistor wire on the ignitor assembly plug; resistor  
wire is open or shorted.
Service Note: To perform this test ohm meter 
used must be capable of reading up to 2,000,000 
ohms. Unless ohm meter used has an auto-range 
f eature resistance should be checked twice. First 
r eading will be taken using an ohms scale above 
1,700,000 ohms. Second reading is taken using o hms scale just above 2,000 or 5,000 ohms .
2. Low supply voltage - should be 115 -125 VAC.
3. Ensure flame sensor is making good contact with burner flame, ensure flame is steady see #8 below.1. 
Gas supply 
is turned of f-pressure too low . Ensure supply and 
 m anifold gas pressures are within requirements in installation 
 manual.  Manifold  gas pressure  is non-adjustable if pressure is  
  off by more than 0.3”  W.C. (75 Pa) replace Intelli- Vent™ control. 
						

							20
TROUBLESHOOTING GUIDELINES
TROUBLE SHOOTINGPlease check guidelines below.  For your safety, water heater service should be performed only by a qualified service technician.  Read the GENERAL SAFETY INFORMATION section first.
INTELLI-VENT TROUBLESHOOTING CHART - USER CONTROL
PROBLEMSOLUTION
15
#       LED ST ATUS
B  C D  E  F1. Turn off power to the water heater.   
2. Unplug the ignitor assembly plug from the control. Check 
 t he resistance of the black resistor wire between pins  
  3 & 4 with an ohm meter. 2.1 If the reading taken is more  
 t han 100,000 (50,000 for data code before 0616; 70,000  
  for data code 0617 through 0709) ohms replace the ignitor 
 a ssembly. 2.2 If the reading taken is less than 100,000 
 ( 50,000 for data code before 0616; 70,000 for data code  
 0 617 through 0709) ohms replace Intelli-Vent™ control.  The self-diagnostic test determined resistanc e
of the black resistor wire on ignitor assembly  plug is not within tolerance. 
1. Ensure air pressure switch hose is not kinked or clogged;  
  ensure the blower housing is clear of any condensation.   
2. Check vent temperature limit switch - if it is determined  
 t hat the vent temperature limit switch is opening its 
 c ontacts at normal operating temperatures during heating 
 c ycle - replace the vent temperature limit switch.   
3. Ensure water heater is not over-firing. 3.1 Check burner 
  orifice size and ensure the correct orifice is installed; 
 r eplace as necessary. 3.2 Check manifold gas pressure  
 a nd ensure it is within
 0.3” W.C. (75 Pa) of listed rating on
   Intelli-Vent™ control valve. Manifold gas pressure is  
 n on-adjustable, if manifold gas pressure is off by more 
 t han  
0.3” W.C. (75 Pa), replace the Intelli-Vent™ control.   
4. Ensure condensate lines are not obstructed. Check and 
 c lear all condensate lines including the floor condensate  
  drain line.
Air pressure switch circuit is opening 
r
epeatedly during one heating cycle. May be 
c aused by air pressure switch and/or the v ent 
temperature limit switch (these two switches  are wired together in a “series” circuit).
16B C D  E  F
WATER HEAT ER CONTROL