A.O. Smith BL-80 - Temperature Regulation; DANGER BURN Hazard and Scald Prevention; Setting the Thermostat and Mixing Valves; For Your Information

19
START UP CONDITIONS
DRAFT HOOD OPERATION
Check draft hood operation by performing a worst case
depressurization of the building. With all doors and windows
closed, and with all air handling equipment and exhaustfans
operating such as furnaces, clothes dryers, range hoods and
bathroomfans,amatchameshouldstillbedrawnintothedraft
hoodofthewaterheaterwithitsburnerring.Iftheameisnot
drawn toward the draft hood, shut off water heater and make
necessaryairsupplychangestocorrect.
CONDENSATION
Whenever the water heater is filled with cold water, some
condensatewillformwhiletheburnerison.Awaterheatermay
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30°F(16.7°C).Ifyouexperiencethistypeofuse
you should consider using lower temperature settings to reduce
scaldhazards.
Any water heater’s intended purpose is to heat water. Hot water
isneededforcleansing,cleaning,andsanitizing(bodies,dishes,
clothing).Untempered hot water can present a scald hazard.
Dependingonthetimeelement,andthepeopleinvolved(adults,
children, elderly, inrm, etc.)scalding may occur at different
temperatures.
HOTTERWATERCANSCALD:Waterheatersareintendedtoproduce
hotwater.Waterheatedtoatemperaturewhichwillsatisfyspace
heating,clotheswashing,dishwashing,andothersanitizingneeds
canscaldandpermanentlyinjureyouuponcontact.Somepeople
aremorelikelytobepermanentlyinjuredbyhotwaterthanothers.
Theseincludetheelderly,children,theinrm,orphysically/mentally
handicapped.Ifanyoneusinghotwaterinyourhometsintooneof
thesegroupsorifthereisalocalcodeorstatelawrequiringacertain
temperaturewateratthehotwatertap,thenyoumusttakespecial
precautions. In addition to using the lowest possible temperature
settingthatsatisesyourhotwaterneeds,ameanssuchasamixing
valve should be used at the hot water taps used by these people or
atthewaterheater.Mixingvalvesareavailableatplumbingsupplyor
hardwarestores,seeFigure6.Followmanufacturer’sinstructionsfor
installationofthevalves.Beforechangingthefactorysettingonthe
thermostat,readthe“TemperatureRegulation”sectioninthismanual,
seeFigures17and18.
TEMPERATURE REGULATION
FOR YOUR INFORMATION
appeartobeleakingwheninfactthewateriscondensation.This
usuallyhappenswhen:
a.Anewwaterheaterislledwithcoldwaterforthersttime.
b.Burninggasproduceswatervaporinwaterheaters,particularly
highefciencymodelswhereuetemperaturesarelower.
c.Largeamountsofhotwaterareusedinashorttimeandthe
rellwaterinthetankisverycold.
Moisturefromtheproductsofcombustioncondenseonthecooler
tanksurfaces and form drops of water which may fallonto the
burnerorotherhotsurfacestoproducea“sizzling”or“frying”noise.
Excessive condensation can cause pilot outage due to water
runningdownthefluetubeontothemainburnerandputtingout
the pilot.
Neverallowsmallchildrentouseahotwatertap,ortodrawtheirown
bathwater.Neverleaveachildorhandicappedpersonunattended
in a bathtub or shower.
NOTE:Awatertemperaturerangeof120°F-140°F(49°C-60°C)is
recommendedbymostdishwashermanufacturers.
Thethermostatofthiswaterheaterhasbeenfactorysetatitslowest
position (PILOT LIGHTING). It is adjustable and must be reset to
the desired temperature setting to reduce the risk of scald injury.
Themark(
)indicativeofapproximately120°F(49°C)ispreferred
startingpoint.SomeStateshavearequirementforalowersetting.
Turn the water temperature dial clockwise (
 ) to decrease the
temperature,orcounterclockwise(
)toincreasethetemperature.
Shouldoverheatingoccurorthegassupplyfailtoshutoff,turnoffthe
manualgascontrolvalvetothewaterheater.
FIGURE 17.
Temperature Time to Produce 2nd & 3rd
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
A = APPROX.130°F (54°C) About 30 seconds
= APPROX.120°F (49°C) More than 5 minutes
LOW = APPROX.100°F (37.8°C) - - - - - - - -
Setting Degree Burns on Adult Skin
VERY HOT = APPROX. 181°F (83°C)
FIGURE 18.