A.O. Smith BL-80 - Operational Conditions; Checking Gas Input Rate; Smelly Water Causes and Solutions; Hydrogen Gas in Hot Water Faucets

20
CHECKING GAS INPUT
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5.
TABLE 5. INPUT CHECK TIME REQUIRED
TO CONSUME 1 CU. FT. OF GAS
Model Type of Gas
BTU Per
Cu. Ft.
Approx. Time Required To
Consume 1 Cu. Ft. of Gas
BL-80
BL-100
Natural 1050 50.3sec.
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/Hr
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.
 Btu/Hr=Actualheaterinputrate.
 Example:
 T=50.3seconds/ft
3
 H=1,050Btu/ft
3
(naturalgas)
 Btu/Hr=?
3,600X1,050=75,100Btu/Hr(22.0kW)
50.3
Comparetheactualinputratetothatgivenontheheater’srating
plate.Intheexample,theBL-100’sfullinputrateshouldbe75,100
Btu/Hrfornaturalgas.
Because of the suddenness and amount of water, condensation
watermaybediagnosedasa“tankleak”.Afterthewaterinthetank
warmsup(about1-2hours),theconditionshoulddisappear.
Do not assume the water heater is leaking until there has been
enoughtimeforthewaterinthetanktowarmup.
Anundersizedwaterheaterwillcausemorecondensation.Thewater
heatermustbesizedproperlytomeetthefamily’sdemandsforhot
waterincludingdishwashers,washingmachinesandshowerheads.
Excessivecondensationmaybenoticedduringthewinterandearly
springmonthswhenincomingwatertemperaturesareattheirlowest.
Goodventingisessentialforagasredwaterheatertooperateproperly
aswellastocarryawayproductsofcombustionandwatervapor.
SMOKE/ODOR
Itisnotuncommontoexperienceasmallamountofsmokeandodor
duringtheinitialstart-up.Thisisduetoburningoffofoilfrommetal
parts, and will disappear in a short while.
STRANGE SOUNDS
Possiblenoisesduetoexpansionandcontractionofsome metal
partsduringperiodsofheat-upandcool-downdonotnecessarily
representharmfulordangerousconditions.
Condensationcausessizzlingandpoppingwithintheburnerarea
duringheatingandcoolingperiodsandshouldbeconsiderednormal.
See“Condensation”inthissection.
OPERATIONAL CONDITIONS
SMELLY WATER
Ineachwaterheaterthereisinstalledatleastoneanoderodfor
corrosionprotectionofthetank.Certainwaterconditions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.Thisodorisderivedfromhydrogensuldegasdissolved
inthewater.Thesmellistheresultoffourfactorswhichmustallbe
presentforthe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
modelsbyreplacingtheanode(s)withoneoflessactivematerial,
andthenchlorinatingthewaterheatertankandallhotwaterlines.
Contactthelocalwaterheatersupplierorservicetechnicianfor
furtherinformation concerning an AnodeReplacement Kit and
thischlorinationtreatment.
Ifthesmellywaterpersistsaftertheanodereplacementandchlorination
treatment,wecanonlysuggestthatchlorinationoraerationofthewater
supplybeconsideredtoeliminatethewaterproblem.
Do not remove the anode leaving the tank unprotected. By doing
so, all warranty on the water heater tank is voided.
“AIR” IN HOT WATER FAUCETS
HYDROGEN GAS: Hydrogen gas can be produced in a hot
watersystemthathasnotbeenusedforalongperiodoftime
(generally two weeks or more). Hydrogen gas is extremely
ammable and explosive. To prevent the possibility of injury
underthese conditions, we recommend the hotwaterfaucet,
locatedfarthestaway, be opened for severalminutes before
anyelectricalapplianceswhichareconnectedtothehotwater
systemareused(suchasadishwasherorwashingmachine).If
hydrogengasispresent,therewillprobablybeanunusualsound
similartoairescapingthroughthepipeasthehotwaterfaucet
isopened.Theremustbenosmokingoropenamenearthe
faucetatthetimeitisopen.
HIGH WATER TEMPERATURE SHUT OFF SYSTEM
Thiswaterheaterisequipped withan automaticgasShut-off
system.Thissystemworkswhenhighwatertemperaturesare
present.ThehightemperatureShut-of fisbuiltintothegascontrol
valve.Itautomaticallyresetswhenthetemperatureatthermostat
leveldropsbelow120degreesFahrenheit.