AquaStar 80 VP User manual

WARNING: If the information in this manual is not
followed exactly, a fire or explosion may result
causing property damage, personal injury or death.
FOR YOUR SAFETY
Do not store or use gasoline or other flammable,
combustible or corrosive vapors and liquids in
the vicinty of this or any other appliance.
WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electrical switch; do not use
any phone in your building.
• Immediately call your gas supplier from a
neighbor's phone. Follow the gas supplier's
instructions.
• If you cannot reach your gas supplier, call the
fire department.
- Installation and service must be performed
by a qualified installer, service agency or
the gas supplier.
Upon completion of the installation, these instructions should be handed to the user of the appliance for
future reference. *REPLACEMENTMANUALMUSTBEPURCHASED
FEATURING: VariablePower -Modulating GasValve -Thermostatic Controlwith TemperatureDialSelector
INSTALLATION AND OPERATING INSTRUCTIONS
FOR AUTOMATIC INSTANTANEOUS TYPE WATER HEATERS
FOR USE WITH NATURAL AND LIQUEFIED PETROLEUM GAS
MODEL 80 VP AND MODEL 80VPS
Suitable for water (potable) heating and space heating

2
TABLE OF CONTENTS
Specifications ..............................................................................Page 3
Rules for Safe Operation.............................................................Page 4-5
General Overview of Aquastar ....................................................Page 6
Locating the Heater for Safe Proper Combustion........................Page 7
Installation ...................................................................................Page 8
Connecting Gas and Water Lines & Pressure Relief Valve .........Page 9-10
Vent Pipe Connection..................................................................Page 10
Safety Before Lighting.................................................................Page 11
Lighting Instructions ....................................................................Page 11
Setting Water Temperature..........................................................Page 12
Maintenance & Service ...............................................................Page 12-14
Trouble Shooting .........................................................................Page 14-18
Cleaning Pilot Assembly..............................................................Page 19
Calibration and Thermostat Test..................................................Page 20-21
Description of Operation and Parts Layout Diagrams .................Page 22-26
Gas Line Size, Vent Size & Height Guide Lines..........................Page 27
This well engineered, tankless gas water
heater has all the features a water heater
should have:
The instantaneous principle of heating water is
verysimple. Coldwater entersthe heaterwhen
ahotwater faucet isopened. Thisflow of water
causes the gas valve to open. Gas flows to the
burnersandisignitedbythepilotflame. Theheat
exchanger then absorbs the heat generated by
theburners andtransfersittothe coldwater asit
travelsthroughtheheatexchanger. Whenthehot
water is turned off, the gas valve automatically
closes and the burners shut off. Your hot water
faucet is an ignition key for hot water. You now
havecompletecontroloveryourhotwaterenergy
use. [Seepages22-26 fordetailedDescription
ofOperationand PartsLayout Diagrams].
FEATURES
• Automaticthermostatic controlfor steady
hotwater temperature. Burneroutput is
proportionalto waterflow for maximum
energyefficiency.
• Automaticthermostatic controlfor steady
hotwater temperature.
• Safetythermocoupleatpilot andburner.
• AutomaticEnergy Cut-Offmechanism.
• Built-ingasshut-offvalve.
• Stainlesssteelburnerswithstabilizedblue
flame.
• Built-in corrosion resistant draft inducer.
• Long working life insured by heavy-duty
high quality materials.
• Compact space saver: mounts on wall
with four screws.
• Easy installation.
• 2.2 gpm (removable) flow restrictor to
ensurewater flowwill neverexceedheater
capacity.

3
AquaStar 80 VP and 80 VP "S" Specifications:
Gasinput..................................max: 77,500Btu
min: 25,000 Btu
WaterConnection........................1/2"sweatfitting
HxWxD..........................................27"x12"x9"
Vent.......................................................................4"
GasConnection...........................3/4"NPTthread
Min.WaterPressure....................................15Psi
Max.WaterPressure................................150Psi
ShippingWeight..............................................33lb
NetWeight......................................................27lb
GPMat90ºFrise...........................................1.32*
GPMat45ºFrise...........................................2.64*
Min.WaterFlow....................................3/4gal/min
LPGASPressureinlet...............min.:10"W.C.***
max.: 14"W.C.**
LPGASManifold pressure....................8.9"W.C.
NaturalGasPressureinlet..........min.:4.7"W.C.***
max.: 14"W.C.**
NaturalGasManifold Pressure...............3.2"W.C.
* Figured on a 55ºF cold inlet temperature
** Inletgas pressuremust notexceed thisvalue
***Forpurposes ofinput adjustment
SETTING THE INLET GAS PRESSURE FOR HIGH ALTITUDES
The pressure regulator provided with the heater is set to deliver the proper gas pressure (as
indicatedon therating plateand inthe manual)foraltitudeupto2500feet(758meters)abovesea
level. Onappliances beinginstalledabove2500ft/758melevation,the inletgas pressureshould
bereset atinstallation tothe valueshown belowforthealtitudeoftheinstallation.
NOTE: The gas pressures specified below refer to pressures taken at the test pressure
nipple on the manual gas valve as shown in fig.3 page 9. These readings should be taken
while the heater is operating at full output --i.e. maximum water flow with the temperature
setting on #8.
MAXIMUMINLET GASFLOW PRESSURESETTING
ALTITUDE NATURALGAS LIQUIDPROPANE
inches W.C. inches W.C.
0' - 2,500 FT / 758 M 3.90" 9.75"
2,500 ft - 4,000ft / 758m - 1212m 3.00" 7.35"

4
CAUTION: RULES FOR SAFE OPERATION
If you are using the AquaStar for combined space heating and potable water heating ( see
schematic diagram below), all piping and other components connected to the system must
be suitable for potable water, (b) toxic chemicals such as those commonly used for boiler
treatment to prevent corrosion and freezing must not be introduced into the system, and
(c) if the space heating requires water temperatures higher than those required for do-
mestic, potable water, a mixing valve or other similar device must be provided to reduce
scald hazard potential. DO NOT CONVERT AN EXISTING, CLOSED HOT WATER HEATING
SYSTEM TO A COMBINATION SPACE AND POTABLE WATER HEATING SYSTEM USING
THE AQUASTAR OR ANY OTHER HEAT SOURCE.
Fig. 1 Schematic Diagram of Combination Potable Water and Space Heating System
RadiantFloor,
LowTemperature
Fan Coil Units,
BaseboardHeaters,
IndirectWaterHeater,
Snow Melt, or
Root-zoneGrid
Room
Thermostat
Pump(Grundfos
UP26-99BF,
Taco0011B
orequivalent)
DipTube
Secondary
Pump
Hot
Water
Out
BoilerDrain
Pressure
Relief
Valve
Cold
Water
In Full Port
BallValve
Full Port
BallValve
Aquastat
Sensor

5
RULES FOR SAFE OPERATION
1. Youshouldfollowtheseinstructionswhenyou
installyourheater.
Inthe UnitedStates: The installationmust con-
formwithlocalcodesor,inthe absenceof local
codes,theNationalFuelGasCodeANSIZ223.1/
NFPA 54.
InCanada: Theinstallation shouldconformwith
CGA B149.(1,2) INSTALLATION CODES and/
orlocalinstallationcodes.
2.Carefullyplanwhereyouinstalltheheater. Cor-
rect combustion air supply and flue pipe instal-
lation are very important. If a gas appliance is
notinstalled correctly, fatalaccidents canresult
from lack of air, carbon monoxide poisoning or
6. Keep water heater area clear and free from
combustibles and flammable liquids. Do not lo-
cate the heater over any material which might
burn,such ascarpet.
7.Correctgaspressureiscriticalfortheoptimum
operation of this heater (see specifications on
page 3). Gas piping must be sized to provide
therequiredpressure atthe maximum outputof
the heater. Check with your local gas supplier,
andseegaslinesize requirementson page 27.
8.Asaprecaution,shutoffyourheaterifyouplan
tobeawayforseveral days.
9. Shouldoverheatingoccurandthe gassupply
fail to shut off, turn off the manual gas control
valve to the appliance.
10.Seeinstructionsonsettingthewatertempera-
ture,page12.
11. Donot usethisapplianceifanyparthasbeen
underwater. Immediately callaqualifiedservice
techniciantoinspecttheapplianceandtoreplace
any part of the control system and any gas con-
trolwhich hasbeenunderwater.
fire.
3. The place where you install the heater must
haveenoughventilation. TheNationalFireCodes
do not allow water heater installation in bath-
rooms, bedrooms or any occupied rooms nor-
mallykept closed. SeethesectiononPages 7-8
onLocating theHeater.
4.Youmustventyourheater. SeesectiononVent
Pipe Connection, Page 10, paragraph 6 and
Venting Guide on page 27.
5. The appliance and its individual shutoff valve
must be disconnected from the gas supply pip-
ing system during any pressure testing of that
system at pressures in excess of 1/2 psig
(3.5kPa).
The appliance must be isolated from the gas
supply piping system by closing its individual
manualshutoffvalveduringanypressuretesting
ofthegassupplypipingsystemattestpressures
equal to or less than 1/2 psig (3.5kPa). The
appliance and its gas connection must be leak
testedbeforeplacing theappliance in operation

6
I. hot water outlet
J. thermostat adjustment screw
K. gas inlet
L. manual gas valve
M. cold water inlet screen
P. pilot starting button
R. water valve venturi piston
S. pilot filter
X
W
V
T
S
R
PMZK
H
J
G
F
D
E
C
B
A
IY
Fig. 2 Parts of AquaStar 80
L
T. pilot
V. overheat shut off sensor
W. draft hood
X. rating plate-serial #
& gas type, etc.
Y. incandescent particles tray
Z. gas pressure testing nipple
or gas valve
A. hanging frame and back
support
B. thermostatic sensor
C. heat exchanger
D. thermocouple
E. burners
F. burner manifold
G. gas pressure testing nipple
H. temperature selector knob

7
LOCATING YOUR HEATER FOR SAFE PROPER COMBUSTION
Carefully select the location of your new heater. For your safety and for proper heater operation,
you must provide an abundant supply of combustion air and install a proper vent. The heater
may still operate even when improperly installed. However, an improper installation will be less
efficient and may damage the heater. Improper installation can even result in human sickness or
death due to oxygen deprivation and carbon monoxide poisoning. Follow the guidelines below:
Appliances located in confined spaces:
Theconfinedspaceshallbe provided
withtwo permanentopenings, onecom-
mencingwithin12inchesof thetop and
onecommencing within12inchesofthe
bottomof theenclosure. Eachopening
shallhaveaminimumfree areaof one
squareinch per:
-1,000Btu/hrif allair is takenfrom inside
thebuilding.
-2,000Btu/hrif allair istakenfrom the
outsidebyhorizontalducts.
-4,000Btu/hrif allair istakenfrom the
outsidebydirect openingsor vertical
ducts.
Louvers, grills and screens have a block-
ing effect. If the effective free area is not
known,assume20% to25% for woodlou-
vers and 60% to 75% for metal louvers.
Refer to the National Fuel Gas Code for
complete information. In buildings of tight
construction, all air should be taken from
outside.
5. Place your heater as close to a vent or chim-
ney as possible. Your hot water lines should be
kept short to save energy. It is always best to
havehot waterlinesinsulated.
6. Havingafloordrainor sinknearby ishandy in
caseyou needto drainwater fromyour heater.
7. Place the heater in a location where water
leaks will do NO DAMAGE to adjacent areas or
lower floors. CONTROLLED ENERGY CORP
IS NOT RESPONSIBLE FOR WATER DAM-
AGE.
1.Youmustnotinstallthisapplianceinbathrooms,
bedrooms, unvented closets or any occupied
roomsnormally keptclosed.
2. Simultaneousoperationofappliancessuchas
exhaustfans,ventilationsystems,clothesdryers,
fireplacesorwood stovesmay createavacuum
effectinyour home. Thiscancause dangerous
combustion by-products to spill back into your
homeratherthan ventingto the outsidethrough
theflue.
3. A simple test for proper ventilation is to
inroducesmoke (asfromacandle)nearthelou-
vers on the front of the heater. Have all appli-
ances mentioned in the above paragraph oper-
ating at the same time. Have all doors and win-
dows to the outside shut. If the heater does not
suckthe smokeinto thelouvers whilethe heater
isoperating,youneedto supplyadditional com-
bustionair totheheaterand/orimprovethevent
system.
4. Observethe followinginstructionsconcerning
additionalcombustionair.
Applianceslocatedin unconfinedspaces:
a)Anunconfined spaceis oneinwhich
thevolumeisgreaterthan 50cubic feet
per1000Btu per hourofthe combined
ratingofallappliancesinstalled inthe
space. That would be 6250 cubic feet
fortheAquaStar125alone.
b)In unconfinedspaces inbuildings of
conventionalframe,masonry,or metal
construction,infiltration isnormallyad-
equatetoprovideairforcombustion,ven-
tilation,and dilutionoffluegasses.

8
heater. Usethe adhesivetape whichis included
in the package to stick the pattern to the wall.
Keepinmind that theheaterneeds to havecer-
tain minimum clearances (See paragraph 7 on
thispage),andthattheheatermustbelevel. Drill
fourholes intothewallatthe studs(16 incheson
center) as indicated on the template. Use a 1/8
inchdrillif screwsareto godirectlyinto woodor
1/4inchif plastic anchorsareto be used.
WARNING: Be sure to remove the paper
template before hanging the heater on the
wall.
After the paper template is removed, insert the
mountingscrewsintothetwoupperholes. Leave
1/2inch betweenthewallandthe screwhead, in
order to have enough space for your unit to slip
over. The bottom screws will secure the Water
andGasConnectingStripAssembly tothe wall.
Nextremove thefrontpanel. To dothis,remove
the temperature selector knob (H) and the pilot
startingbutton bypulling themout. Unscrew the
screwsundereachfrontcorner. Liftthepanelup
and pull out. At this point, you can either screw
thetwolarge screwstofastentheWaterandGas
ConnectingStripAssembly tothe wallusingthe
pre-drilledholesandconnectyour pipesdirectly
tothewater heater, oryoucanremovetheheater
fromtheWaterandGasConnectingStripAssem-
bly in order to connect the piping, and then re-
connecttheheaterlater. Ifyoudecidetoconnect
thepipes directly,skipthenextsectionand goto
#3,"ConnectingtheGasLine."
2. To Disconnect Heater From the Water and
Gas Connecting Strip Assembly (Optional)
Refertofigure3(followingpage). Unscreweach
brassunion nutat thethree pointsmarked infig-
ure 3. Be careful not to lose the washers. Re-
moveyourheater fromthe Waterand GasCon-
nectingStrip. Nowyoucanmakeyourwaterand
gas connections as explained in the following
sections. Whenallconnectionshavebeenmade,
re-hang the heater on the upper screws and re-
connectthebrassunionnuts makingcertainthat
thewashers areproperlyinplace.
8. Foralcove installation,maintainthefollowing
minimumclearancesfromallconstructionforser-
vicingandproper operations:
Alcove Closet
A.Top 6 inches 12 inches
B. Front OPEN 6 inches
C. Back 0 inches 0 inches
D. Sides 1 inch 1 inch
(Left side 6" for service)
E. Floor 6 inches* 12 inches*
F. Flue 6 inches 6 inches
(single wall only)
*Do not install over floor covering which is combustible,
such as carpet.
Minimum clearance to combustible materials
shouldnotbelessthan6"forsinglewallfluepipe.
Note that this can be reduced if combustible
materials are protected as per table VI of the
National Fuel Gas Code or if Type B gas vent is
used. (Follow the minimum clearances for the
venttype. Werecommendthe useofTypeBgas
vent.
9. WARNING: THIS WATER HEATER DOES
NOT STORE ANY HOT WATER. DO NOT IN-
STALL IN AN AREA WHERE IT COULD
FREEZE. This heater is neither designed for
nor approved for outside installation.
10. The heater must be level before you begin
thepiping.
INSTALLATION
Before installing the unit, be certain your heater
isforyour type ofgas- Propane orNaturalGas.
Identification labels for type of gas are found on
the shipping box, on the right side panel and on
the rating plate which is located in upper part of
draft hood seen by removing front panel (See
"X" Fig. 2, page 6). Also, each gas orifice is
stamped with a number (75 for LPG and 115 for
NaturalGas).
1. Hanging the heater on the wall
Placethepaperpatternortemplate(suppliedwith
heater) on the wall where you plan to hang your

9
3. Connecting the Gas Line
In the United States: The installation must con-
form with local codes or, in the absence of local
codes,theNational FuelGasCode ANSIZ223.
1/NFPA 54.
InCanada: The installationshould conformwith
CGA B149 INSTALLATION CODES and/or lo-
calinstallationcodes.
IMPORTANTAnappliancegaspressure regula-
torhas beensuppliedwiththisunit. Thisregula-
tormustbe installedon thegasline within6 feet
of the heater. National Fuel Gas Code requires
that a sediment trap be installed on gas appli-
ances not so equipped. The 3/4" NPT gas inlet
elbowfitting suppliedwiththeheaterconnects to
themanual gasshutoffvalvewithawashergas-
ket. Nopipe dopeorthreadtapeshould beused
atthis joint. The3/4"NPTsideof thefittinghasa
hexshouldertohelpyouavoidtwistingtheelbow
and requires pipe dope or thread tape to make
its seal. The 3/4" size is the minimum for use
withNatural Gasand mustnot bereduced. Pro-
pane gas line size requirements are less than
thoseforNatural Gas. Providedthepropanegas
line is less than 20 feet and serves only the
AquaStar, it can be reduced to 5/8". When
threading the gas pressure regulator to the gas
piping,theindicatorarrowon theregulator must
be pointed in the direction of gas flow.
NOTE: The regulator supplied with the
heater is an appliance level regulator de-
signed for low inlet pressure (less than 1/2
LB or 15"W.C.). DO NOT connect to an un-
regulated or high pressure propane line.
Whenyour connectionsaremade,checkfor gas
leaksatalljoints(notjustonesyoumade). Apply
somesoapywatertoallgasfittingsandgasvalve.
Soap bubbles are a sign of a leak.
NOTE: Do not apply soap solution to pilot filter
screen or pilot orifice area. If you have a leak,
shutoffthe gas. Afterverifyingthatrequiredgas-
kets are in place, tighten appropriate fittings to
stopleak. Turnthegasonand checkagain with
asoapysolution. Never testfor gas leaksusing
amatchorflame.
4. Connecting the water lines
Althoughwater pipingthroughoutyourstructure
maybeotherthancopper, copperpiping should
be used for at least three feet before and after
theheater(follow localcodesif morestringent).
Keep water inlet pipe to at least 1/2 inch diam-
eter to allow the full flow capacity. Remember
that piping and water pressure must allow suffi-
cientflowtoactivatetheheaterwhendrawinghot
water from the top floor. If the hot and cold con-
nections are reversed, the heater will not func-
tion.
Fig. 3 To Disconnect Heater From Wall Hanging Strip

10
Sweatyour coldwater pipeto theAquaStar inlet
elbowfitting. NOTE: The inlet filterscreenand
waterflow restrictorcan be damagedby heat
if the cold water inlet elbow is attached to
the AquaStar when it is sweated to the cold
water inlet pipe. The inlet and outlet elbow fit-
tingsseal bymeans ofaunionconnectionwitha
washer type gasket at the joint. Although these
fittingshave1/2"threads,NPTfittingsshouldnot
besubstitutedfortheseelbowsandnopipedope
orthread tapeis tobe usedat thejoints. Be cer-
tainthere areno looseparticles ordirt inthe pip-
ing. Blow out or flush out the lines before con-
nectingto theAquaStar.
5. Connecting the pressure relief valve
Atemperature andpressure reliefvalve mustbe
installedonthe hotwaterline,closetotheheater.
Novalve istobeplacedbetweenthereliefvalve
andtheheater. Installation shallbemadeinsuch
a manner that the discharge from the tempera-
ture and pressure relief valve will be conducted
to a suitable place for disposal when relief oc-
curs. No reducing coupling or other restriction
may be installed in the discharge line. The dis-
charge line must be installed such that it allows
completedrainage ofboththevalveand theline.
The location of the relief valve must be readily
accessible for servicing or replacement. To ac-
commodatethepressure reliefvalve,a suitable
fitting connected to an extension of a "T" fitting
can be sweated to the line. Make the T-fitting
extensionlongenoughtoensurethatthetempera-
tureprobe doesnot interferewith thewater flow.
Therelief pressureof thevalve mustnot exceed
150psig. Therelieftemperatureofthevalvemust
not exceed 210ºF and the discharge capacity
mustbeat least125,000 Btuperhour.
6. Vent pipe connection. WARNING: Do not
reduce the vent pipe size.
Thisappliance mustbeventedtothe outsidefol-
lowingall localordinances andspecificationsfor
installinga gasapplianceventorchimney. The
gassestotheoutdoorsunder alloperating con-
ventingsystem mustbe constructedso asto
developapositiveflowadequate toremove flue
ditions.
Theappliance mustbelocatedasclose asprac-
ticabletoa chimneyor vent. The ventpipe sec-
tionsmust befastenedwithsheetmetalscrews.
Keep in mind the minimum clearance from the
top of your heater. Remember also that single
wallventpipe connectorsrequire a6inch clear-
ancefromcombustibles. NationalFuelGasCode
specifies double wall - Type "B" - vent pipe be
used in cold climates and for gas vents running
throughattics. Weconsiderdoublewallventpipe
preferable in all circumstances. The vent con-
nectorshould haveas muchvertical riseas pos-
sible (minimum 12") before any horizontal run.
Any vent section greater than 45 degrees from
verticalis consideredhorizontal. Horizontalsec-
tions of vent connectors must slope upwards at
least1/4inchforeveryfootofitshorizontallength.
Keep the horizontal section short and avoid too
manyelbows.
Note: AlthoughtheAquaStarhasthesamevent-
ing requirements as other Category I gas appli-
ances,certain featuresandspecificusecharac-
teristics make it more important to have a vent-
ingsystemwhich exceedsminimum standards.
AquaStar thermostats modulate burner output.
Therefore, when operating at less than full out-
put, the heater does not have its full heating ca-
pacity to warm the flue pipes to create a natural
draft. Most gas appliances have longer duty
cyclesthan aretypical ofinstantaneousheaters.
For these it is considered sufficient if the appli-
ance can overcome a downdraft within the first
fiveminutesofoperation. Aninstantaneous "on
demand" heater like the AquaStar may have
frequent operating cycles of less than a minute.
If venting and air supply are inadequate to pro-
vide a positive draft as soon as the heater turns
on,theheatermaynot remainonlongenoughto
establish a positive draft. See venting guide on
page 27.

11
is lighted. Keep the center knob pressed
all the way in for at least 10 seconds after
pilot is lighted. Release push knob and
turn it clockwise to
If pilot goes out, wait 5 minutes before
relighting.
FOR YOUR SAFETY READ BEFORE LIGHTING
WARNING: If you do not follow these instructions exactly, a fire or explosion
may result causing property damage, personal injury or loss of life.
A. Thisappliancehas apilot whichmustbe
lightedby hand. Whenlighting thepilot,
followtheseinstructionsexactly.
B. BEFORELIGHTING smellallaroundthe
appliance area for gas. Be sure to smell
nextthefloor becausesome gas is
heavierthanairandwillsettleonthefloor.
WHATTODO IFYOUSMELL GAS
• Donottry tolight any appliance.
• Donottouch anyelectrical switch;do
notuse anyphone inyourbuilding.
• Immediatelycallyourgassupplier from
a neighbor's phone. Follow the gas
suppliers's instructions.
• Ifyou cannotreach yourgas supplier,
call the fire department.
C. Useonlyyourhand topushin orturnthe
gascontrol knob. Neveruse tools. Ifthe
knobwillnotpushinorturnbyhand,don't
tryto repairit, calla qualifiedservice tech
nician. Attemptedforcefulrepairmayre
sultinafireor explosion.
D. Donotuse thisappliance if anypart has
beenunder water. Immediatelycalla
qualifiedservice technicianto inspectthe
applianceandto replaceany partofthe
controlsystem andanygascontrolwhich
hasbeen underwater.
LIGHTING INSTRUCTIONS
1. STOP! Read the safety information
above.
2. Pushingascontrolhandleslightlyand turn
clockwise to "RED DOT" position.
3. Wait five (5) minutes to clear out any gas.
If you smell gas, STOP! Follow "B" in the
safetyinformationabove. Ifyoudon'tsmell
gas, go to next step.
4. Turn handle on gas control counterclock-
wise to "RED FLAME" position.
In the United States: The installation must con-
form with local codes or, in the absence of local
codes,theNational FuelGasCode ANSIZ223.
1/NFPA 54. In Canada: The installation should
conform with CGA B149 INSTALLATION
CODESand/orlocal installationcodes.
If knob does not pop out when released, stop
and immediately call your service technician or
gassupplier. If thepilot willnot staylightedafter
several tries, turn the gas control handle off to
"RED DOT" position and call your service tech-
nicianorgas supplier.
TO TURN OFF GAS TO APPLIANCE
Turngascontrolshutoffhandletothe"REDDOT"
symbol. Donotforce.
5. Check that manual gas valve handle is on
"RED FLAME" position. Push in center
PILOT LIGHTING knob on the front of the
AquaStar and twist counterclockwise
to .Push knob all the way in and hold it
in. While holding knob in, light the pilot
with a match through pilot viewing open
ing in front of the heater. Check that pilot

12
SETTING THE WATER TEMPERATURE
The AquaStar 80 water heater contains a flow
restrictor set at 3 1/4 gpm. Its purpose is to as-
sure that the hot water temperature will always
bewithin acomfortable rangeregardless ofhow
highone mayturnonthehot waterfaucetorhow
manyfaucets maybeturnedon. Your AquaStar
model80alsohasanautomaticthermostaticcon-
trolwith amanual temperaturesetting(Fig.2let-
ter H p. 6). For energy efficient operation, we
recommend operating this heater at the lowest
temperature which you require in your applica-
tion. Thiswillprovideamoreconsistenttempera-
tureovera widerrange offlow. Lower tempera-
turesettingshelppreventtemperaturefluctuations
thatmayoccurwhenotherwateroutletsareused
simultaneouslyoroverallwaterpressurechanges
orexcessivecoldwaterhastobeadded. Inhard
water areas, reducing the water temperature
greatly reduces the potential for mineral scale
build-upintheheatexchanger.
What is the best temperature setting?
Because AquaStar water heaters can deliver
endlesshotwaterattheexacttemperaturewhich
you have selected, there is no need to set it for
veryhotwaterandthenmixincold. Itjustdoesn't
make sense to overheat water then mix in a lot
of cold water to cool it off. Remember you can-
notrunout of hotwaterwith anAquaStar,soset
thedialforthe(exact)temperaturethatyouneed.
MAINTENANCE AND SERVICE
Approximatelyonce ayear,theAquaStarshould
bechecked,cleanedandservicedasnecessary.
The following operations must be performed by
aqualifiedservice person:
Vent System: Should be checked annually.
Clean and repair as needed.
Water Valve (Part #34343): Thewater valveon
this heater should be serviced periodically de-
pendingonhardness ofwaterand conditions of
useorwheneversignsofcorrosionappearatthe
gasand watervalvejoint. Servicingthewater
valveconsistsofreplacingthePushRodAssem-
bly(part#21107), theDiaphragm (part#32570),
andtheWaterValve SpringLoaded Piston(part
#34542).
Drainage: Drain the heater if there is any dan-
ger of freezing. Shut off the water supply, open
allhotwater faucets,and disconnect thelowest
AquaStarfittings andthe connectionsto thewa-
ter valve (Fig 2, (R), page 6). Loosen the 2 re-
tainingscrewsattheconnection tothegasvalve
and rotate the water valve 360oto empty all the
water. Thepressure-temperaturereliefvalveop-
eration should be checked. Perform a manual
operation of this valve at least once a year en-
suring that a drain is nearby to receive any dis-
charge (see section 5, page 10). Take precau-
tionstoavoid contactwith hot watercoming out
ofdischarge openingand toprevent waterdam-
age. Do not plug the relief valve. If the relief
Note: 105ºF is the maximum recommended
for a hot bath. The temperature you select will
holdoverarangeofwaterflowrates. (Seechart,
Fig. 6, page 18). You may further vary the tem-
perature by signficantly changing the flow rate,
particularly at the highest temperature settings.
model "S" version heater. The model "S"
is aspecifically modifiedAquaStarwhichwill
notoverheat ifinletwaterisalready hot.
Position "5" on the temperature dial is the pre-
ferred starting point for setting the temperature
control. This setting provides approximately
130ºFdependingontheflow rate.
Positions "2" and "3" provide approximately
105ºF,adequateforashowerdepending onflow
rate.
Positions "4" through "6" are intermediate set-
tingsbetween warmandveryhot.
Position"8" allowsforthehottesttemperatureof
about150ºFuptoabout 1.8gallons perminute.
WARNING: 150ºF can cause third degree
burns.

13
valve discharges by itself, a problem exists and
service is required. This could be due to a de-
fectiverelief valveor tooverheating.
Pilot Flame: The pilot flame should burn with
a clean sharp blue flame and should resemble
Fig.4 below. If the flame is yellow, or if the
central button Fig. 2 (P) has to remain de-
pressed for a long time in order to keep the pilot
lighted, the pilot may need to be cleaned or the
orifice replaced.
Fig. 4 Characteristic Pilot Flame
To clean the pilot:Turn off the gas at the unit
Fig. 2 (L). Remove the front panel (unscrew
screws at bottom of corners of front panel, pull
outandlift paneloff). DisconnectthePilot Tube
Fig. 2 (S) at its base and blow gently through it
( see diagram of Pilot Assembly, page 19). Be
careful not to lose the pilot orifice and
washers. Remove and clean pilot filter by
peeling off the outer layer. Do not use any wire
or sharp object to clean orifices. Natural gas
orifices are large enough that you can usually
cleanthembyblowingthrough them. LPorifices
are too small to clean and should be replaced.
Do not enlarge the orifice.
Main Burner Flames: The main burner flames
shouldbe blue,with amore intenseblue conein
thecentercore. ComparewithFig 5inopposite
column. Yellowflames couldbeasignof wrong
size gas orifices or dirty burners. If some burn-
ers have yellow flames while others have good
flames, it is likely that dust, lint or spider webs
havepartiallycloggedtheburner venturi.
Washthestainlesssteelburnersif theyaredirty.
Burnerscanbe detachedfromthe heaterbyre-
moving the pilot tube and the thermocouple as-
sembly anddisconnecting theEnergy-Cut-Off.
(Do not lose the retaining clip) The burners
aresecuredtothemain frameby twoscrewson
eitherside. Donotremovethefivescrewsacross
the front of the burner assembly. Also examine
heatexchangerfinsfordirt. Brushandvacuumif
dirty. Burnt edges at the bottom of the heat ex-
changershroudareasign ofinadequateairsup-
ply,poorventingorsomeothercombustionprob-
lem. Thecauseofthissituationmustbecorrected:
contactyourinstaller,serviceagency orthe gas
supplier.
WARNING: Accumulation of dust and lint on
the heat exchanger fins will reduce air flow
and could cause corrosion of the copper
heatexchanger. Keep theapplianceareaclean
andfreefromcombustiblematerials,gasolineand
other flammable liquids and vapors. Do not ob-
struct the flow of combustion air and ventilation
air. If installednear adryer,makesurethedryer
is properly vented, and that the AquaStar vents
properlywhen thedryer isoperating.
Fig 5. Characteristic Burner Flame Pattern
-to thermocouple
toburners -

14
gaspressure. Excessive pressurewill lockitup.
Thisproblemusuallyhappensifthegaspressure
between the gas tank and the water heater has
not been reduced. See page 3 of your manual
for specified gas pressures.
Tounjamaregulator,removethenickelsizescrew
plugonthefront. Insideyouwillseeanotherlarge
screw. Draw alinedownthethreads tomarkthe
locationofthescrew. Removethescrewandpush
onthebottomoftheholewiththeerasersideofa
pencilor similarobject. This willrelease thedia-
phragm. Reinsert the screw and screw it down
totheendofthe markyou made.
3. Pilot orifice cloggged and/or air screen
dirty, or pilot filter is dirty.
Clean the pilot orifice and/or pilot filter screen.
Disconnectthepilottube(T)byunscrewingit. Be
careful not to misplace the small washers. The
diagram on page 19 shows how the parts of the
pilotassembly fittogether.
Naturalgasorificesarelargeenoughthatyoucan
usuallycleanthembyblowingthroughthem. The
LP orifice is so small that it is best to replace it.
Never try to enlarge the hole, or use a sharp
hard object for cleaning.
Thepilotgas filteris made froma layeredmate-
rial. If it becomes too dirty, a portion of the filter
canbe separatedandpeeledoff. Theclean por-
tion should be loosely reinserted into the pilot
burnerbrassfilterchamber. Becarefulwhenre-
installingthepilotburnertoaimtheburnersothat
thesmallerrighthandpilotflametouchesthether-
mocoupletip.
2. In-line AquaStar gas regulator jammed
(usually with LP gas)
Replaceorunjamtheregulator. Note: Theregu-
latorfurnishedwiththeheaterisdesignedforlow
PILOT WILL NOT LIGHT
1. No gas to the AquaStar
A. Gas cock on gas line may not be open.
B. AquaStar manual shut off valve at base of
heaterisnotopen. Turnhandletoredflamesym-
bol.
Letterreferences,e.g. "L"in this sectionrefer to
Fig. 2 on page 6.
Introduction:TheAquaStarburnersareignited
by a water flow valve. Numerous water related
problemscan causethis watervalve tomalfunc-
tionsuch as:
1. insufficient water flow volume to activate the
burnersat theirminimumflowrequirement
2.dirtinthewater flowvalvecausingthevalveto
malfunction
3.sediment buildupin faucetaeratorsorshower
heads
4.uneven pressuresbetweencoldandhot(with
singlelever faucets)
5.plumbing cross-overs
These water related problems can cause the
heatertodeliverlessthanitsfulloutput,ortoshut
downcompletely.
SPECIFIC PROBLEMS AND ANSWERS
Note: Problems are stated in upper case, bold
face. Mostcommoncausesfortheproblemsfol-
lowin orderof likelihoodofoccurence. Formost
ofthesuggestedsolutions,itwillbenecessaryto
take the front cover of the heater off. To do this,
pullthe knobsoffandremovethe screwsat front
bottom corners, then lift and pull the front panel
off. Itisalsoadvisabletoremovethebottomtray:
pullofftheplastichandleofthemanualgasvalve
andloosenthesidepanelbottomscrewsandthen
pullthetray down.
TROUBLE SHOOTING
Mineral Scale Buildup:AquaStars, when operated at high temperatures or in hard water areas,
may need periodic descaling. To check the inside of the heat exchanger for scaling, remove the
heat exchanger by first removing the thermostat sensing element (B), page 6. If you note mineral
buildup,flush witha descalingsolution. Consult yourdealer orcall CECfor instructions.

15
3. Poor circuit connections at the ECO
(Energy Cut-Off)
Oxidation or looseness of the ECO screw con-
nectionscanresultinmillivoltcurrentlossthrough
thethermocouple safetycircuit. Clean terminals
with very fine sand paper or an eraser and re-
tighten terminal screws. (See letter V in Fig 2,
page 6).
4. Faulty Energy Cut Off (ECO)- Part 34209
Ifcleaningandretighteningthescrewsonthether-
mocouple wires attached to the ECO did not fix
theproblem,testtheECO bydisconnecting a
wirefrom oneside ofit andreconnecting ittothe
other side so both wires are making good con-
tact. Relight the pilot. If the pilot flame now re-
mainson,replace theECO. Iftheflamestillgoes
out when the button is released, the ECO is not
defective. Gotothenextstep (#5below).
5.Poor thermocoupleconnection at theelec-
tromagnet (part #20883)
Note: The electromagnet is located directly be-
hindthe pilotpushbuttonassemblyat therearof
the gas control. Tighten the thermocouple con-
nection tothe electromagnet. Theconnectionis
a large brass collar and a nut at the back of the
gasvalvedirectly oppositethepilot pushbutton
assembly. The thermocouple end is a 12 mm
(15/32") nut which screws into a 16 mm (5/8")
hexfitting onabrasscollar. Thislargebrasscol-
lar must be snug before you tighten the smaller
nut in order to avoid twisting and damaging the
thincopperthermocoupletube. Tightenthether-
mocouplenut snugbutnottootight.
6. Faulty thermocouple or electromagnet
(parts #20887 and 20883).
Unlessthese partsareat least8-10years old,
it is very unlikely that they are faulty. Before
testing, reconfirm that #2 is absolutely cor-
rect, and all connections are clean and tight.
Totestthethermocouple,disconnectthethermo-
couple from the electromagnet and disconnect
the thermocouple wires from the ECO.
a propane tank has been allowed to empty, or
the heater has been shut down for a long time.
Bleedall theairtrappedinthe gasline. Because
of the very small pilot orifice (especially on LP
gas models), bleeding out all the air could take
several minutes. Hold the pilot push button
pushed in until all the air has escaped, and the
gashasarrived.
PILOT LIGHTS BUT FLAME GOES OUT
WHEN BUTTON IS RELEASED
1. Pilot push button was not pushed in far
enough or was not held in long enough
Pushpilot buttonin, turnit tothe left,thenpushit
in all the way. Hold it pushed in for at least 20
seconds to give time for the pilot flame to prop-
erly heat the tip of the thermocouple before re-
leasing it. See Lighting Instructions, Page 11.
2.Pilot flame improperlyaimedor istooweak
soit isnotproperly heating thetipof thether-
mocouple
Thepilot flamehas twoflames,oneaimedatthe
thermocouple and the other aimed at an angle
towards the burners ( see pilot flame diagram,
Fig. 4, page 13). It is extremely important that
theflame directedonthethermocoupleheadbe
aimedrightatit,andthatthepilotflamebeasharp
blueflame. If thepilot assemblyhas beentaken
apartforcleaning, thepilot flame mayno longer
beproperlyaimed.
4. Pilot orifice may not be correct for your
type of gas.
Pilot orifice is stamped: #18 for LP and #35 for
NG.
5. Air in the Gas Line
Note: Normallythis isaproblemonlyatthetime
ofinstallationif thepipes havebeenworked on,

16
7. Water valve parts may be dirty or compo-
nents damaged.
Note: If #4 is OK, skip this.
Watervalveandcomponentpartsmustbetotally
freeofdirt. In hard waterareas,mineral depos-
itscaneventually(3-5years)corrodewatervalve
parts to a point where they will need replacing.
Note: there is a small bleed hole under the gas
valve at the seam where it is connected to the
water valve assembly. Any sign of corrosion at
this location is a sign that the water valve as-
sembly components need to be replaced im-
mediately. Water valve for Model 125 (34343)
consists of parts #21107, 32570 and 34542.
Contactservicepersontoservicethewatervalve.
a bad washer at a single lever faucet, incorrect
piping or an automatic mixing valve in the line
which permits hot and cold water to mix in the
plumbing. Thecrossoverwillcreateabackpres-
sureinthesystempreventing thepressure drop
in the AquaStar - i.e. cold water is entering the
watervalvefrom bothsides and theburners will
notcome on. To confirmthereisnocrossoverin
theplumbing,shutoffthecoldwatersupplytothe
AquaStar. Open your hot water taps. There
shouldnot beanywaterflowing. Ifthere iswater
flowing,thereisacrossoverintheplumbing. This
is a plumbing problem, not an AquaStar prob-
lem. Pleasecontact yourplumber.
Attach a multimeter lead on the thermocouple
coppertubingbelowthehead,andattachtheother
meter lead on the ends of both the wires. Light
the pilot and take a reading on the meter. If it
readslessthan24mv,replacethethermocouple.
Ifthe readingis 24mv orover, thethermocouple
is good.
Totesttheelectromagnet,reconnectthethermo-
couple and take another reading. The reading
should drop to about 14 mv. If it does not, re-
placethe electromagnet.
PILOT LIGHTS BUT GOES OUT DURING OR
IMMEDIATELY AFTER HOT WATER USE
1. Thermostat calibration is incorrect
The thermostat is not maintaining the proper
burneroutputforthewater flowand theheat ex-
changeris overheating. Whenthishappens,the
ECOsafety tripsand shutsoffthemaingassup-
ply. Aftertheheatexchangercools,the ECOre-
sets and the pilot can be relighted. In order to
check the calibration, see page 20. If the ther-
mostatcannotbecalibratedproperly,it isdefec-
tive and must be replaced (see page 21).
MAIN BURNERS DO NOT IGNITE WHEN
HOT WATER IS TURNED ON
1. Pilot is not on.
Lightthepilot. Seelightinginstructions.
2. Pilot lighting push button not turned to
proper position
Whenthe pilotflameison, besure thatthepush
button is released fully and is turned to the right
onthe burnerposition (3flames symbol).
3. Cold incoming water connection made to
wrong side of heater
Make sure cold water inlet connection is on the
rightsideofheaterwhenyouarefacingtheheater.
4. Water flow rate at hot water tap is too low.
Note: The AquaStar model 80 requires 3/4 gal-
lonsperminuteflowtoactivatetheburners. This
isaflow whichfills a quartjar in20seconds.
5. Cold water inlet screen on heater is dirty.
Removethisscreen (Min Figure 2,page 6)and
cleanit.
6. Crossover in household plumbing
TheAquaStarburner activateswhenthereissuf-
ficient water pressure drop in the AquaStar wa-
ter valve assembly when a hot water faucet is
opened. If there is a plumbing crossover, the
necessarypressuredrop intheAquaStarwill not
occur. A plumbing crossover can be caused by

17
2. Water flow through the heater is higher
than the capacity of the AquaStar to heat it
IftheAquaStar flowrestrictorhasbeenremoved,
theflowthroughtheheater mightbe higherthan
itscapacity toheatit. Reducetheflow toarange
withinwhichtheheatercanmaintaintemperature.
SeeflowchartonPage18. AquaStarwaterheat-
ers have a (removable) flow restrictor to assure
that the maximum volume flowing through the
heaterremains inthe rangethat theheater can
2. Gas pressure too low
Very low gas pressure may be caused by low
delivered gas pressure, by a jammed gas regu-
lator or by undersized gas lines. If the gas lines
are undersized, there may still be the specified
staticgas linepressure. However, whenthe wa-
ter valve opens, the pressure will drop sharply,
causing the pilot flame to go out. Have a gas
servicepersonconfirmthegas pressureboth
statically and at maximum Btu input. Specifica-
tionsforyour heaterare onpage3.
3. Burners are not shutting down immedi-
ately when hot water is turned off
If burners don't shut off immediately when hot
water is turned off, the heater will overheat and
the ECO will shut off the gas. Replace all three
partsin thewatervalveassembly(parts #21107,
34542, 32570. (See Letter R, Fig 2, page 6).
WATER IS TOO HOT
1. Temperature setting is too high
Unlikestoragetankheaterswhichneedtobeset
at a higher temperature than is needed in order
to stretch the volume of hot water by mixing in
coldwater, anAquaStarcan beset forthe exact
temperatureneeded andgive endlesshot water
without need for mixing in cold water. We rec-
ommendsettingthetemperatureselector dialon
#4 or #5. For more information, see section on
SettingWaterTemperature,Page 12.
2. Inlet water temperature is too high (as with
preheated water)
Note: Only the Model "S" AquaStar should be
usedifthe inletwater ispreheated.
3. Thermostat is not functioning properly
(See#1under PILOTLIGHT GOESOUTDUR-
INGOR AFTERHOTWATER USE)
WATER IS NOT HOT ENOUGH
1. Temperature dial is set too low
Changethe setting.
heattoa suitabletemperature,regardlessofhow
many faucets are being used. This is to ensure
thatthe flowisneverhigherthan whattheheater
canheattoasuitabletemperature. TheAquaStar
model 80 flow restrictor is set for a maximum of
2.2 gallons per minute. Note: In private well in-
stallations,thehighandlowcyclingcontrolofyour
water pump may be set too low or the pressure
tankmaybewaterlogged.
3.BTU inputistoo lowdueto insufficientgas
pressure
It is extremely important for a tankless water
heater to have the right size gas line to ob-
tain the correct gas pressure.
See specifications for correct gas pressures on
page 3. Unlike storage tank water heaters, the
burnersofa tanklesswater heater mustbe very
powerfultoheatwaterinstantaneouslysincethey
dothisonlyatthetimehotwaterisactuallybeing
used. It is imperative that the gas pressure re-
quirementbemet exactly. Insufficientgaspres-
sure will directly affect the water temperature.
Staticgaspressure inthe line canbe measured
at the pressure test nipple located on the
AquaStarmanualshut-off valve(LetterL, Fig2,
Page6). Manifold pressuremaybetestedat the
manifoldpresure testnipple(LetterG).
4.BTU inputistoo lowdueto insufficientgas
supply
Make sure your main gas line is fully opened. If
usingLP gas,minimum sizeof thepropane tank
shouldbe 100pounds forbest results.

18
5. Cold water is mixing with the hot water
between the AquaStar and the outlet
ComparewatertemperatureatoutletofAquaStar
andat thetap. Checkforautomaticmixing valve
plumbing crossover (see #6 - MAIN BURNERS
DONOTIGNITEWHENHOTWATER ISON).
6. Parts in water flow valve (#34343) are
corroded
The gas valve will not open fully if water valve
parts are corroded. Replace all three parts in
watervalve(#32570, #21107, #34542).
HOT WATER TEMPERATURE FLUCTUATES
1. Temperature setting is too high
Settingthetemperaturetoohighwillmakeitnec-
essarytoadd agreat dealofcold waterto make
thetemperaturesafeandcomfortableforcontact
withtheskin. Addingcoldto thehotwaterflowat
the tap reduces the flow of water through the
AquaStar causing the thermostat to reduce the
Btuinputor thewatervalve toshutoff iftheflow
through the AquaStar falls below 3/4 gallon/
minute. Werecommendsettingthetemperature
selectordial on#4 or#5. See sectionon Setting
WaterTemperature, Page12.
2. Unbalanced pressure in water lines
Theaddedrestrictioncausedby theAquaStarin
the hot water system can result in uneven pres-
suresbetweenthecoldandthehot. Insuchcases
whenmixingcold water atthetap, the lowerhot
waterpressuremaybeoverpowered bya much
highercoldwaterpresure,which maycause the
AquaStarburners toshutdown. Makesurefau-
cet aerators or shower heads are free of miner-
als. Checkthattheflowrestrictorandfilterofthe
AquaStarareclean
3. Cold water is mixing with the hot water
between the AquaStar and the outlet
Compare water temperature at outlet of the
AquaStar with the temperature at the tap. If dif-
ferent,checkforautomaticmixingvalveorplumb-
ing crossover (see #6, MAIN BURNERS WILL
NOT IGNITE) Where automatic "anti-scald"
valvesarerequiredbycode, lowerthe tempera-
turesettingontheAquaStarasmuchaspossible
and balance the pressure betwen cold and hot
waterafter theAquaStar.
4. Inlet water pressure is erratic due to inad-
equate supply water pressure or saturated
pressure tank on well system
Checktheinlet waterpressureandcorrectifnec-
essary.
Fig. 6 Temperature/Flow Chart AquaStar 80
FLOWSIN GALLONSPER MINUTE -based onground watertemperature of55ºF
*Rangedescribed abovewill belower ifinlettemperature isbelow 55ºF
Temperature chartofhot water
atdifferent flowrates with
selectoron position 8______
and position 2 _ _ _ _ _ _ _ _
1.0 1.5 2.0 2.5 3.0 3.5
F°
155
150
145
140
135
130
125
120
115
110
105
100
95
90
85
HOT WATER TEMPERATURE

19
PilotBurner
Hairpin
RetainingClip
Thermocouple
RetainingClip
PilotInjector
Pilot
FilterHousing
Gasket
Gasket
Filter
PilotTube
To Electromagnet
ToE.C.O.
Screen
Retaining
Clip
PilotBurner
PilotFlames
NOTE: Pilot flame must be
sharp blue, not soft and yellow
View of Pilot Flame
as seen from
above
Thermocouple
Screen Air Screen
Main
Burners
Screen
Thermocouple
PilotBurner
Retaining Bracket
CompressionRing
Pilot
Assembly
suspect that it might be partially obstructed. If you do
nothave a replacementorifice, you may blow through
it or use a non-residue aerosol cleaning agent (like
that used for electronics) can be sprayed through
the orifice.
5. Clean any combustion residue from the Pilot Burner
tip. Make certain that both holes and the slit are clean.
C. Reinstalling Pilot Burner to Main Burner Bracket
1. Insert injector into base of Pilot Burner. Reattach
Filter Housing to base of Pilot Burner, making sure
to have the Gasket in between.
Be certain that the brass Gas Pilot Filter Housing is
snug to the Pilot Burner — use two wrenches to
tighten.
2. Pilot holes face in towards Main Burners. Slide Pilot
Burner ALL the way up into the bracket.
a) Insert Hairpin Retaining Clip to hold Pilot Burner in
bracket. Pivot the Pilot Tube back into position below
FilterHousing.
b) Insert the other Gasket between tube and Filter
Housing.
c) Use two wrenches to tighten Pilot Tube to Filter
Housing.
1) One wrench should hold Pilot Burner in right most
position, making sure right side flame is aimed
precisely on tip of Thermocouple.
2) Use second wrench to tighten Pilot Tube nut — DO
NOTOVER-TIGHTEN
A. Removing Pilot
1.Hold Gas Pilot Filter Housing in place with one
wrench.
2. Unscrew Pilot Tube nut with second wrench.
3.Save the little white Gasket for reassembly.
4. Pivot the tube to the left (loosen base fitting if needed).
5.Removeupper“hairpin”retainingclip.
6. Pull Pilot Assembly downward out of bracket.
B. Cleaning the Pilot
1. Separate the chrome Pilot Burner from the brass Gas
Pilot Filter Housing. Save the white Gasket for
reassembly.
2. Examine the Filter material for dirt. Blowing from the
top gets the filter material out of the brass housing.
Since the material is layered; dirty layers can be
removed.Theremainingportionofthefiltercanbe
loosely reinserted into the housing. Do not pack the
material into the housing as this can obstruct gas flow
to the pilot.
3. Check that the Air-Pilot Screen is clean and
unobstructed.
4.The pilotinjector (orifice)mustnot beenlarged. The
natural gas orifice is large enough that you can
visually inspect andclean it. TheLP orifice, however,
is so small that it is difficult to inspect or clean. We
recommend that you change the LP orifice if you
CLEANINGTHEPILOT ASSEMBLY
AquaStarmodels80/125/170

20
Thermostat
Tubing to
Heat Exchanger
Calibration Screw
Thermostat
Piston
Assembly
Spring Correct height
of spring - 5/32"
or4mm
Note:Unless setting#8 (145°
±5,this isscalding hot water)
isneeded for somerare occa-
sionwehighlyrecommendrun-
ning the heater on setting 4 or
5.Thiswill alsoavoid theneed
to mix a lot of cold water.
1. Turn AquaStar temperature setting to #8. This is all the way to the right, clockwise.
2. Turn on a hot water tap at the flow which will turn the AquaStar burners on. If the heater is working
correctly, this minimum activation flow will be 3/4 of a gallon a minute, for Model 125/80 and 1.1 for
Model 170. This is a flow that can fill up a quart jar in 20 sec. for the Model 125/80 and 15 sec. for the
Model 170. If the necessary flow to activate burners needs to be higher than the required minimum, see
watervalve trouble shootingin your manual. Theburners will comeon at maximumfire and, withina
minute or so the burner flames will stabilize to a lower flame. Water temperature should be around
145°± 5. (This is scalding and too hot to put your hand under.) You should not be able to hold on to the
hot water pipe on the left side of the AquaStar.
3. Next turn the temperature dial all the way to the left to the lowest setting #2. Burner flames will become
quite small and should remain small. Water temperature, after a minute or so, should stabilize at about
105°±5. Holding the hotwater pipeshouldbe comfortable.
4. Leaving temperaturesetting at#2, now, increasewater flow onhigher. You shouldsee the burner
flamesincrease in size, andthen decrease whenyou reduce the waterflow.
5. Note: If all of the above performs according to this description, the thermostat is working correctly.
SYMPTOMS OF A DEFECTIVE OR IMPROPERLY CALIBRATED THERMOSTAT:
Thehot wateris toohot. Usuallythisresultsintheheater shuttingdown onoverheat
safety.Thepilotfrequentlygoesoutandneedstoberelighted.
PROCEDURE TO CALIBRATE THERMOSTAT
(See diagram for correct location of screw to recalibrate)
1.Turn calibrationscrew inclockwise allthe way,compressingthespring.
2.Backoutscrew11/2 fullturns. Whenset atthefactory, thespace fromtop to
bottom portionof the springshould be approximately5/32" or 4mm.
NOTE: Turningthescrewin(up) reducesthe burnerflames. Unscrewingitincreasesthe
flames.Ifathermostatis ingood condition,andthe calibrationscrew isproperly
adjusted,thewatertemperatureshould be145° (±5) whentemperaturedialsettingis
setat#8andwater isflowing atthe minimumburneractivatingflowof
3/4 of a gallon a minute (Model 125/80) or 1.1 gpm (Model 170).
NOTE: Sometimes as a thermostat gets old (5 yrs or so), the space on the screw
adjustmentmay betooloose.Inthat case,turn thescrewinanotherhalf orfull turnmore
ifneedbe.Itis importantthat youdo notbackthisscrewout sofar thatthe burner
flamesdo notmodulateandburnersare alwayson full.Withoutmodulation,theheater
willoverheatandshutdown.
TEST PROCEDURE TO CONFIRM THERMOSTAT IS WORKING PROPERLY
CALIBRATION AND THERMOSTAT TEST
Temperature Dial