AquaStar 38B LP User manual

WARNING: Improper installation, adjustment,
alteration, service or maintenance can cause injury
or property damage. Refer to this manual. For
assistance or additional information consult a
qualified installer, service agency or the gas supplier.
Uponcompletionoftheinstallation,theseinstructions
should be handed to the user of the appliance for
future reference.
INSTALLATION AND OPERATING INSTRUCTIONS FOR AUTOMATIC
INSTANTANEOUS TYPE WATER HEATERS FOR USE WITH NATURAL AND
LIQUEFIED PETROLEUM GAS
MODEL 38B LP and NG (Non Modulating)
Suitable for water (potable) heating and space heating
Intended for low flow domestic hot water applications with steady cold water inlet temperatures
WARNING
Iftheinformationinthismanualisnot 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
vicinity 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.
-Immediatelycallyourgassupplier 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
qualifiedinstaller, service agency or thegassupplier.
Specifications .................................................... Page 2
Rules for safe operation .................................... Page 4
Locating the Heater ........................................... Page 4
Combustion Air Requirements........................... Page 4
Mounting the Heater .......................................... Page 5
Venting the Heater............................................. Page 5
Gas Connections ............................................... Page 6
Water Connections ............................................ Page 6
Safety before lighting the pilot............................ Page 7
Lightinginstructions ........................................... Page 8
Setting water temperature ................................. Page 8
Maintenance & Service...................................... Page 9
Trouble Shooting ............................................. Page 10
Diagram of AquaStar ....................................... Page 13
Components and Parts List ............................. Page 14
TABLE OF CONTENTS
6 720 605 293 PT 862 (12.98)

2
This well engineered, gas water heater has all the fea-
tures a water heater should have:
Itoperates ontheprincipleofheating waterinstantaneously
“on demand”. When a hot water faucet is opened, cold
waterflows through the coilsof the heatexchanger in the
Aquastar. This same flow opens the gas valve, and the
burnersareignitedby the pilot flame. The heatexchanger
coils absorbtheheat generated bytheburners and trans-
fer heat to the water. When the hot water faucet is shut
off, the gas valve automatically closes and the burners
turn off. Your hot water faucet is an ignition key to turn on
the water heater, giving you control over your hot water
energyuse. Each timeyou turn off yourhot water faucet,
you also shut off the water heater.
FEATURES
- High Quality Materials for Long Working Life.
- Copper heating coils for endless supply of hot water.
- Safety thermocouple at pilot burner.
- Automatic overheating protection shut-off sensor.
- Stainless steel burners with stabilized blue flame.
- Built-in corrosion resistant draft inducer.
- Compactspacesaver:mountsonawallwithtwohooks.
- Easily removable one-piece cover.
- Easy one person installation.
- Adjustablewaterflowrestrictortoensurethatwaterflow
demand will not exceed the heating capacity of the
heater.
- Easypilotflame lighting withpushbutton piezo ignition.
AquaStar 38B LP and 38B NG Specifications
Gas Input max.: 40,000 Btu/hr
min.: 20,000 Btu/hr
Water Connection 1/2” Thread fitting
H x W x D 25 3/8” x 10 5/8” x 9 1/8"
Vent 4”
Gas Connection 1/2” NPT thread
Min. Water Pressure 13 Psi at 1.3 GPM
Max. Water Pressure 150 Psi
Shipping Weight 20 LB
Net Weight 18 LB
0.5 GPM at 90°rise
1.3 GPM at 45°rise
Min. Water Flow 1/2 gal/min
LP GAS Pressure inlet. min. 11” W.C.
max. 14” W.C.*
LP GAS Manifold pressure 9.0” W.C.**
Natural Gas Pressure inlet min.: 7” W.C.
max.: 14” W.C.*
Natural Gas Manifold Pressure 5.2 W.C.**
* Inlet gas pressure must not exceed this value
** For purposes of input adjustment
UNPACKING THE AQUASTAR HEATER
This heater is packed securely. The box includes two water connection fittings, a gas pressure regulator, two hooks for
hanging the heater, this manual, a personal letter, a warranty statement and a warranty registration card. Do not lose
thismanual, as thereis a chargefor replacement. Pleasecomplete and returnthe enclosed warrantyregistration card.

3
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, (d) maximum system water temperature must not exceed 140°F
(60°C). 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.
Open loop potable water and combination space heating system*
* To be used with a tank, check local codes. May not be permitted in some jurisdictions.
1. Maximum operating temperature of 38B: 140°F
2. Maximum heating capacity: 40°F rise 20°F rise
AquaStar 38B - 30,000 BTU/hr 15,000 BTU/hr
3. Systemshowniselectric storage tank with recirculatingsupplydrawnfromthe tapping for the lowerheatingelement.
4. Schematic is for illustration and example only and must not be used for actual installation without appropriate
engineeringand technical advicefroma professional properlylicensed in the localitywhere the installationismade.
Notes

4
GENERAL RULES TO FOLLOW
FOR SAFE OPERATION
1. You should follow these instructions when you install
your heater. In the United States: The installation must
conformwithlocal codes or, intheabsence of local codes,
the National Fuel Gas Code ANSI Z223.1/NFPA 54.
In Canada: The Installation should conform with CGA
B149.(1,2) INSTALLATION CODES and /or local
installation codes.
2. Carefully plan where you install the heater. Correct
combustion air supply and flue pipe installation are very
important. If not installed correctly, fatal accidents can be
caused by lack of air, carbon monoxide poisoning or fire.
3. The place where you install the heater must have
enough ventilation. The National Fire Codes do not allow
water heater installation in bathrooms, bedrooms or any
occupied rooms normally kept closed. See the section
below on locating the heater.
4. You must vent your heater. See section on Vent Pipe
Connections, Page 4.
5. The appliance must be disconnected from the gas
supply piping system during any pressure testing at
pressures in excess of 1/2 Psig (3.5 kPa).
Theappliancemust be isolated from thegassupplypiping
systembyclosing its individual manual shutoffvalve during
any pressure testing of the gas supply piping system at
test pressures equal to or less than 1/2 Psig (3.5Kpa).
Theappliance and itsgas connection mustbe leak tested
before placing the appliance in operation.
6. Keep water heater area clear and free from
combustibles and flammable liquids. Do not locate the
heater over any material which might burn.
7. Correct gas pressure is critical for the optimum
operation of this heater (see specifications on page 2).
Gaspipingmust be sizedtoprovide the required pressure
at the maximum output of the heater, while all the other
gasappliancesare in operation. Check withyourlocalgas
supplier,and see the section on connecting the gas supply.
8. Shouldoverheating occur orthe gas supplyfailto shut
off,turn offthe gas supply atthemanual gas shutoffvalve
on the gas line.
9. Do not use this appliance if any part has been
underwater. Immediatelycallaqualifiedservicetechnician
to inspect the appliance and to replace any part of the
control system and any gas control which has been
underwater.
PROPERLOCATION FOR INSTALLING YOUR
HEATER
Carefully select the location of your new heater. For your
safety and for proper heater operation, you must provide
anabundantsupplyofcombustionairandaproperventing
installation.
Theheatermaystilloperate even when improperly vented.
It will, however, be less efficient and could eventually
damagetheheater. Itcouldevenresult in human sickness
or death due to oxygen deprivation and carbon monoxide
poisoning. Follow the guidelines below:
1. Place your heater as close to a vent or chimney as
possible.
2. National building codes require that you do not install
this appliance in bathrooms, bedrooms, unvented closet
or any occupied rooms normally kept closed.
3. Simultaneous operation of other appliances such as
exhaustfans,ventilation systems clothes dryers, fireplaces
orwoodstoves couldcreateavacuumeffectin your home
which could cause dangerous combustion by-products to
spillbackintoyour home rather than ventingtotheoutside
through the flue. Confirm that your Aquastar is venting
properlywhenall these otherappliancesare running. See
section on venting.
Donotobstructtheflow of combustion and ventilation
air to the appliance. If installed near a clothes dryer it is
very important that the dryer be properly vented. Failure
to properly vent a dryer could result in a gradual
accumulation of lint on the water heater fin coils and
burners, leading to a dangerous condition of venting
blockage and poor unsafe combustion.
4. Yourhotwater linesshouldbekept shorttosaveenergy.
It is always best to have hot water lines insulated. Having
a floor drain or sink nearby is handy in case you need to
drain water from your heater.
WARNING: The water in this water heater is cold and
always remains cold exept for the times that hot water is
being used DO NOT INSTALL IN AN AREA WHERE IT
COULD FREEZE.
This heater is neither designed for nor approved for
outside installation.
WARNING: Flammable materials, gasoline,
pressurized containers, or any other items or articles
that are potentially fire hazards must NOT be placed
on or adjacent to the heater. The appliance area must
be kept free of all combustible materials, gasoline and
other flammable vapors and liquids.
COMBUSTION AIR REQUIREMENT
Observethefollowing instructions concerning combustion
air.
Appliances located in unconfined spaces:
a) An unconfined space is one whose volume is greater
than50 cubic feetper1000Btuper hour ofthecombined
ratingofallappliancesinstalled in the space. That would
be 2000 cubic feet for the AquaStar 38B alone.
b) Inunconfinedspacesinbuildings of conventional frame,
masonry, or metal construction, infiltration is normally
adequateto provide air forcombustion, ventilation, and
dilution of flue gasses.

5
Appliances located in confined spaces:) The confined
space must be provided with two permanent openings,
one commencing within 12 inches of the top and one
commencing within 12 inches of the bottom of the
enclosure.Each openingmust have a minimum freearea
of one square inch per:
- 1000 Btu/hr if all air is taken from inside the building.
- 2000Btu/hr ifallairistaken fromtheoutsidebyhorizontal
ducts.
- 4000 Btu/hr if all air is taken from the outside by direct
openings or vertical ducts.
Louvers, grills and screens have a blocking effect. If the
effectivefreearea is not known,increase the sizes ofyour
openings by 75% if your louvers are wood and by 30% if
your louvers are metal. Refer to the National Fuel Gas
Code for complete information. In buildings of tight
construction all air should be taken from outside. That
would be 2000 cubic feet for the Aquastar 38B alone.
CLEARANCES
The Aquastar 38 B is design certified for installation on a
combustible wall and for installation in an alcove or closet
with the minimum clearances to combustible and non -
combustible construction listed below
A. Top 12 inches ( 305 mm)
B. Front 4 inches (102mm)
C. Back 0 inches
D. Sides 4 inch (102mm)
E. Bottom 12 inches (306 mm)
Clearance from vent is dependent upon the clearance
ratingof the ventingmaterial used. Forexample: type B-1
vent is approved for 1 inch clearance, B-2 vent for 2 inch,
etc.
Note: Minimumclearancetocombustiblematerialsshould
not be less than 6" for single wall flue pipe. Note that this
clearance can be reduced if combustible material are
protected as per table VI of the National fuel Gas Code or
if Type B gas vent is used.
MOUNTING INSTALLATION
The Aquastar 38 B is design certified for mounting on a
wall.
Do not install this appliance on a carpeted wall or over
floor covering which is combustible, such as carpet. The
heater must be mounted on a wall using appropriate
anchoring materials. If wall is a stud wall sheathed with
plasterboard,it is recommended that support board(s),
either 1x4’s or 1/2" (minimum) plywood first be
attached across a pair of studs and then the heater
should be attached to the support boards. See Fig 1.
Expansionandcontractionofpipingduetochangingwater
temperature in the pipes imparts movement to the heater
which, if mounted directly to a brittle, friable board, such
as plasterboard, can cause failure of mounting.
Before installing the unit, be certain you have the correct
heater for your type of Gas – Propane or Natural Gas.
Fig. 1 - Mounting the Heater
Identificationlabels are foundonthe shipping box,and on
the rating plate which is located on the right side panel of
thecover.Also, each burner orifice isstampedwithanum-
ber (79 for LPG and 120 for Natural Gas).
VENTING
Vent pipe connection.WARNING: Do not reduce the
vent pipe size.
This appliance must be vented to the outside following all
local ordinances and specifications for installing a gas
appliance vent or chimney. The venting system must be
designedand constructed soasto develop apositive flow
adequatetoremove flue gasses totheoutdoors.Minimum
vent size must be 4". Minimum height must be 6 feet,
provided there are no elbows. Termination of vent
must be 2 feet above any obstruction within a 10 foot
radius. Consult your gas utility or National Fuel Gas
Code if vent will have elbows or share venting with
another appliance. The vent connector should have
asmuch vertical rise as possible(minimum12”) before
any horizontal run. The appliance must be located as
close as practicable to a chimney or vent. The vent pipe
sections must be secured to each other with sheet metal
screws. Keep in mind the minimum clearance from the
top of your heater. Remember also that single wall vent
pipe connectors require a 6 inch clearance from
combustibles. National Fuel Gas Code specifies double
wall — Type “B” — vent pipe be used in cold climates and
for gas vents running through attics. We consider double
wall vent pipe preferable in all circumstances. Any vent
sectiongreaterthan45degreesfromverticalisconsidered
horizontal. Horizontal sections of vent connectors must
slope upwards at least 1/4 inch for every foot of its
horizontal length. Keep the horizontal section short and
avoid too many elbows.
WALL STUDS
1” X 4”
SPACE BOARD
SUPPORT BOARD
5 ½”

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WARNING
Note:Theburnersofaninstantaneous“ondemand”water
heater such as the AquaStar are only on at the time that
hot water is actually being used, the venting stack is
thereforecold except fortheshortdurationswhen hot water
isbeingused,itisthereforeveryimportantthat theventing
and air supply be adequate to provide a good positive
draft as soon as the burners turn on.
TheAquaStar38Binstantaneouswater heaters have built-
in draft diverters and are designed for indoor installation
only. The draft diverter outletmustbeconnectedtoaclear,
unobstructed vent of the same size, or larger.
In Canada, CAN/CGA-B149 Installation Code for
detailed requirements
In U.S.A., ANSI Z223.1 - NFPA 54, national Fuel Gas
Code for detailed requirements.
GAS CONNECTIONS and Gas Regulator
Before connecting the gas supply, check the rating plate
ontherightsideofthefrontcovertobesurethattheheater
is rated for the same gas to which it will be connected.
In the United States: The installation must conform with
local codes or, in the absence of local codes, the National
Fuel Gas Code ANSI Z223.1/NFPA 54.
InCanada: The InstallationshouldconformwithCGAB149
INSTALLATION CODES and /or local installation codes.
NOTE: The Aquastar 38 B is supplied with a gas
pressureregulatorthatmustbeinstalledontheheater
before attaching the gas supply line. See figure 2.
Place the gas regulator between the gas supply
connection (wich comes with a manual shutoff valve)
and the gas fitting wich is connected to the heater’s
gas inlet. There is a pressure test nipple on this gas
fitting. The regulator supplied with the heater is preset
for the gas shown on the rating plate to the correct
pressure. It is an appliance level regulator designed
for (low inlet) pressure (less than 1/2 Psig or 15” W.C.)
DO NOT connect to an unregulated or high pressure
propane line or to a high pressure commercial natural
gas line.
NationalFuelGasCoderequiresthatasediment trap (drip
leg) be installed on gas appliances not so equipped. The
drip leg must be accessible and not subject to freezing
conditions.Install in accordancewiththerecommendations
of the serving gas supplier.
WARNING: The heater and its individual shutoff valve
must be disconnected from the gas supply piping
system during any pressure testing of that system at
test pressures in excess of 0.5 psig.
The water heater must be isolated from the gas supply
piping system by closing the manual shutoff valve during
any pressure testing of the gas supply piping system at
test pressures equal to or less than 0.5 psig.
Thewater heater,includingthepressure regulator provided
with it, must not be operated at gas supply pressures in
excess of 0.5 psig. If overpressure has occurred, such as
through improper testing of the gas lines or emergency
malfunction of the supply system, the gas valve and
regulator must be checked for safe operation. Make sure
thattheregulator vent is protected againstblockage. Vent
blockage could occur during ice storms.
When your connections are made, check for gas leaks at
all joints (not just the ones you made). Apply some soapy
water to all gas fittings and gas valve. 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, shut off the gas. After
verifying that required gaskets are in place, tighten
appropriatefittingstostopleak. Turnthegason and check
again with a soapy solution. Never test for gas leaks
using a match or flame.
WATER CONNECTIONS
Although water piping throughout your structure may be
other than copper, we recommend that copper piping be
used for at least three feet before and after the heater
(followlocalcodesif more stringent). Keep waterinletpipe
Thepressureregulator provided with the heater isadjusted
to deliver the proper gas pressure (as indicated on the
rating plate and in the manual for altitude up to 2000 feet
(660 meters) above sea level. On appliances being
installed above 2000 ft (660 meters) elevation, the inlet
gas pressure should be set at installation to the value
shown below.
NOTE: The gas pressures specified below refer to
pressures taken at the test pressure nipple on the gas
inlet pipe just above the regulator (See Fig 2). These
readings should be taken while the heater is operating
at full input — i.e. maximum water flow with the
temperature dialselector turned all the way clockwise.
MAXIMUM INLET GAS FLOW PRESSURE SETTING
PRESSURE REGULATOR
Fig. 2 - Gas Pressure Regulator
Above 4.500 ft consult your local gas supplier.
Altitude Natural Gas Liquid Propane
inches W.C: inches W.C:
0' - 2.000 ft 5.7" 10.5"
2.000 ft - 4.500 ft 4.6" 8.5"

7
Fig. 3 - Water valve, top view
Connecting the pressure relief valve (PRV)
Alistedpressure relief valve supplied withtheheatermust
be installed at the time of installation. Should a discharge
linebeadded to thePRVnovalve is to beplacedbetween
the PRV and the heater. No reducing coupling or other
restriction may be installed in the discharge line. The
dischargeline mustbeinstalledsuchthat itallowscomplete
drainage of both the PRV and the line. The location of the
PRV must be readily accessible for servicing or
replacement.,andbemountedas close to the water heater
as possible See Fig 4. To install the PRV, a suitable fitting
connected to an extension on a “T” fitting can be sweated
to the hot water line.
Fig. 4 - Pressure Relief Valve
WATER VALVEWATER FILTER
COLD WATER
INLET
to no less than 1/2 inch diameter to allow the full flow
capacity. Threadedconnectorsaresuppliedwiththisheater
forboththehotand cold water fittings. These fittings permit
1/2”NPT connections tobemade. Be certainthere are no
loose particles or dirt in the piping. Blow out or flush the
linesbefore connecting totheAquaStar. Aballvalveshould
beinstalledonthecold water feed line to facilitate servicing
the heater.
For installation on a private well system, be sure that the
water pressure is set between 30 and 50 psi.
OPERATING INSTRUCTIONS
Before proceeding with the operation of the heater make
sure that the system is filled with water.
Makesure the waterheaterdrainplugis closed. SeeFigure
5 below.
Fig. 5 - Water heater drain plug
Open the cold water inlet supply to the heater fully.
Openahotwaterfaucet to permit the water to fill the heater
andthe piping andtoeliminatetheair trapped inthesystem
Closethe hot waterfaucet after thewater flows freelyand
allthe air hasescaped from thesystem. The waterheater
is now ready to work
FOR YOUR SAFETY READ BEFORE
LIGHTING THE PILOT
A. Thisappliance has a piezo-igniter forlighting the pilot
burner. When lighting the pilot, follow these instructions
exactly.
B. BEFORE LIGHTING smell all around the appliance
area for gas. Be sure to smell next to the floor because
some gas is heavier than air and will settle on the floor.
WHAT TO DO IF YOU SMELL GAS
- Do not try to light any appliance.
- Do not touch any electric 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.
C. Use only your hand to push in or turn the gas control
buttons.Neveruse tools. Ifabutton will not pushin,check
to make sure the buttons are being pushed in the proper
sequence. Follow these instructions exactly. If control
button(s) are jammed, close the gas supply and call a
qualifiedservicetechnician.Attempted forceful repair may
result in a fire or explosion.
D. Do not use this appliance if any part has been under
water. Immediately call a qualified service technician to
inspecttheapplianceandto replace any part of thecontrol
system and any gas control which has been under water.
WATER VALVE
DRAIN PLUG
TO HEAT
EXCHANGER

8
Fig. 6 - Water Flow Control Knob
Whatis the best temperaturesetting? Because AquaStar
waterheatersdeliverendlesshot water at the temperature
you have selected, there is no need to produce very hot
water and then mix in cold. It just does not make sense to
overheat water and then mix in cold to cool it off. You
cannot run out of hot water with an AquaStar, so set the
dial for the temperature you prefer. Note: 105°F is the
maximum recommended for a hot bath. The position you
select on the temperature adjustment knob will depend
onthetemperatureoftheincomingwater (50°Fisaverage
in the U.S.). If you plan to supply the AquaStar 38 B, with
preheated water (i.e.) solar installation, the unit could
overheat. It will then shut off on safety when the outlet
temperaturereaches 185°F. Foralower temperature rise,
theheatercan be set for minimumburneroutputby sliding
the gas valve control to the pilot setting symbol ( ).
LIGHTING INSTRUCTIONS
1. STOP! Read the safety information on the front panel
of the heater.
2. The Gas valve must be turned off by sliding the gas
valvebutton ( )to the far left underthe OFF( ) mark.
3. Wait five (5) minutes to clear out any gas. If you smell
gas, STOP! Follow “B” in the safety information above
on this plate. If you don’t smell gas, go to next step.
4. The pilot burner is located behind the peephole in the
front center of the jacket directly below the lighting
instructions on the front panel of the heater.
5. Slidethe gas valvebuttontotheright,tothe pilot position
( ).
6. Fully depress gas valve button ( )and light pilot by
pressing hard on pilot igniter button ( ). This step
may have to be repeated.
7. Observe the pilot flame through the peephole. The gas
valve button should be held down at least 10 seconds
withpilot burning.Whenthegasvalve buttonisreleased,
the pilot should continue to burn.
- If the gas valve button does not pop up when released,
stopandimmediately call yourservicetechnician or gas
supplier.
- If pilot does not stay lit, repeat steps 1 through 7.
- If pilot will not stay lit after several tries, slide the gas
valvebutton to theleft,under the OFF( ) mark and call
service technician or gas supplier.
8.When thepilot remains on, slidethe gas valvebuttonto
the right, to the ON ( ) position. The heater will now
fire when water is drawn at a rate of 1/2 gallon or more
per minute.
NOTE: If main burner should fail to ignite, make sure pilot
is burning. If not, repeat lighting steps 1 through 7.
TO TURN OFF GAS TO APPLIANCE
Slide the gas valve button ( ) to the far left, under the
OFF ( ) mark and close the heaters individual shut-off
valve.
SETTING THE WATER TEMPERATURE
Toadjust the temperatureon your AquaStar,turn on ahot
water faucet to its maximum flow. At the water heater,
turn the large temperature adjustment knob located
beneath the main gas controls on the front of the heater
all the way to the right (clockwise). See Fig 6. This will
produce a temperature rise of approximately 90oF at a
flow rate of .5 gallons per minute (gpm). Turning the dial
all the way to the left (counterclockwise) will increase the
water flowing through the heater, and will produce a
temperature rise of approximately 45oF at a flow rate of
1.3gpm.Giventhataverageincomingwatertemperatures
are 50oF, this heater will produce water between 140o
and 95o at these flow rates. Thus one can obtain a higher
flow rate, but at cooler temperatures.

9
Fig. 8 - Pilot burner with air screen/ pilot orifice
Fig. 7 - Characteristic Pilot Flame
MAINTENANCE AND SERVICE
Approximately once a year, the AquaStar should be
checked, cleaned and serviced as necessary. To remove
thefront cover, first removethe incandescent particle tray,
then pull off the temperature adjustment knob, unscrew
and remove the plastic collar and unscrew the central
screw located at the bottom of the front cover. Pull main
coverout toward youandliftupandout.THE FOLLOWING
OPERATIONS SHOULD BE PERFORMED BY A
QUALIFIED SERVICE PERSON:
Vent System: Should be checked annually. Clean and
repair as needed.
Water Valve (Part # 8707002497): The water valve on
this heater should be serviced periodically The frequency
will depend on the mineral content of the water and
conditions of use or whenever signs of corrosion appear
atthe gas andwater valve joint.Checkthat the waterinlet
filter (#25 on Figure 10, page 14) is clean.
Pilot Flame: Thepilotflameshouldburnwith a cleansharp
blue flame and should resemble the diagram in Fig 7. If
the flame is yellow, or if the pilot knob has to remain
depressedfora long timeinorder to keep thepilotlighted,
the pilot burner and or the pilot burner orifice may need to
be cleaned, the orifice may need to be replaced, and or
the air screen or pilot gas filter may need cleaning. The
pilot flame should envelop approximately 10 mm (3/8") of
thetipofthethermocouple.Ifitis too small, the pilot burner
mustbe cleaned. ThepositionofthePiezoigniterelectrode
should be approximately 3 mm (1/8") from the pilot.
To clean the pilot burner and/ or the pilot orifice : Turn
offthe gas at theunit. Remove thecover of theheater. To
do so, remove the incandescent particle tray, pull off the
temperature adjustment knob and unscrew and remove
the knob collar. Unscrew the central screw located at the
bottom of the front cover. Pull main cover out toward you
andlift up andout.Pull the airscreen off,washit and blow
any lint off (See Fig 8). The pilot orifices should also be
cleaned or replaced. Do not enlarge the orifice. Do not
use any wire or sharp object to clean orifices. Natural gas
orifices are large enough that you can usually clean them
by blowing through them. LP orifices, on the other hand,
are too small to clean and should be replaced. See #3 in
Trouble Shooting Section. To access the pilot orifice,
remove 2 screws holding pilot assembly in place. Then
loosen compression fittings to expose pilot orifice.
Main Burner Flames: The main burner flames should be
blue, with a more intense blue cone in the center core.
Yellowflames could beasign of wrongsizegas orifices or
dirty burners, or a blockage on the heat exchangers fins.
Ifsomeburners have yellow flameswhileothershavegood
flames,itis likely that dust, lint orspiderwebshavepartially
clogged the burner venturis. To clean the burners contact
a gas service person.
Mineral Scale Build-up: AquaStars, when operated at
lowertemperaturesettings, tend not to accumulate mineral
buildup. If however, the heater is used at the higher
temperature settings and the water has a high mineral
content,periodic descaling may benecessary.The heating
coilsshould be flushed witha descaling solution.Consult
your dealer or Controlled Energy for instructions.
PILOT ORIFICE
AIR SCREEN
3mm
Correct gap between pilot
burner tip and electrode tip
Piezo Electrode
Air screen filter
10mm
3/8”
Piezo
Electrode
Thermocouple

10
TROUBLE SHOOTING
Introduction
TheAquaStar38burners are ignitedbyawater flow valve.
Numerous water related problems can cause this water
valvetomalfunction such as: Insufficient waterflowvolume
to activate the burners at its minimum flow requirement;
Dirt in the water flow valve causing it to malfunction;
Sediment build-up in faucet aerators, or shower heads;
Unevenpressuresbetweencold and hot.(withsinglelever
faucets) Plumbing cross overs. These water flow related
problems can cause the heater to deliver less than its full
output, or to fail to ignite or to shut down completely.
Problems are stated in upper case, bold face. Most
common causes for the problems follow in order of
likelihood.The suggested solutions require thatthe cover
be taken off. To this, remove incandescent particle tray,
pulloffthe temperature adjustmentknobandunscrewand
remove the plastic collar and unscrew the central screw
located at the bottom of the front cover. Pull main cover
out toward you and lift up and out.
1. No gas to the Aquastar
A. Gas cock on gas line may not be open.
B. Gas valve button has not been moved to “PILOT
POSITION”.Slidebutton to right tosingleflameposition
( ).
2. In-line Aquastar gas regulator jammed (usually on
LP gas)
Replace or unjam the regulator. Note: The regulator
furnishedwiththwheaterisdesignedforlowgaspressure.
Excessivepressurewilllockitup(propaneonly). Jamming
usuallyhappens if thegas pressure betweenthegas tank
(propane) and the water heater’s gas regulator has not
beenreduceed.See page 2 for recommendedcorrectgas
pressure and check with gas service person.
3. Pilot orifice clogged and/or air screen dirty
Clogging of the pilot burner can be caused by dust and
any suspended matter contained in the ambient air.
Although the filters can lengthen the cleaning intervals,
they can never completely prevent such clogging. In
consequence the gas jet issuing from the pilot orifice is
reduced and or the air mixture is reduced. The pilot flame
is weak and thus can no longer heat the thermocouple
sufficiently. For cleaning purposes, the air filter screen is
pulled off, washed and blown out. The pilot orifice has
likewise to be cleaned or exchanged. Consult Controlled
Energy or a gas service person.
4. Air in the Gas Line
Note: Normally this is a problem only at the time of initial
installation, after the pipes have been worked on, or after
a propane tank has been allowed to empty, or after the
heater has been shut down for a long time.
Bleed all the air trapped in the gas line. Because of the
very small pilot orifice (especially on LP gas models),
bleeding out all the air could take several minutes. Slide
the gas valve button ( ) to pilot position ( ) and depress
this button until all the air has escaped, and the gas has
arrived. During this process, press on the piezo ignition
button separately until the pilot flame has ignited.
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
Slide the gas valve button ( ) to pilot position ( ) and
depress this button. Hold it pushed in for at least 15
seconds to give time for the pilot flame to properly heat
the tip of the thermocouple.
2. Pilot flame improperly aimed or is too weak so it is
not properly heating the tip of the thermocouple.
The Pilot flame should be a sharp blue flame and aimed
at the tip of the thermocouple so that it envelops 10 mm
(3/8“) ofthethermocoupletip.Pilot flamehastobeproperly
aimed at the thermocouple. See Fig 7.
3. Poor thermocouple connection at the
electromagnet
Note: Electromagnet is part #8707201012 located on the
right side of the gas valve behind the piezo pushbutton
assembly. Check the tightness of the thermocouple
connectionnut at theelectromagnet: The Electro-magnet
connection is a large aluminum 17mm hex head nut. The
thermocouple end is a 5 mm brass nut which screws into
the 17 mm nut. Tighten the thermocouple nut snugly but
not too tight.
4. Poor circuit connections at the ECO. (Energy Cut-
Off overheat protection)
Oxidation or looseness of the ECO terminal connections
canresultinmillivoltcurrent loss through the thermocouple
safetycircuit. Clean terminals withvery fine sand paperor
an eraser and reconnect ECO leads.
5. Faulty ECO (part #8707206040)
If cleaning the terminals attached to the ECO did not fix
the problem,connectajumperwirebetweenthetwowires
and try to relight the pilot. If the pilot flame now remains
on, replace the ECO. If the flame still goes out when the
button is released, the ECO is not defective. Go to next
step.
6. Faulty thermocouple (part #8747202083) or
electromagnet ) Unless these 2 parts are at least 8
to10 years old, it is very unlikelythatthey are faulty.
Before testing, reconfirm that #2 is absolutely
correct,and that all connections arecleanand tight.
To test the thermocouple, disconnect the thermocouple
lead to the ECO. Insert a multi-meter probe on the
thermocoupleECOconnection and attach the othermeter
lead on the spade connector of the ECO. Light the pilot
flame, and take a reading on the meter. If it reads less
than 24mv, replace the thermocouple. If the reading is
24mvoroverthethermocoupleisgood.To test the electro-
magnet,takeanotherreadingacrosstheECOspadewhile
the pilot flame is on. The reading should drop to about 15
mv. If it does not and remains unchanged, replace the
electromagnet.

11
BURNERS DO NOT IGNITE WHEN HOT WATER IS
TURNED ON
1. Pilot is not on.
Light the pilot. See lighting instructions.
2. Pilot lighting push button not turned to proper
position
Be sure that once the pilot flame is on, that the gas valve
button( )is slid alltheway to theright to the ON position
( ).
3. Cold incoming water connection made to wrong
side of heater
Make sure cold water inlet connection is on the right side
of heater when you are facing heater.
4. Water flow rate at hot water tap is too low.
Note: The AquaStar models 38 B require 1/2gallon per
minute flow to activate the burners. This is a flow which
would fill a quart jar in 30 seconds.
5. Cold water inlet filter on heater is dirty.
Remove the filter and clean. This screen filter is located
at the inlet side of the brass water valve (fig. 10, #25).
Check and clean faucet aerators too.
6. Crossover in household plumbing
The AquaStar burner activates when there is sufficient
waterpressuredropintheAquaStarwatervalveassembly
— ie. when a hot water faucet is opened. If there is a
crossover in the plumbing, the necessary pressure drop
in the AquaStar will be insufficient, or totally eliminated. A
plumbing crossover can be caused by a bad washer at a
singlelever faucet orincorrect plumbing ora mixing valve
in the line, etc. which permits hot and cold water to mix in
the plumbing. The crossover will create a back pressure
inthesystempreventingthepressuredropin the Aquastar
(i.e.coldwaterisentering the water heater from bothsides
and the burners will not come on). To confirm there is no
crossover in the plumbing, shut off the cold water supply
to the AquaStar. Open your hot water taps. There should
not be any water flowing. If there is water flowing, there is
a crossover in the plumbing. This is a plumbing problem,
not an Aquastar problem. Please contact your plumber.
7. Water valve parts may be dirty or components
damaged.
Water valve and component parts must be totally free of
dirt. First check that the venturi is free of dirt particles. In
hard water areas, mineral deposits can eventually (3 to 5
years in hard water areas) corrode the water valve parts
to a point where they will need replacing. Any sign of
moisture or corrosion at the joint of the water valve and
the gas valve is a sign that the water valve assembly
componentsneedto be replaced immediately .Note: Water
valve for model 38B is part# 8707002497 for both LP and
NG models. (Contact service person to clean water valve
or replace if corrosion is present).
PILOT LIGHT GOES OUT DURING OR IMMEDIATELY
AFTER HOT WATER HAS BEEN USED
1. Gas pressure too low
Very low gas pressure may be caused by low delivered
gas pressure, a jammed gas regulator or undersized gas
lines.If the gas linesare undersized, there maystillbe the
specifiedstaticgaslinepressure.Howeverwhenthewater
valveopens,and gasenterstheburners,the pressurecould
dropsharply,causingthe pilot flameto go out. Havea gas
technician confirm the gas pressure both static and at
maximum Btu output. Specifications for your heater are
on page 2.
2. Pilot may be dirty or weak
See Page 9 for instructions on pilot maintenance.
3. Burners are not shutting down immediately when
hot water is turned off
Note: If burners don’t shut down immediately when the
hot water is turned off, the heater will overheat and the
ECOwill shut-offthe gas.Rebuildthewatervalve assembly
repair kit from CEC (part#8 703 406 204).
4. Water is too hot causing overheat sensor to shut
heater down
Reduce burners by sliding gas control to single flame
position.
WATER IS TOO HOT
1. Burners too forceful
Note:Iftheinletwater is quite warm, slide gas valve control
to single flame symbol ( ) and the heater will function on
a minimum burner output.
2. Temperature selection is too hot
Turn the temperature adjustment knob to the left.
WATER IS NOT HOT ENOUGH
1. Temperature adjustment knob is set too low.
Changethesetting.Turn the temperature adjustment knob
clockwise (to the right).
2. Water flow through the heater is higher than the
capacity of the AquaStar to heat it
Reduce the flow demand at the faucet. See flow rates at
specific temperature rises on page 2.
3. Btu input istoolowdueto insufficient gas pressure
It is extremely important for a tankless
instantaneous water heater to have the right size
gas line to obtain the correct gas pressure
See specifications on page 2. Unlike storage tank water

12
heaters, the burners of a tankless water heater must be
verypowerful to heatwater instantaneously sincetheydo
this only at the time hot water is actually being used. It is
therefore imperative that the gas pressure requirement
bemetexactly. Insufficientgas pressure will directlyaffect
the water temperature at the time of usage. See pages 2
and 13 respectively for correct gas pressure settings and
where gas pressures are taken.
4. Btu input is too low due to insufficient gas supply
Make sure your main gas line is fully opened. If using LP
gas, be sure that the size of the propane tank is adequate
to supply the required gas pressure.
5. Cold water is mixing with the hot water between
the AquaStar and the outlet
Comparewatertemperature at outlet of the AquaStar(hold
the AquaStar’s outlet pipe with your hand) and at the tap.
If these two are very different, check for mixing valve or
plumbing crossover (see “MAIN BURNERS WILL NOT
IGNITE...” paragraph #6). Where automatic “anti-scald”
valvesarerequiredby code, lower the temperaturesetting
on the AquaStar as much as possible and balance the
pressure between cold and hot water after the AquaStar.
6. Parts in water flow valve are corroded so that the
gas passage is not fully opening.
Contact your service person or Controlled Energy.
HOT WATER TEMPERATURE FLUCTUATES
1. Unbalanced pressure in waterlines
The added restriction caused by the Aquastar in the hot
watersystem can result inuneven pressures between the
coldand the hot.In such caseswhen mixing coldwater at
thetap,thelower hot water pressure maybeoverpowered
by a much higher cold water pressure, which may cause
the Aquastar burners to shut down. Make sure faucet
aerators or shower heads are free of minerals. Do not
add any flow restrictor to the shower head.
2. Cold water is mixing with the hot water between
the AquaStar and the outlet
See #6 under “Burners do Not Ignite When Hot Water
Turned On”.
3. Inlet water pressure is erratic due to inadequate
supply water pressure or saturated pressure tank
on well system
Check the inlet water pressure. On a private well, raise
minimum pressure setting to 30 psi. Confirm that the
pressure tank is not water logged.
4. Insufficient gas pressure
Check gas pressure requirements (page 2) and consult
gas service person.

13
Fig. 9 - Diagram of AquaStar 38 B
2
4
8
10
1
7
9
11
1. Heat exchanger
2. Pilot assembly
3. Burner manifold gas
pressure test nipple
4. Pilot gas tubing
5. Main gas burner
6. Inlet gas pressure test nipple
7. Gas valve
8. Gas control slide
9. Piezoigniter
10. Temperature adjustment knob
11. Water valve
3
5
6

Fig. 10 - INTERIOR COMPONENTS DIAGRAM AND PARTS LIST

Fig. 10
INTERIOR COMPONENTS DIAGRAM
AND PARTS LIST 38B
1Cover ¤ 8 705 421 021
2Temperature adjustment knob ¤ 8 702 000 182
3Panel back ¤ 8 705 402 170
4Draft divertor ¤ 8 705 505 361
5Heat exchanger ¤ 8 705 406 233
6Overheat sensor (ECO) ¤ 8 707 206 040
7Hot water pipe ¤ 8 700 703 038
8Main burner assembly LPG 8 708 120 301
Main burner assembly NG 8 708 120 011
9Burner assembly washer ¤ 8 710 103 008
10 Piezo electrode ¤ 8 708 107 002
11 Pilot burner assembly ¤ 8 718 105 048
11a Pilot air screen ¤ 8 700 507 055
12 Pilot orifice NG 8 708 200 005
“ LPG 8 748 200 173
13 Pilot Tube ¤ 8 700 707 334
14 Thermocouple ¤ 8 747 202 083
15 Gas valve LPG 8 707 011 456
Gas valve NG 8 707 011 466
16 Electromagnet ¤ 8 707 201 012
17 Thermocable ¤ 8 747 202 209
18 Water valve assembly ¤ 8 707 002 497
19 Water valve repair kit ¤ 8 703 406 204
20 Water valve diaphragm ¤ 8 700 503 050
21 Slow ignition valve ¤ 8 708 503 061
22 Water valve water governor ¤ 8 707 402 012
23 Water valve selector screw ¤ 8 708 500 166
24 Holding bracket ¤ 8 701 309 040
25 Water inlet filter ¤ 8 700 507 001
26 Water valve venturi ¤ 8 708 205 210

GAS LINE SIZE
Natural Gas
Nominal Iron Pipe Size* 3/8" 1/2"
MAXIMUM LENGTH 20' 80'
Liquid Propane
Semi-rigid Tubing 3/8" 1/2"
MAXIMUM LENGTH 10' 60'
* Flex tubing greatly reduces capacity and, therefore, is not recommended.
Minimum Vent Size* and Height
Minimum Diameter Minimum Height**
4 inches 6 feet**
* NOTE: Vent size must not be restricted. Installation must comply with national fuel
g
as code ventin
g
requirements
for a 40,000 Btu Cate
g
ory I appliance and any applicable local codes.
Water Pressure
For installation on well systems, insure that your water pressure is between 30 - 50 psi.
** NOTE: 6 feet, provided there are no elbows. Termination of vent must be 2 feet above any obstruction within a
10 foot radius. Consult your
g
as utility or National Fuel Gas Code if vent will have elbows or share ventin
g
with
another appliance. The vent connector should have as much vertical rise as possible (minimum 12") before any
horizontal run.
INSTALLATION CHECKLIST
Replacement Parts available from North American Distributor
CONTROLLED ENERGY CORP.
340 Mad River Park
Vermont 05673 (U.S.A.)
Phone [phone]
Fax [phone]
WWW.CECHOT.COM
VULCANO Termodomésticos S.A.
Estrada de Cacia
3800 Cacia - PORTUGAL
Recycled paper
[email protected]