AquaStar 125BL User manual

INSTALLATIONANDOPERATINGINSTRUCTIONS
FORAQ-1 POWER VENT KIT
DESIGNED FOR
BOSCH 425 HN WATER HEATERS
AQUASTAR 125B WATER HEATERS
INCLUDINGAQUASTARMODELS: 125HX•125BS • 125X • 125BL
TABLE OF CONTENTS
contentswith anAQ-1powervent p.1
mountinggas pressureswitch p.2
mounting linear spillage switch p.4
commonsetup p.6
locating vent hood (clearances) p.7
mountingpowervent motor(clearances) p.7
troubleshootingandmaintenance p.9
safety interlock test p.10
AQ-1wiringdiagram p.11
venthoodtemplate p.12
8504077 rev. B 10.03

AQ-1Powerventkit
Partsincluded:
Spillage Switch Kit
1. 185º F linear spillage switch mounted on an
angledbracket andequipped with36 inch
cables connected to one eyelet terminal
and one 1/4" quick connect terminal
2. Spillageswitch mountingscrew
3. Pushon malespade connector,replaces
eyelet terminal from 36 inch spill switch cable.
Vent Hood Kit
1. 4"venthood: VH1-4
2. Plastic wall anchors (4)
3. Sheet metal screws (4)
4. 5" to 4" vent reducer pipe
5. AQ1FLAPPER back draft accessory
Vibration Mount Packet
1. Vibrationmounts (2)with nuts and washers
2. Brackets (2) with nuts and washers
Gas Pressure Switch Packet
1. Gaspressure switch
2. Self-tappingmountingscrews (4)
3. Manifoldpressure tapfitting with 1/4" com-
pressionnutand sleeve
4. 1/4" by 40" aluminum tubing (2)
Power Vent Kit
1. Powerventer(HSUL-1Series containing
integrated24v controlcircuit) including 25
foot control cable with 1/4" quick connect
endsand anHPN 6 foot power cord
2. Nylon ties
1

Power Vent Kit
CAUTION
1. Failure to install, maintain and/or operate the
Power Venter in accordance with
manufacturer's instruction may result in
conditions which can produce bodily injury and
property damage.
2. The Power Venter must be installed by a
qualified installer in accordance with all local
codes or, in their absence, in accordance with
the National Fuel Gas Code (ANSI
Z223.1NFPA #54), the National Electric Code
andThe OccupationalHealth and Safety Act
(OSHA)as applicable.
3. The Power venter motor shaft must be
mountedhorizontallyto preventmotorbearing
wear.
4. Disconnect power supply when making wiring
connections or when working around the fan
blade and motor. Failure to do so may result
in severe personal injury and equipment
damage.
5. Make certain the power source is adequate for
the fan motor requirements. Do not add the
power venter to a circuit where the total load
isunknown.
AQ-1 Motor is 200 watts- 1.66 amps @ 120vac
Bosch-Aquastar
1. Followinstallation andoperating instructions
manualsupplied withthe water heater.
2. Beforemounting waterheater to wall, check
itsminimum clearancerequirements.
3. When using an AQ-1 the maximum
horizontaldistance from the water heaterto the
power vent motor is 100 feet. Subtract 10 feet
for each added elbow. Install power vent
motor as close to the termination as
possible to maintain the water heater's
optimal efficiency.
IMPORTANT: FREEZE PREVENTIONTOHEATER
In cold climates the vent hood and power vent mo-
tor will not prevent infiltrating cold air to the water
heater when not in use. Be sure to install the sup-
plied backdraft AQ1FLAPPER accessory within the
vent hood on the outside of the building. If not used,
cold air can enter the vent pipe and freeze the heat-
ers heat exchanger when not in use. Such damage
is not covered under the water heater's warranty.
Gas Pressure Switch
Removethe gas pressure switch fromthe bag inthe
carton and the brass 1/4" compression nut fitting which
is meant for theburner manifold tap on the heater, not
the inlet tap on the heater's gas inlet pipe (see p. 3,
FigB). Also remove the four self-tappingscrewsand
the two sections of 1/4" diameter aluminum tubing from
the master carton.
The gas pressure switch must be mounted in such a
waythat the diaphragm is orientedvertically and the
aluminumtubing pieces can easily reach the manifold
pressure test nipple and the burner respectively.
It must not be mounted inside the heater. See
Figure E p.6
When mounting the Gas Pressure Switch: We
recommendmounting thegas pressureswitch vertically
against a wall on the lower left side of the water heater.
See Figure E p.6. Because the cabinet cover is three
sidedwe do not recommend screwingthe gas pressure
switch to the left side of it. Instead, mount the gas
pressure switch vertically against a wall on the lower left
side of the water heater. Installed in this manner all
necessary connections will be within reach and there
willbeminimal interferencewhen servicing.
2
Before beginning installation review
required clearances for Water Heater,
Power Vent Motor and Vent Hood

INSTRUCTIONS (SEE DIAGRAMS ABOVE)
1. Mount gas pressure switch by securing it to
the chosen location with a screw in each one
of the four mounting holes.
2. Use a tube cutter to make a clean cut (not
crimped) at each end of the two lengths of the
1/4" aluminum tubing. One tube must be long
enough to reach from the fitting marked
"connect to gas valve" to the pressure tap port
onthe heater'sburner manifold (Not to the
inlet gas pressure port of the water heater
since there will be constant gas pressure
there). Thetube must be long enoughto enter
thebottom ofthe waterheater frontcover and
attachto theburner manifold without difficulty
(See Figure B). The second tube must be long
enoughtoreach from the gas pressure switch
to the burner area, but not in the pilot flame
area. Allowenough slackfor very gradual
bends.
(See FigureAfor gas pressure switch ports).
3. ATTENTION - Failure to follow the next series
of instructions may result in breaking a part.
a. Removethe brass pressure tap fittingfrom
theburner manifoldof thewater heater. This
fitting will not be required for reuse.
b. Bend one 1/4" aluminum tubing so that it
will run from the gas pressure switch to where
thefitting attaches tothe burner manifold.
Make gradual bends - do not crimp the tube.
c. Do not connect to burner manifold, first
assemble the 1/8" NPT male by 1/4"
compressionfitting with nut and sleeve to
this end of the aluminum tube. Tighten the
fitting and nut with two wrenches.
d. Separate the joint just made in step 3.c.
ROUTE TUBING TO PRESSURE
TAP PORT ON THE
HEATER'SBURNER MANIFOLD
ROUTE TUBING TO BURNER
AREA OR ATMOSPHERIC VENT
PRESSURE TAP-GAUGE PORT
(WHERE HEATER'SBURNER
MANIFOLD PRESSURE CAN BE
MEASURED)
FIGURE A
125BMODEL SHOWN
MANIFOLD TAP
3
FIGURE B

e. Hand thread the pressure tap fitting into
theheater's burner manifold. Usea small
amount of an appropriate threadsealant onthe
male end of the fitting. Over tightening of
the fitting will break it.
f. Guide the end of the tube into the com-
pression fitting. While using one wrench to
hold back the pressure tap fitting, gently snug-
up the compression nut with a second wrench.
4. Bend the second piece of aluminum tubing
(from step 2) so that it will reach from the gas
pressureswitch throughthe underneath of the
heaterto anarea belowthe burners.
Connect one end of the tube to the fitting
marked"warning" on the gaspressure switch.
The other end of the tubing should now
extend to burner area close to pilot,
position it just below the stainless steel
burners. This tube should not discharge into
theflame norshould itextend abovethe upper
edge of the burners. This tube vents gas to the
combustion chamber for ignition in case of a
diaphragmfailure inthe gas pressure switch.
NOTE: The gas pressure switch has a built in
pressure tap marked "gauge port". Use this
tapinstead ofthe heater'smanifold tapwhen
checkingmanifold pressure. (SeeFigureA)
4
Linear Spillage Sensing Switch
Thisswitch provides a means for safety shut down of the
waterheaterin theevent of flueblockage orpower venter
failure. Ifhot fluegasses spill from the drafthooddiverter,
the draft spillage sensing switch will open the pilot safety
circuit and shut off all gas to the water heater. The switch
isnormally closed and opens attemperatures greater
than 185º F. It has a manual reset button.
INSTRUCTIONS
1. Theentire lengthof thecopper capillary
sensing tube is heat sensitive. The idea is to
suspend the tube within close proximity of the
heater'sdrafthooddiverter. Note: do not
cut the copper capillary sensing tube.
2. The linear spill switch should mount in a
location where the tube can extend across the
topof thedraft diverters while allowing the
switch cables toreachthe ECO.
(SeeFigure C,page 5)
3. Route the cables to the ECO switch inside the
water heater keeping the cables out of contact
withhot surfaces.
SAFETYCIRCUIT
The linear spill switch, when wired in series with the
Thermocoupleor PilotFlame Sensorand ECO(s)of the
waterheater,form the Safety Circuit.

1. The ECO is mounted on the lower left
outlet water pipe. (See figure C)
a. Remove one lead connecting to ECO
terminal, it does not matter which one is
disconnected.
b. Attach 1/4" quick connect terminal end of
linear spill switch cable to now exposed
terminal of the ECO.
c. Remove the eyelet ended terminal from
the other spill switch cable. Affix the push on
male spade connector, which is provided with
the AQ1, to this spill switch cable.
d. Connect this male spade connector to the
removed lead wire from step 3.a.
The linear spill switch should be attached to the upper
right-handside on thedraft hooddiverter (see figureD),
onthe Model425HN and125HX the linear spill switch
shouldbe attached to the upperleft-hand side ofthe
drafthood diverter. Therearetwoholes providedfor
attachment on this diverter and only the front most hole
should need to be used. With the provided #12 self
tapping sheet metal screw securely mount the spill
switch bracket to the diverter. For ease of access
position it so the reset button faces outward and then
bend the bracket so the switch can stand vertically.
The copper capillary sensing tube should then be di-
rected to the opposite end of the draft hood diverter, by
layingit infront ofthe 5"diameter ventpipe opening,and
downthe otherside of the drafthood diverter.
DISCONNECT EITHER WIRE FROM ECO
TERMINALS ON HOT WATER PIPE. PUSH ON
ONE SPILL SWITCH LEAD CABLE TO ECO
AND OTHER (RETROFIT FIRST) INTO
EITHER WIRE THAT WAS REMOVED.
ECO
FIGURE C
FIGURE D
CAPILLARY SENSING TUBE
SPILL SWITCH
CABLES
RESET BUTTON
5
NOTE: ON THE MODEL 425HN AND 125HX, REVERSE THE
DIRECTION OF THE CAPILLARY SENSING TUBE SO THE RESET
BUTTON ASSEMBLY IS ATTACHED TO THE UPPER LEFT-HAND SIDE OF
THE DRAFT HOOD DIVERTER.
ECO
HOT WATER PIPE

COMMON SETUP
Mountgas pressure
switch against wall
6
125B Model shown
SeeFigure D, page 5for location ofLinear Spillage Switch
Vent Hood(see freezeprevention
informationonpage 2)
Powerventmotor
4" single wall pipe* (galvanized or
stainless steel) or 4" B-type vent*.
* Single wall vent pipe requires a 6" clearance to
combustibles. B-type vent (double wall) requires a 1"
clearance to combustibles. Use of B-type vent is not
permissible downstream outlet side of the fan motor.
Any additional vent pipe used between the fan motor
and the vent hood must be positive pressure rated with
all seams sealed to prevent leakage. Single wall
galvanized or stainless steel pipe is best.
5" to 4" vent
reducerpipe
FIGURE E

CAUTION
Failure to follow these installation
instructions may violate applicable
national and/or local codes
The vent system must terminate so that proper
clearances are maintained as cited in the National Fuel
GasCode,ANSI Z223.1
"The exit terminals of mechanical vent system shall be
located not less than 7 feet above grade when located
adjacent to a public walkway. The venting system shall
terminate at least 3 feet above any forced air inlet within 10
feet. The venting system shall terminate at least 4 feet
below, 4 feet horizontally from or 1 foot above any door,
window or gravity air inlet into any building."
Also, "The vent terminal shall also not be installed closer
than 3 feet from the inside corner of an L-shaped structure,
or less than 1 foot above grade."
POWER VENT FAN AND MOTOR
Code Requirements
Power vent installation must be in accordance with the
following requirements of the National Fuel Gas Code:
• All portions of the vent system under positive
pressureduringoperation (onthedownstream
outletside of the fan motor)shall use galva-
nized or stainless steel single wall vent pipe
andbe sealedto preventleakage offlue gases.
• Provisions shall be made to interlock the
appliance(s) to prevent the flow of gas to the
main burners when the draft system is not
performing so as to satisfy the operating
requirementsofthe equipmentfor safe
performance.(Linear spillage switch:p.4)
Installation Restrictions
1. Power vent motor should be installed as close
to the termination of the vent system as
possibleto obtainoptimal appliance efficiency
andto prevent fluegas leakage.
2. Power venter must be mounted with motor
shaft horizontal to prevent motor bearing
wear.
3. Power venter housing is single walled. A 6"
clearance from combustible material must be
maintained. (See Figure G)
4. Position the 5" to 4" reducer pipe on top of the
heater first and then connect a 4" 90º elbow
tobegin the horizontal run. Observing this
guidelinewill helpto establish aproper draft.
v
v
6"
v
v
6"
v
v
6"
FIGURE G
FIGURE F
NOTE: FOLLOW REQUIREMENTS IN FIGURES F & G ON THIS PAGE BEFORE
INSTALLING VENT HOOD, THEN USE TEMPLATE ON PAGE 13 TO CUT HOLE.
7

INSTRUCTIONS
(DO NOT BEGIN THESE PROCEDURES
UNTIL VENT HOOD HAS BEEN
INSTALLED)
1. Remove vibration mounts, nuts and washers
from parts bag. Install on power venter as
shown in (Figure H).
2. To prevent vibration, securely support power
venter from ceiling or joist using a plumber's
strap or wire fastened to the vibration mounts.
As an alternative means of support, a wall
bracket may be used to support the underside
of the motor. (NOTE: Plumbers strap, wire or
wall bracket must be supplied by installer.)
3. Connect the power venter outlet to the inner
sleeveof the vent hood. (See page6 forvent
pipingrequirements).Use the4pre-punched
holes in the outlet collar of the power venter as
a guide to drill 1/8" diameter holes into the vent
pipe. Fastenpower venteroutlet to thevent
hoodinlet (or single wall pipe, depending onif
additionalpiping is being used betweenthe
venter and the hood) usingsheet metal screws.
4. Anyvent pipeconnections usedafter thepower
venter(between it andthe venthood) willbe
underpositivepressure during operation. The
vent pipemust begalvanized orstainless steel
single wall vent pipe. The connections must be
sealedwith hightemperature silicone sealant or
aluminumvent pipetape suppliedby the
installer.
5. Install properly sized vent pipe connections
fromthe powerventer inlet to the water heater's
outlet,avoidingelbowswherever possible.
Position the 5" to 4" reducer pipe on top of the
water heater first and then connect a 4" 90º
elbowto beginthe horizontalrun. Observing
this guideline will help to establish a proper
draft. When using anAQ-1 the maximum
horizontaldistance from the water heaterto the
powervent motor is 100 feet.Subtract 10feet
foreachaddedelbow.
6. Support the vent pipe in accordance with vent
manufacturer's instructions. Vent pipe is not
supplied in the power venter package, except
for the 5" to 4" reducer vent pipe in the AQ-1.
Observe the clearances associated with the
class of vent pipe used.
Installation - Electrical
1. Route the control cable from the power venter
fan along the ceiling or joists down to the gas
pressure switch, taking care not to come
closer than 6" to the vent pipe or any other
potentially hot surface. In many cases, the
gas supply piping can be used as a routing
path from the ceiling down to the controls,
using the supplied nylon ties to secure the
cable.
2. Connect the BLUE wire from the jacketed
power vent cable onto the normally open
terminal of the gas pressure switch.
(See Figure I)
FIGURE H
8

3. Connect the RED wire from the jacketed cable
onto the common terminal of the gas pressure
switch. (See Figure I)
NOTE: If the distance between the power
venter and the gas pressure switch is
greater than the length of the cable, splice
a section of 2 conductor, PVC sheathed,
105º C thermostat cable to the supplied
cable. Make sure that the colored leads
remain consistent.
5. Make sure pressure switch is mounted in such
away that the diaphragmis oriented vertically.
Combustion Air Test
1. Closeall doorsand windows of the building.
If the water heater is installed in a utility room
or closet, close the entrance door to this room.
Closefireplacedampers.
2. Turn on any clothes dryers. Turn on all
exhaust fans, such as a range hood, bath
roomexhaust fans and whole housefans, to
maximum speeds. (Do not turn on any fans
used strictly for summer exhausting).
3. Open a hot water tap to full flow.
4. Allowall fansand the water heater tooperate
forfive(5) minutes.
5. Trippingof thespillage switch circuit (resulting
in shut down of the heater) during the 5 minute
operationindicatesan unsafeoperating condi-
tion. Turn off gas supply to water heater and
DONOT OPERATE UNTILUNSAFEVENTING
CONDITIONIS INVESTIGATED BYA
PROFESSIONALCONTRACTORORUTILITY
SERVICEPERSONNEL.
6. Returnall windows,doors andfans to their
previousconditionof use.
FIGURE I
TROUBLE-SHOOTING, MAINTENANCE
AND TEST PROCEDURES
Vent System Maintenance
The vent system must be inspected at regular 3 month
intervals. Points of inspection are as follows:
1. Screened opening of the vent hood should be
free from foreign material and cleaned as
necessary.
2. Check all vent system connections for leak-
age and reseal where needed. If any vent
pipe shows signs of deterioration, replace
immediately and check new connections for
possible leaks. Reseal using RTV Red HiTemp
SiliconeSealeror equivalent.
Inspectproper closureof theback draftflapper
accessory, if used, and correct if it does not
closeproperly afteruse.
Gas Pressure Switch Test
1. Followthe waterheater operating instructions
to light the pilot / operate the heater.
2. Open a hot water outlet. This should energize
the power vent system. Next close the hot
water outlet to de-energize the venter.
3. Repeat step 2 to assure proper operation.
4. If power venter does not energize, check that
the gas pressure switch tubes are properly
connected and that the tube ends are not
pinched closed.
9