Bosch DX Series Manual



Revised 11-11
6720220327





Subject to change without prior notice Revised 11-11
6720220327
DX 035 00 - 1
DX - R410A AIR HANDLER VOLTAGE DESIGNATION
1 = 208-230/1/60
HY - HYDRONIC AIR HANDLER
ELECTRIC HEAT KW
00 - NO ELECTRIC HEAT
05 - 5KW ELECTRIC HEAT
10 - 10KW ELECTRIC HEAT
15 - 15KW ELECTRIC HEAT
20 - 20KW ELECTRIC HEAT
NOMINAL CAPACITY IN
THOUSANDS OF BTUH

 
©Copyright 2011 Bosch, Inc All rights reserved

Model Nomenclature ...........................................................................................2
Physical Data.. ....................................................................................................3
Dimensional Data. ...............................................................................................4
General Information ............................................................................................6
Initial Inspection .................................................................................................6
Moving and Storage ............................................................................................6
Safety Considerations .........................................................................................6
Reference ............................................................................................................6
Location ..............................................................................................................7
Installation/Operation Safety Rules ....................................................................7
Minimum Clearances ..........................................................................................8
Arrangement .......................................................................................................8
Upow Application ..............................................................................................8
Horizontal Application ........................................................................................8
Downow Application .........................................................................................9
Downow Conversion Kit ..................................................................................10
Furnace Installation ..........................................................................................11
Electrical Wiring ................................................................................................11
Line Voltage Wiring ...........................................................................................11
Field Installed Electric Heater Kits ....................................................................12
Variable Speed Motor ........................................................................................13
Replacing ECM Motor .......................................................................................13
ECM Interface Board & Thermostat Connections ..............................................14
Control Wiring ...................................................................................................15
Condensate Drain .............................................................................................16
Duct System ......................................................................................................16
Piping ................................................................................................................17
DX Refrigerant Piping ........................................................................................17
Water Piping .....................................................................................................18
Chilled Water Piping .........................................................................................18
Hot Water Piping ...............................................................................................18
Field Installed TXV .............................................................................................18
Check Test and Start Up ....................................................................................19
System Shut Down ............................................................................................20
Periodic Maintenance .......................................................................................20
Connecting Unit Mounted Controller Water-to-Water Unit to HY Air Handler .....20
Performance Tables ..........................................................................................22
Motor Control Board Settings ...........................................................................23
System Piping Schematics ................................................................................24
Electrical Data ...................................................................................................25
Electrical Diagrams ...........................................................................................26
Unit Check-Out Sheet .......................................................................................31



6720220327
Revised 11-11 Subject to change without prior notice

Table 1: Physical Data
DX UNITS DX025 DX035 DX049 DX061 DX071
Nominal Capacity (Tons) 2 3 4 5 6
Refrigerant Type R410A
Liquid Line Connection Size (in) 3/8 3/8 3/8 3/8 3/8
Suction Line Connection Size (in) 3/4 3/4 7/8 7/8 7/8
Standard Filter Size 16 x 20 x 2 20 x 20 x 2 20 x 24 x 2 20 x 24 x 2 20 x 24 x 2
Condensate Connection Size (in) 3/4 3/4 3/4 3/4 3/4
Blower Size 9X6 10X7 12X9 12X10 12X10
Blower Motor HP 1/3 1/2 3/4 1 1
Blower Motor Type ECM Style - Constant CFM/Variable Speed
Available Electrical (v/p/h) 208-230 / 1 / 60
Shipping Weight (lbs) 120 145 202 212 217
Installation Weight (lbs) 108 132 170 172 180
HY025 HY035 HY049 HY061 HY071
Nominal Capacity (Tons) 2 3 4 5 6
Water In Connection Size (in) 7/8 7/8 1-1/8 1-1/8 1-1/8
Standard Filter Size 16 x 20 x 2 20 x 20 x 2 20 x 24 x 2 20 x 24 x 2 20 x 24 x 2
Condensate Connection Size (in) 3/4 3/4 3/4 3/4 3/4
Blower Size 9X6 10X7 12X9 12X10 12X10
Blower Motor HP 1/3 1/2 3/4 1 1
Blower Motor Type ECM Style - Constant CFM/Variable Speed
Available Electrical (v/p/h) 208-230 / 1 / 60
Shipping Weight (lbs) 130 145 215 215 218
Installation Weight (lbs) 110 132 184 184 184


Subject to change without prior notice Revised 11-11
6720220327
  

               
DX025 17.50 43.00 21.00 15.50 12.50 13.50 11.00 6.75 16.75 14.00 11.00 10.75 2.00 1.50 5.00
DX035 21.00 48.00 21.00 19.00 12.50 14.50 13.00 6.75 20.00 17.00 12.75 10.30 2.30 4.35 5.00
DX049 24.50 58.75 21.75 23.35 21.25 19.75 17.25 6.75 26.00 23.00 16.75 14.35 2.30 4.35 4.50
DX061 24.50 58.75 21.75 23.35 21.25 19.75 17.25 6.75 26.00 23.00 16.75 14.35 2.30 4.35 4.50
DX071 24.50 58.75 21.75 23.35 21.25 19.75 17.25 6.75 26.00 23.00 16.75 14.35 2.30 4.35 4.50




6720220327
Revised 11-11 Subject to change without prior notice

                  
HY025 17.50 43.00 21.00 15.50 12.50 13.50 11.00 6.75 16.75 16.25 13.50 10.75 8.25 4.75 2.00 4.00 8.75 2.00
HY035 21.00 48.00 21.00 19.00 12.50 15.50 13.00 6.75 20.25 19.75 14.25 12.75 10.25 7.50 2.25 4.25 10.50 2.50
HY049 24.50 58.75 21.75 19.50 16.25 19.75 17.25 6.75 28.25 27.75 19.75 16.00 13.50 10.25 2.25 4.25 12.50 2.25
HY061 24.50 58.75 21.75 19.50 16.25 19.75 17.25 6.75 28.25 27.75 19.75 16.00 13.50 10.25 2.25 4.25 12.50 2.25
HY071 24.50 58.75 21.75 19.50 16.25 19.75 17.25 6.75 28.25 27.75 19.75 16.00 13.50 10.25 2.25 4.25 12.50 2.25




Subject to change without prior notice Revised 11-11
6720220327

This single piece air handler provides the exibility
for installation in any upow, downow, or
horizontal application. These versatile models may
be used with or without electric or hot water heat.
The direct drive ECM variable speed motor provides
a selection of air volume to match any application.
The unit can be positioned for bottom return air in
the upow position, top return air in the downow
position and end return air in the horizontal
position.
 Seeeldinstalleddownowconversionkit
installationinstructions.

Be certain to inspect all cartons or crates on each
unit as received at the job site before signing the
freight bill. Verify that all items have been received
and that there are no visible damages; note any
shortages or damages on all copies of the freight
bill. In the event of damage or shortage, remember
that the purchaser is responsible for ling the
necessary claims with the carrier. Concealed
damages not discovered until after removing the
units from the packaging must be reported to the
carrier within 24 hours of receipt.
Installation of accessories or eld conversion
should be accomplished before setting the unit in
place or connection of any wiring, electric heat,
duct, or piping.

If the equipment is not needed for immediate
installation upon its arrival at the job site, it should
be left in its shipping carton and stored in a clean,
dry area. Units must only be stored or moved in the
normal upright position as indicated by the “UP”
arrows on each carton at all times. If unit stacking is
required, no more than stacking 2 units are
permissible.

Installation and servicing of this equipment can be
hazardous due to system pressure and electrical
components. Only trained and qualied personnel
should install, repair, or service the equipment.
Untrained personnel can perform basic functions of
maintenance such as cleaning coils and replacing lters.
Caution
Beforeperformingserviceormaintenance
operationsonthesystem,turnoffmainpowerto
theunit.Electricalshockcouldcausepersonal
injuryordeath.
When working on equipment, always observe
precautions described in the literature, tags, and
labels attached to the unit. Follow all safety codes.
Wear safety glasses and work gloves. Use a
quenching cloth for brazing, and place a re
extinguisher close to the work area. Overheating
of the TXV during brazing will damage the valve
and have adverse effects possibly causing injury or
damage to the unit during operation.

This instruction should be used in conjunction
with instructions supplied with each eld installed
accessory as well as outdoor section. Installer
should pay particular attention to the words;


Caution
Safetyinstructionsinthisdocumentareframedand
identiedbyawarningtrianglewhichisprintedona
greybackground.
Electricalhazardsareidentiedbyalightning
symbolsurroundedbyawarningtriangle.
Signal words indicate the seriousness of the
hazard in terms of the consequences of not
following the safety instructions.
 indicates possible damage to property or
equipment, but where there is no risk of personal
injury.
 indicates possible personal injury.




6720220327
Revised 11-11 Subject to change without prior notice
 indicates possible severe personal injury.
 indicates possible risk to life.

Notescontainimportantinformationincases
wherethereisnoriskofpersonalinjuryormaterial
lossesandareidentiedbythesymbolshownon
theleft.Theyareborderedbyhorizontallines
aboveandbelowthetext.

Locate the unit in an indoor area that allows easy
general maintenance. The following issues should be
considered when locating the air handler:
1. Allow sufcient room for the removal of the lter
and access panels, and has enough room for
service personnel to perform maintenance or
repair. At least 30” clearance on the front side
should be provided.
2. Provide sufcient room to make uid, electrical,
and duct connection(s).
3. If the unit is located in a conned space such as
a closet, provisions must be made for return air
to freely enter the space.
4. On horizontal units, allow adequate room below
the unit for a condensate drain trap and do not
locate the unit above supply piping.
5. When the coil is installed in a draw-thru
application, it is recommended to trap the
primary and secondary drain line. If the
secondary drain is not used, it must be capped.
6. The cabinet will sweat when unit is installed in a
non-conditioned space such as an attic or
garage. Installer must provide protection such as
full size auxiliary drain pan on all units installed
in a non-conditioned space to prevent damage
from condensation runoff. It is also
recommended that the unit be completely
insulated on the exterior with at least 1” thick
berglass insulation with the vapor barrier on
the outside.
These units are not approved for outdoor
installation; therefore, they must be installed inside
the structure being conditioned. Do not locate in
areas that are subject to freezing.
Caution
Ifelectricheatisused,aminimumclearanceof1”
mustbemaintainedonallsidesofthesupplyair
ductand/orplenumcontinuouslyforupto3’.


1. Read these rules and instructions carefully.
Failure to follow these rules and the installation
instructions could cause a malfunction of the unit,
and a possible safety hazard. Keep these
instructions nearby the unit for future reference.
2. While this unit has been designed and
manufactured to comply with National codes, it
is the installer’s responsibility to install this unit
to comply with National codes and/or prevailing
local codes and regulations. BOSCH Group
assumes no responsibility for units installed in
violation of any code or regulation.
3. Before servicing, disconnect all electrical
connections allow unit to cool. Components
may be hot.
Caution
WARNING:ALWAYSSHUTOFFELECTRICITY
WHENWORKINGONUNIT.
Thiswillpreventanyelectricalshocksorburns.
4. Ground the unit to prevent electric shock. All
electrical wiring should be in accordance with
the National Electric Code.
5. Duct work must be installed in accordance with
the standards of the National Fire Protection
Association (NFPA) for the installation of Air
Conditioning, Warm Air Heating and Ventilating
Systems (NFPA 90A and 90B). Duct work in
non-conditioned spaces must be insulated to
prevent formation of condensate and for
maximum efciency.
6. The safety testing agency label appearing on
these units covers the unit and factory installed
coil (if provided) only. It does not cover any
other equipment. Exterior surface of cabinet
may sweat when units is installed in a non-
conditioned space such as an attic or garage.
Installer must provide protection such as full
size auxiliary drain pan on all units installed in a



Subject to change without prior notice Revised 11-11
6720220327
non-conditioned space to prevent damage from
condensation runoff. It is recommended that
units installed in non-conditioned spaces be
insulated with 1” thick berglass with the vapor
barrier on the outside.
7. While designed to operate quietly when
properly installed, several steps should be
taken insure this. Use of isolation pads when
mounting unit, exible duct collars for
discharge, and use of acoustical duct liners are
all good installation practices that promote
quite operation.
8. Cabinet insulation is rated for R-4.2 (standard).
Some jurisdictions require R-6.0 on installations
in a non-conditioned space. Add insulation 1”
thick to exterior of unit to comply in these
jurisdictions, putting the vapor barrier on the
outside.
9. Upon leaving the factory, the refrigerant piping
system is pressurized with nitrogen. Relieve
pressure before opening up the system for pipe
soldering or TXV removal by depressing the
Schrader valve on coil manifold.
Hotwatercanscald.Waterheatedtoa
temperaturewhichwillsatisfyspaceheatingcan
scaldandpermanentlyinjureapersonupon
contact.Somepeoplearemorelikelytobe
permanentlyinjuredbyhotwaterthanothers;
includingtheelderlyandchildren.Checklocal,
State,andNationalcodesrequiringcertain
temperaturewateratthehotwatertap.Special
precautionsmustbeusedinadditiontousingthe
lowestpossibletemperaturesettingthatsatises
yourhotwaterneeds.Atemperingdevicesuch
asamixingvalveshouldbeusedatthehotwater
taps,orwaterheater.

These units have a 0” (zero inch) minimum
clearance to combustible materials rating from all
cabinet surfaces unless electric heat is installed;
then a minimum of 1" clearance all around must be
adhered to. The unit should be installed with
serviceability clearance of 30" from the front of the
unit. The unit can be serviced entirely from the
front, including replacing the lter. Be sure to route
primary and secondary condensate drain piping so
as not to obstruct replacement of lter.

Units are shipped from the factory arranged to be
installed in an upow or horizontal right to left air
ow position. Horizontal right to left means, when
facing the front of the unit, when the unit is laid on
its side, the supply air opening is to the left and the
return opening is to the right. These models are
eld convertible to a horizontal left to right air ow
position.

In an upow installation the discharge outlet is at
the top. Care should be taken to insure unit is level
to permit proper condensate drainage. Normal
upow installation will be in a closet or basement.
If installed in a closet, the closet should have a
platform framed in, with an opening at the top of
the platform centered in the closet. Connect the
supply air outlet to a plenum. Install return air
grilles from outside the closet to space below the
platform. Platform must be at least 12” above the
oor. If installed in a basement, run supply and
return duct work in accordance with local codes.
Install the lter rack provided prior to placing the
air handler on the bottom plenum

Horizontal applications will normally be used in an
attic or crawl space. This type of installation
requires a return air duct be attached to the unit
inlet. The opposite end of the return air duct is
attached to a return air lter grille through the
ceiling or wall. Remove air lter from unit if lter
grille is used. The unit is shipped in right to left
conguration. For left to right applications (before
connecting drains, refrigerant or water piping)
remove coil and doors and move horizontal pan to
right side. Reinstall coil and doors.
Caution
Iftheairhandleristobeinstalledinan
unconditionedspace,ensurethatallrefrigerant
pipingisfullyinsulatedwithatleast½"insulation,
andthatbothsupplyandreturnductsarefully
insulatedwithaminof1"insulation.
  



6720220327
Revised 11-11 Subject to change without prior notice
While horizontal units may be installed on any level
surface strong enough to hold their weight, they are
typically suspended above a ceiling by threaded
rods and a unistrut framing system; however
hanging bracket kits (See Figure 1) are available
from Bosch as an accessory (Part # 930-004 or
930-006). If the hanging bracket kit is purchased
from Bosch, always refer to the hanging bracket
assembly and installation instructions for details.
The all thread rods must be securely anchored to
the ceiling or fastened to the structural member
intended on carrying the load of the air handler.
Horizontal units installed above the ceiling must
conform to all local codes. An auxiliary drain pan if
required by code should be at least four inches
larger than the bottom of the heat pump. Plumbing
connected to the heat pump must not come in
direct contact with joists, trusses, walls, etc.


Some applications require an attic oor installation
of the horizontal unit. In this case the unit should
be set in a full size secondary drain pan on top of a
vibration absorbing mesh. The secondary drain pan
prevents possible condensate overow or water
leakage damage to the ceiling. The secondary drain
pan is usually placed on a plywood base isolated
from the ceiling joists by additional layers of
vibration absorbing mesh. In both cases, a 3/4”
drain connected to this secondary pan should be
run to an eave or at a location that will be
noticeable. If the unit is located in a crawl space,
the bottom of the unit must be at least 4” above
grade to prevent ooding of the electrical parts due
to heavy rains.
The unit is shipped to be installed without
modication in a right to left conguration. See
 for details.
For left to right applications:
1. Remove the unit access panels.
2. Remove the cooling coil.
3. Move the condensate drain pan to the right
side.
4. Reinstall the cooling coil.
5. Connect the condensate drains and refrigerant
lines.
6. Reinstall unit access panels.

Contact the Bosch After Sales Department for
purchasing a proper downow conversion kit.
Caution
Itismandatorytouseanemergencyauxiliary
drainpanwithanycoilorairhandlerinstalledin
anatticoraboveanishedceiling.
You must use the downow conversion kit and
follow the instructions below. Refer to Figures 2
and 3.
1. Remove the blower and control box access
door.
2. Remove evaporator coil access door and
discard it. The evaporator access door will not
be re-used.
3. Remove evaporator coil assembly with drain
pan by sliding out the front of the unit as shown
in Figure 2.
4. Remove 6 screws (3 on each side of unit),
securing evaporator coil support rails. Refer to
Figure 2.
5. Flip the unit so the top is not the bottom.
6. Re-install the evaporator coil support rails in
the holes provided in the unit casing as shown
in Figure 3. Use the six (6) screws that were
removed in step 4 to secure the evaporator coil
support rails to the unit casing.
7. Re-install the cooling coil in the upright position
as shown in Figure 3.
8. Remove the new evaporator coil access door
from the kit and install over the evaporator
section as shown in Figure 3.
 

 
Subject to change without prior notice Revised 11-11
6720220327
  
9. Re-install the blower and control box access
door in the upside down position and secure
with the screws that were removed in Step 1.
Hydronic heat units cannot be used in the down
ow position.


1. Remove evaporator coil door and discard. The
door cannot be used in the downow
conguration. Remove the new evaporator coil
door from the conversion kit box.
2. Remove the evaporator coil assembly with the
drain pan by sliding it out of the front of the unit
as shown in Figure 2.
3. Remove the 6 screws (3 on each side of the unit)
securing the evaporator coil rails. Unit is ready to
be reassembled in the downow conguration.
1. Remove evaporator coil door and discard. The
door cannot be used in the downow
conguration. Remove the new evaporator coil
door from the conversion kit box.
2. Remove the evaporator coil assembly with the
drain pan by sliding it out of the front of the unit
as shown in Figure 2.
3. Remove the 6 screws (3 on each side of the
unit) securing the evaporator coil rails. Unit is
ready to be reassembled in the downow
conguration



1. Invert the air handler 180° and reinstall the coil
support rails, just above the blower. Use the six
(6) screws that were removed in the
disassembly instructions.
2. Slide the evaporator assembly back into the coil
section. Evaporator must be installed so it is
congured in the “A” position.
3. Install the new evaporator coil door that was
removed from the kit.




Caution
CombustibleFloorBaseMUSTBEUSED
whentheunitisbeinginstalledon
combustibleooring.Theunitcannotbe
installedoncarpeting.
Failuretousethecombustibleoorbase
combustibleooringorinstallingtheuniton
carpetingcouldresultinarecausingpersonnel
injury,propertydamageorlossoflife.
Before installing the combustible oor base make
sure that there is a minimum of R-12 insulation
between the sheet metal and any wood or
combustible ooring. Refer to Figure 4 for typical
combustible oor base installation.



6720220327
Revised 11-11 Subject to change without prior notice



Closet Installation
Prior to installing the furnace make sure the holes
are cut into the oor for the refrigerant tubing, the
drain line, the electrical wiring, the thermostat
wiring and the condenser control wiring.
1. Remove the top shipping cover and corner
posts.
2. Remove the bottom shipping cover.
3. Remove the blower and control box access
panel (door).
4. Remove the coil compartment access panel
(door).
5. Place the unit into position using one of the
following choices:
A. If the Combustible Floor Base is used you
slide the unit on to the combustible oor
base until the unit is touching the anges on
the back of the oor base.
B. If the Combustible Floor Base is not used
you slide the unit over the duct opening until
the opening in the unit lines up with the duct
opening in the oor.
6. Secure the unit by one of the two choices:
A. If the Combustible Floor Base is used you
secure the furnace to the oor by drilling two
holes through the furnace base and the oor
base at the right and left front inside corners
of the cabinet. Use two screws to secure the
furnace to the oor.
B. If the Combustible Floor Base is not used
you secure the unit to the oor by drilling
two holes through the furnace base at the
left and right front inside corners of the
cabinet. Use two screws to secure the unit to
the oor.
7. Use caulking, sealers, and/or tape to seal
between the combustible oor base and the
opening on the unit or between the opening on
the unit and the duct in the oor.
8. Connect the electrical supply wires and the
thermostat control wires in the control box.
9. Connect the refrigerant lines to the coil.
10. Re-install the coil compartment access panel
(door) and secure with the screws that were
removed in Step 3.
11. Re-install the blower and control box access
panel (door) and secure with the screws that
were removed in Step 2
12. Turn the power on to the unit by following the
procedure in the Users Information Manual.
13. Set the thermostat to the desired temperature.

Refer to the unit nameplate for specic electrical
data.
Caution
Disconnectpoweratmainfuseorcircuitbreaker
distributionpanelbeforewiringunittoprevent
shockorrehazard.


The unit internal wiring is complete except for the
power supply and the thermostat wires. The use of
cable connectors on incoming power supply wires
to relieve any strain on wiring is recommended.


 
Subject to change without prior notice Revised 11-11
6720220327
Follow the steps below to connect the power
supply wires.

1. Remove the blower and control box access
panel (door).
2. Remove the control box cover.
3. Install the cable connectors on the 7/8" dia
holes on the left side and top right side of the
control box.
4. Strip ½" of the insulation on the end of each wire.
5. Insert the wires through the holes in the casing
and through the cable connectors.
6. Insert the black wire into the L1 screw terminal
on the rst circuit breaker from the top and
tighten the set screw to clamp down on the wire.
7. Insert the white or red wire into the L2 screw
terminal on the rst circuit breaker down from
the top and tighten the set screw to clamp
down on the wire.
8. If you are using a single circuit for a 15kW or
20kW model you will need to install a black
jumper wire from the L1 terminal on circuit
breaker #1 to the L1 terminal on circuit breaker
#2 and a white or red jumper wire from the L2
terminal on circuit breaker #1 to the L2 terminal
on circuit breaker #2.
9. Insert the green wire into the ground lug and
tighten the set screw.


10. You will need to insert the black wire from the
second power supply into the L1 screw terminal
on the second circuit breaker down from the
top and tighten the set screw to clamp down on
the wire.
11. You will need to insert the white or red wire
from the second power supply into the L2
screw terminal on the second circuit breaker
down from the top and tighten the set screw to
clamp down on the wire.
12. You will need to insert both green wires into the
ground lug and tighten the set screw.
13. Tighten the screws on the cable connectors
until the power supply wires are securely
fastened to the connector.
The 15kW and 20kW models may be connected to a
single or dual branch circuit.
Caution
 RefertotheNECNationalElectricalCode(NFPA
70)ortheCanadianElectricalCode,PartI(CSA
C22.1)andlocalcodesforwiringmaterial
requirements.
Field wiring must use copper conductors only.
Tighten all wire connectors. Take care not to
damage heater ceramic insulators on electric heat
models. For correct eld wire size see unit
nameplate and eld wiring table inside electrical
compartment door or on blower housing. Use 75°C
wire in unit wiring compartment.
Field wiring must comply with local and national
electric codes. Power to the unit must be within the
operating voltage range indicated on the unit
nameplate or on the performance data sheet.
Caution
 Seeunitforcompletewiringdiagramlocated
insideelectricalcompartmentdoororonblower
housing.
Caution
Operationofunitonimproperlinevoltageorwith
excessivephaseimbalancewillbehazardousto
theunit,constitutesabuseandmayvoidthe
warranty.
Properly sized fuses or HACR circuit breakers must be
installed for branch circuit protection. See unit
nameplate for maximum fuse or breaker size. The unit
is provided with a concentric knock-out, route power
supply wiring through this opening. Always connect
the ground lead to the grounding lug provided.


This instruction covers the physical installation of
the following electric heat kits on the DX and HY
series models. Refer to Table in back of this manual
for electrical specications.
  



6720220327
Revised 11-11 Subject to change without prior notice
The eld installed electric heat accessories are
used on cooling or heat pump models that were not
purchased with electric heat from the factory. Each
air handler model is approved for use with the eld
installed accessory electric heat kit.

1. Follow the instructions in the USERS INFORMATION
MANUAL to properly shut down the air handler.
2. Remove the block off plate shown in Figure 13
and discard. Retain the screws; they will be
used to secure the electric heater mount plate.
3. Insert electric heat kit into the opening where
the block off plate was removed. Secure the
mounting plate with the screws that were
removed from the block off plate.
4. Connect the six pin male plug on the electric heater
assembly to the six pin female plug mounted on the
side of the low voltage control box divider panel.
5. Remove the wiring diagram from the kit, remove
the paper that covers the adhesive back and
place the electric heat wiring diagram over the
wiring diagram located on the blower housing.
6. Follow the instructions in the USERS INFORMATION
MANUAL to properly start up the air handler.
Topreventdamage,carefullyinserttheelectric
heatingassemblythroughtherectangular
openinginthefrontofthedischargeopeningso
theheatelementsupportrodisseatedintothe
holeonthebacksideofthedischargeopening.
Afterinstallingtheelectricheater,aoneinch
clearancemustbemaintainedonallsidesof
thesupplyairductand/orplenumfora
minimumofthirty-sixinchesfromtheair
handlerdischargeopening.

If the air handler has been installed prior to
installing the electric heaters or if an older unit is
being replaced, the supply power wires must be
checked to make sure the wires are the proper sizes
to handle the current load for the heaters. If the
supply power wire size is incorrect, new wires will
need to be installed. Follow the “Power Supply
Wiring” instructions for proper installation.
 - After the supply
wiring has been connected to the circuit breakers
you must remove the transformer and indoor
blower motor wires from the terminal block and
connect them to load side of circuit breaker #1.

If the air handler was previously installed, nothing
will need to change on the low voltage wiring.

Your DX or HY air handler is equipped with an
electronic commutated motor (ECM) that will
deliver constant air ow over a range of external
static pressure amounts. As your air lter becomes
more restricted through normal use, the torque of
the motor is increased to deliver the same quantity
of air ow. These motors are pre-programmed to
have a zero (0) second delay “ON” delay for use
with electric heat and a 60 second “OFF” delay in
order to blow off remaining water condensate.

1. Turn off all electrical supply circuits to the air
handler at the main service panel.
2. Remove air handler blower door and switch the
air handler circuit breaker(s) to “OFF”
3. Disconnect the power cable and the speed tap
cable that connect to the blower motor.
4. Remove the three screws on the right side and
the two screws on the left side of the blower
mounting plate, then remove the angle bracket.
Refer to Figure 5 below for screw locations

5. Slide the blower out of the blower
compartment and set on the oor.


 
Subject to change without prior notice Revised 11-11
6720220327
In addition to providing a connecting point for
thermostat wiring, the interface board also translates
thermostat inputs into control commands for the
variable speed programmable ECM DC fan motor and
displays an LED indication of operating status. The
thermostat connections and their functions are as
follows:
 Second Stage Compressor Operation
 First Stage Compressor Operation
 Fan Operation
 Reversing Valve (energized in cooling)
 Auxiliary Electric Heat (runs in conjunction
with compressor)
 Emergency Heat (electric heat only)
 Transformer 24 VAC Common (extra
connection)
 Transformer 24 VAC Common (primary
connection)
 Transformer 24 VAC Hot
 Dehumidication Mode
If the unit is being connected to a thermostat with a
malfunction light, this connection is made at the
unit’s malfunction output or relay.
Caution
 Ifthethermostatisprovidedwithamalfunction
lightpoweredoffofthecommon(C)sideofthe
transformer,theunitmustbeprovidedwitha
malfunctionrelay(Boschoption#660-006)to
properlyenergizethelight.Therelaycoilwillbe
wiredacrossthe(ALR)and(C)contactsonthe
unit’sUPMboardandtherelay’snormallyopen
contactsacross(ALR)andthemalfunctionlight
connectiononthethermostat.Ifthethermostatis
providedwithamalfunctionlightpoweredoffof
thehot(R)sideofthetransformer,thenthe
thermostatmalfunctionlightconnectionshouldbe
connecteddirectlytothe(ALR)contactonthe
unit’sUPMboard.
Thisonlyapplieswhentheairhandlerispaired
withaBoschcondensingsection.Other
condensingmanufacturesmayhavedifferenttype
ofconnections.Contactthemanufacturerofthe
condensingsectionforproperconnection
methodswhenutilizingthemalfunctionlight.
6. Loosen the wheel set screw by placing wrench on
the screw head and turning counter clockwise.
Loosen the wheel set screw until the shaft can
spin freely 360° while inside the wheel hub. The
wheel set screw is located on the wheel hub on
the opposite side of the motor.
7. Remove the blower motor from the blower housing
by removing the screws on the sides of the housing
that secure the blower to the housing.
8. Remove the blower motor mount assembly by
loosening the belly band bolt and nut, then,
remove the belly bans and mount legs.
9. Insert the new blower motor into the blower
mounting bracket making sure the mounting
legs are properly placed into the belly band and
the legs are straight. Tighten the belly band
screw and nut until belly band is securely
fastened to the motor.
10. Place the motor into the housing so the mount
leg holes line up with the rivet nuts in the
housing. Place the screw into the mount leg
holes and tighten until the mount legs are
securely fastened to the housing.
11. Center the blower wheel in the housing, turn
the motor shaft so the wheel set screw is
located on the center of the at spot of the
shaft and tighten the set screw.
12. Connect the same two cables that were
removed in step 3.
13. Slide the blower assembly into the blower deck,
replace the angle bracket, insert the screws
through the holes in the angle bracket and
tighten the screws into the holes in the blower
deck and the anges in the casing.
14. Switch the circuit breakers to “ON” and replace
air handler blower door.
15. Turn on all electrical supply circuits to the furnace
at the main service (House Circuit Breaker) panel.
16. Set the thermostat to the desired temperature.


The ECM Interface Board is used to connect the
thermostat wiring and the control wiring from the
remote condensing section or water-to-water unit.
  



6720220327
Revised 11-11 Subject to change without prior notice
To the left of the motor control board are a row of
3 red and 4 green LED’s. These LED’s indicate the
operating status of the unit. They are labeled as
follows:
 Emergency Heat On
 Emergency Heat On
 Auxiliary Heat On
 Reversing Valve Energized, unit is in
cooling mode
 Second Stage Compressor On
 First Stage Compressor On
 Fan On
Towards the center of the motor control board is a
single red LED labeled CFM that will blink
intermittently when the unit is running and may
icker when the unit is off. This LED indicates the
air delivery of the blower at any given time. Each
blink of the LED represent 100 CFM of air delivery
so if the LED blinks 12 times, pauses, blinks 12
times, etc. the blower is delivering 1200 CFM.
Refer to the Blower Performance Table in the
Technical Data section at the end of this manual
for factory programmed air delivery settings for
the DX and HY Series.
On the bottom right is a green LED labeled
“DEHUMIDIFY”. The dehumidify function will slow
the speed of the fan by 30% to increase the latent
capacity of the unit. In order to enable this
function, cut the resistor just below the green LED.
This operation cannot be reversed. Once you have
enabled the dehumidication function, this will be
a permanent setting.
On the right side of the motor control board are
four sets of jumper pins labeled ADJUST, PROFILE,
HEAT and COOL. The ADJUST set of pins are
labeled NORM, (+), (-) and TEST. All DX and HY
units will all be set on the NORM position from the
factory, however, airow can be increased (+) or
decreased (-) by 15% from the pre-programmed
setting by relocating the jumper in this section.
The TEST position is used to verify proper motor
operation. If a motor problem is suspected, move
the ADJUST jumper to the TEST position and
energize “G” on the thermostat connection block.
If the motor ramps up to 100% power, then the
motor itself is functioning normally. Always
remember to replace the jumper to NORM, (+) or
(-) after testing and reset the unit thermostat to
restore normal operation.
Caution
DonotsettheADJjumpertothe(-)setting
whenelectricheatersareinstalled.Doingso
maycausetheheaterstocycleontheirthermal
overloadswitches,potentiallyshorteningthe
lifeoftheswitches.
The other three sets of jumper pins are used to
select the proper program in the ECM motor for the
unit. Refer to the Blower Performance Table in the
Technical Data section at the end of this manual for
the proper jumper placement.
Caution
Alwaysdisconnectpowerbeforechanging
jumperpositionsontheinterfaceboard.
To the left of the red and green status LED’s is a row
of 1/4" male quick connects. These are used to
connect the thermostat connections and to pass
thermostat inputs on to the rest of the control circuit
in the condensing section. Remember to always turn
off unit power at the circuit breaker before attaching
or disconnecting any wiring from these connections
to avoid accidental short circuits that can damage
unit control components. Thermostat input cable is
routed through the concentric knockout on the right
side of the cabinet, into the control box. The
thermostat wires are connected to the pig tail leads
in the control box with eld supplied wire nuts.

Field connections to the low voltage leads are made
using appropriate eld supplied wiring connectors.
Consult installation instructions provided with
accessory items for specic information on control
wiring. Use 18 AWG minimum copper conductors for
control wiring up to 50’ between units. 16 AWG control
conductors are recommended for lengths between 50’
and 100’. Class 2 wiring is acceptable. Take care not to
short control leads, transformer burnout could result.
Some manufacturer’s outdoor units are equipped with
a 24 volt control transformer. If this type of outdoor


 
Subject to change without prior notice Revised 11-11
6720220327
unit is used with this air handler, use a thermostat with
isolating contacts to prevent inter-connection of two
separate Class 2 circuits (RC terminal is used for the
condensing section unit and RH terminal is used for the
air handler. The jumper between RC and RH must be
removed). Set thermostat heat anticipator at 0.15
amps for units 12KW or smaller, set at .30 amps for 15
KW and larger.
The labeled terminal block in the remote
condensing section or water-to-water unit will
identify the required connections.

The air handler “A” coil drain pan has two ¾” NPT
female primary and two secondary connections (left
or right hand). Horizontal pan has two ¾” NPT female,
one primary and one secondary. Piping from each
tting used is to have 1-1/2 minimum trap and each
run in such a manner as to provide enough slope for
adequate drainage to a visible area. A drain line must
be connected to the heat pump and pitched away
from the unit a minimum of 1/8” per foot to allow the
condensate to ow away from the unit.
This connection must be in conformance with local
plumbing codes. A trap must be installed in the
condensate line to insure free condensate ow.
(Heat Pumps are not internally trapped). A vertical
air vent is sometimes required to avoid air pockets.
(See Figure 6). The length of the trap depends on
the amount of positive or negative pressure on the
drain pan. A second trap must not be included.
The horizontal unit should be pitched
approximately 1/4” towards the drain in both
directions, to facilitate condensate removal. (See
Figure 7)

ELEVATION LINE
WHEN MOUNTED LEVEL
1/4″


A supply air outlet collar is provided on all units to
facilitate duct connections. Refer to the
dimensional sheet at the beginning of this manual
for physical dimensions of the collar.
A exible connector is recommended for supply air
duct connections on metal duct systems. All metal
ducting should be insulated with a minimum of one
inch duct insulation to avoid heat loss or gain and
prevent condensate forming during the cooling
operation. Applications utilizing uninsulated duct
work are not recommended as the unit’s performance
will be adversely affected. Do not connect discharge
ducts directly to the blower outlet. The factory
provided air lter must be removed when using a lter
back return air grill. The factory lter should be left in
place on a free return system.
If the unit will be installed in a new installation
which includes new duct work, the installation
should be designed using current ASHRAE
procedures for duct sizing. If the unit is to be
connected to existing ductwork, a check should be
made to assure that the duct system has the
capacity to handle the air required for the unit
application. If the duct system is too small, larger
ductwork should be installed. Check for existing
leaks and repair.
The duct system and all diffusers should be sized to
handle the designed air ow quietly. To maximize sound
attenuation of the unit blower, the supply and return air
plenums should be insulated. There should be no direct
straight air path thru the return air grille into the heat
pump. The return air inlet to the heat pump must have at
least one 90 degree turn away from the space return air
grille. If air noise or excessive air ow are a problem, the




6720220327
Revised 11-11 Subject to change without prior notice
blower speed can be changed to a lower speed to reduce
air ow. (Refer to ECM motor interface board section in
this manual and the Blower Performance Table in the
Technical Data section at the end of this manual.)

Supply and return piping must be as large as the
unit connections on the heat pump (larger on long
runs). Never use exible hoses of a smaller inside
diameter than that of the uid connections on the
unit. Bosch condensing section units are supplied
with either a copper or optional cupro-nickel
condenser. Copper is adequate for ground water
that is not high in mineral content. Should your well
driller express concern regarding the quality of the
well water available or should any known hazards
exist in your area, we recommend proper testing to
assure the well water quality is suitable for use with
water source equipment. In conditions anticipating
moderate scale formation or in brackish water a
cupro-nickel heat exchanger is recommended.
Both the supply and discharge water lines will sweat if
subjected to low water temperature. These lines should
be insulated to prevent damage from condensation.
All manual ow valves used in the system must be ball
valves. Globe and gate valves must not be used due to
high pressure drop and poor throttling characteristics.
Never exceed the recommended water ow rates as
serious damage or erosion of the water to refrigerant
heat exchanger could occur. Refer to the Technical
Data section at the end of this manual to determine the
recommended water ow rate for specic conditions.
Always check carefully for water leaks and repair
appropriately. Units are equipped with female pipe
thread ttings. Consult the specication sheets of
the paired condensing section for sizes. Teon tape
sealer should be used when connecting water
piping connections to the units to insure against
leaks and possible heat exchanger fouling. Do not
over-tighten the connections. Flexible hoses should
be used between the unit and the rigid system to
avoid possible vibration. Ball valves should be
installed in the supply and return lines for unit
isolation and unit water ow balancing.

Air handlers with DX type evaporator coils require
liquid and suction piping sized in accordance with
condensing unit manufacturer’s recommendations.
The evaporator coils have sweat copper connections.
Refrigerant lines should be soldered with silver solder
or other high temperature brazing alloy.
The suction line must be insulated for satisfactory
operation to avoid creating condensation. If the
condensing unit is located over the evaporator coil,
then oil traps are required at equal intervals along the
suction line.
Horizontal suction line runs should be sloped 1" every
20' towards the condensing unit. The manufacturer
recommends that dry nitrogen be owed through the
refrigerant lines during the soldering operation.
Liquid line is capped.
• Install 1 oil trap for a height difference of 15 ft to
25 ft (4.6 m to 7.6 m) between condensing
section and air handler.
• Install 2 oil traps for a height difference of 26 ft to
50 ft (7.9 m to 15.2 m) between condensing
section and air handler.
• Install 3 oil traps for a height difference of 51 ft to
100 ft (15.5 m to 30.5 m) between condensing
section and air handler.
It is not recommended that a height difference of
more than 100 ft exists between the two units.



 
Subject to change without prior notice Revised 11-11
6720220327
Caution
Pressuredropinliquidmustnotexceed30psi
orerraticoperationandthermostaticexpan-
siondamagewilloccur.

All piping must be supported independent of coils
to prevent vibration and stress on coil headers.
Swing joints or exible ttings must be provided to
absorb expansion and contraction strains. Rig id
piping reduces the effectiveness of vibration
isolators. Water piping should always be connected
so that the entering water is on the bottom
connection of the water coil. Coils must be
adequately vented in order to prevent air binding.
Units are provided with manual air vents mounted
through the manifold panel.

Supply and return chilled water piping to the coil
should be ¾ inch ID up to 42,000 BTUs, 1 inch on
units greater than 42,000 BTUs. Water piping must
always be connected so that the entering water is
on the leaving side of the coil.

If a residential water heater is used for space
heating water, do not exceed a distance of 70 feet
between the air handler and the water heater. The
water heater should be the quick recovery type. Air
handler and water heater must be located indoors
and not subject to freezing temperatures.
Caution
Airhandlermustbelocatedsothatifany
connectionsshouldleak,waterwillnotcause
damagetotheadjacentarea.Whensuch
locationscan’tbeavoided,asuitabledrain
panshouldbeinstalledundertheairhandler,
notover1-1/2”deep,withminimumlengthand
widthatleast2”greaterthantheairhandler
dimensionsandconnectedtoanadequate
drain.Undernocircumstancesisthemanu-
facturertobeheldlibelforanywaterdamage
inconnectionwiththisairhandler.
Total piping should not exceed 140 feet. All piping
should be ¾" ID (7/8" OD) copper. CPVC piping
may be used in applications where the water
temperature does not exceed 150°F. It is
recommended that the water shut-off valve for the
water heater be located close to the water heater.
Isolation valves are also recommended.
It is recommended that any devices installed,
which could create a closed system, have a by-
pass and/or the system have an expansion tank to
relieve the pressure built up by thermal expansion
in the water system.
Caution
Toxicchemicalssuchasusedfortreatmentof
boilersornon-potablewaterheatingappli-
ancesshallneverbeintroducedintoapotable
waterspaceheatingsystem.
Caution
Whenthesystemrequiredwaterattempera-
tureshigherthanrequiredforotheruses,a
meanssuchasamixingvalveshallbe
installedtotemperthewaterforthoseusesin
ordertoreducethescaldhazardpotential.
After piping has been installed, allow the system
to ll with water and check connections for leaks.
To insure complete lling of the system, follow
start-up procedure.

Thermal expansion valve (TXV) can be used on
both heat pump and air conditioning applications.
All TXVs have a built in check valve making them
heat pump capable. All are externally equalized
with non-adjustable superheat and are available
with 15% bleed construction. Hard start capability
for outdoor units is not normally required when
15% bleed valve is used. The external equalizer
line attached to the TXV has a female are nut with
built in Schrader valve depressor that attaches to
the Schrader valve port provided on coils.
Caution
Withreferencetothegure9,theTXV
assemblyistobeinstalledbetweenthe
owratordistributorandtheexistingliquidline
attachedtotheowratordistributor.




6720220327
Revised 11-11 Subject to change without prior notice

1. After coil pressure has been relieved, turn the
female swivel nut counter-clockwise to remove.
2. Remove the piston from the owrator
distributor tting using a small diameter wire or
paper clip. (ALWAYS REMOVE PISTON FROM
DISTRIBUTOR BODY WHEN TXV IS INSTALLED).
3. Attach the TXV by connecting the female swivel
nut on TXV outlet to the owrator distributor
(aligning Teon seal rst) and torque swivel nut
to 10-30 ft. lbs.
4. Attach liquid line with female swivel nut to male
rotalock tting on TXV inlet (Aligning Teon seal
rst) and torque swivel nut to 10-30 ft. lbs.
Remove the cap on Schrader valve port on coil
manifold. Attach equalizer tubing with 1/4"
female are nut that include depressor to this
male Schrader port. Torque nut to 10-30 ft. lb.
5. Install the TXV bulb to the suction manifold of
coil or the suction line using the two bulb
clamps furnished with kit.
A. Bulb should be installed on a horizontal run
of the manifold if possible. On lines less than
7/8" OD the bulb may be installed on top of
the line. With 7/8" OD and over, the bulb
should be installed in a position at about 4
or 8 o’clock.
B. If bulb installation is made on a vertical run,
the bulb should be located at least 6 inches
from any bend, and on the tubing side
opposite the plane of the bend. On vertical
bulb installations, the bulb should be
positioned with the bulb capillary tube at
the top.
C. The bulb should be insulated using thermal
insulation to protect it from the effect of the
surrounding ambient temperature.
6. After completing installation of TXV (including
equalizer tube), it will be necessary to leak
check the coil and evacuate the coil through the
service access ttings of liquid and suction line
valves.



The unit should be tested after the system has been
completely installed to determine proper operation.
Unit is equipped with heater time delay controls. All
heating elements should turn on within one minute.
Caution
 Circuitbreakersareequippedwithavisual
“visi-trip”redagindicator.Ifredindicatorshows
thatcircuitbreakerhastripped,thisindicatedthat
aproblemexistsinyoursystemwhichshouldbe
correctedbeforeresettingbreaker.

Caution
 Heatingsystemshouldnotbeswitchedonuntil
systemislledandalltheairinthehotwatercoil
hasbeenvented.
1. Fill and pressurize the water heater and air
handler.
2. The water heater should be started.


 
Subject to change without prior notice Revised 11-11
6720220327
3. Vent air from the water tank by opening a hot
water spigot.
4. Vent and ush the supply and return lines by
attaching a hose to the volume purge valve and
running purge water to a safe location. Run
approximately 5 gallons of water at a high ow
rate to purge.
5. Energize the unit by switching on the line voltage
source and the thermostat. The fan and pump
should start simultaneously. The water coil
should become warm after a few minutes of
operation.
6. Units are rated at temperatures up to 180°F. Set
water source temperature at design temperature
and take proper safeguards for water usage at
supply points as per local codes and safety
considerations.
 Heatpumpcondensingsectionsarenotcableof
producing180°Fwater.Thismustcomefroma
boilersource.ContactBoschforratingsand
capacitiesforboilersystemuse.

For short periods of time during freezing
temperatures if the system is to be left unused, to
prevent freezing of the air handler and piping, do the
following:
1. Do not turn the system off; leave the thermostat
to the air handler left on the heat setting to
maintain a space temperature above freezing
conditions.
2. If the water heater and/or air handler must be
shut down for extended periods, a qualied
service technician should insure that the air
handler and coil are completely drained of water.

The lter must be changed monthly to permit proper
airow for safe and efcient operation. All other
maintenance should be performed by a licensed
technician.





In order to allow your room thermostat or DDC
controller to control the operation mode (cooling
or heating) that your water-to-water unit is
running, you will need to purchase the DY AUTO
CHANGEOVER CONTROLLER
(Bosch Part #:7 738 000 397).
Caution
 ThisaccessoryisonlyneededforaHYair
handlerwithapairedwater-to-waterunitwitha
unitmountedcontroller.Ifyourwater-to-water
unitisremotecontrolled,itisalreadysetupto
functioncorrectlywithanHYairhandler.
This controller will convert an AC signal from the
thermostat or DDC controller when a call for
cooling or heating is made based upon the set
point to a resistance value that the unit mounted
controller will interpret as a water temperature.
This will cause the water-to-water unit to go into
cooling or heating mode as dictated by the
thermostat or DDC controller call.
Connect the “S2” connections on the back of the
water-to-water unit mounted controller to the “S2”
connections on the Auto Changeover Controller. If
a thermostat will be used to control the air
handler, then route a wire from the “O” connection
and from the “C” connection from the back of the
