Airxcel Aqua-Hot 600 Series User manual

Installation Manual
600Series
AHE-600-D04
with

Introduction
©Aqua-Hot® 600D Installation Manual p. 1
Caution Notes
As you read this information, take particular note of the NOTICE,
CAUTION, WARNING and DANGER symbols when they appear.
This information is important for safe and effi cient use of the
Aqua-Hot system.
NOTICE signals a situation where potential damage to the
Aqua-Hot could occur.
CAUTION signals a situation where potential harm or risk
of minor or moderate injury could occur if you do not follow
instructions.
WARNING signals a hazardous situation where potential harm,
risk of serious injury, or death could result if instructions are
not followed.
DANGER signals a situation where immediate risk of serious
injury or death will result if instructions are not followed.
NOTE: This manual will also use notes sections similar to
this one to draw attention to features and practices which
should be observed.
Contents
Caution Notes ...............................................................................1
Introduction ..................................................................................2
System Features ..........................................................................4
Component Cut-Aways .................................................................5
Installing the Aqua-Hot ................................................................7
Support & Clearances ..................................................................8
Installation of the Expansion Tank ..............................................9
Exhaust System ..........................................................................10
Installing the Heat Exchangers ................................................ 13
Mounting the Heat Exchangers .................................................15
Wiring the Heat Exchangers ......................................................16
Plumbing the Heating Loop .......................................................17
Heat Exchangers Layout ............................................................19
Engine Preheat .......................................................................... 20
Diesel Fuel System .................................................................... 22
Domestic Water System Requirements ................................... 25
Plumbing the Domestic Water System .................................... 26
Thermostats ...............................................................................27
Interior Switch Panel ................................................................. 28
Wiring the Aqua-Hot .................................................................. 30
Aqua-Hot Reporter..................................................................... 33
Reporter Manual Mode ..............................................................37
Connecting the 600D to 12V DC Power .................................. 38
Connecting the 600D to AC Power ........................................... 39
Filling the Aqua-Hot ................................................................... 40
Purging the Interior Heating Loop .............................................41
First Operation ........................................................................... 42
Winterizing ................................................................................. 43
Operational Flow Chart ............................................................. 44
Wire Sizing ................................................................................. 45
Appendix A: System Schematics .............................................. 46
Appendix B: Antifreeze .............................................................. 52
Appendix C: Parts & Accessories ............................................. 55
Warranty .....................................................................................61

Introduction
©Aqua-Hot® 600D Installation Manual p. 2
Safety Features
Low-Voltage Shutdown
The Aqua-Hot Reporter is designed to operate between 11V
DC and 16V DC. If the Reporter detects that it is receiving
voltage below 11.8V DC, it will display a low-voltage fault. If
the Reporter system drops below 11.2V DC for more than
30 seconds, a safety mechanism will activate, shutting
down the Aqua-Hot.
Over-Current
An Over-Current fault condition occurs when too much
current is drawn by a component, usually a fan or pump.
When this fault is triggered, the output channel is shut off
until the system has been reset or power-cycled.
Over-Temperature
An over-temperature fault will occur if your Aqua-Hot heating
system has reached 218°F. The Reporter will deactivate
the heater and display an over-temperature fault on the
display screen.
Low-Level Cutoff
If the system senses low fl uid levels, the heating system will
shut down all fans, heat sources, and pumps until the unit
is adequately refi lled.
Reporter “Heartbeat Function”
The Reporter unit with fi rmware 1v5 and later and all
Reporter 2.0 units are equipped with a “heartbeat”
function that establishes a signal between the RV-C system
and the Reporter. The Reporter constantly awaits for a
signal from the RV-C network indicating to the Reporter that
it is to continue normal operation. Loss of 6 consecutive
signals from the RV-C network will trigger the Reporter to
deactivate the Aqua-Hot. Once power is restored to the
coach and the Reporter, “BATTERY DISCONNECT SWITCH
OFF” will be displayed in the fault log, indicating that the
Reporter lost connectivity with the RV-C network.
Manual Mode
The 2.0 Reporters with CFG 1.9 and greater come with a
manual mode in case the general coach RV-C network fails.
It will allow for limited operation while the larger network/
module problem is addressed.
Interlock Switch
The Aqua-Hot 600D is equipped with an interlock switch
that prevents the heater from operating when the cover is
not installed in the correct position or if it is not properly
secured in place. This is a safety device to ensure the
burner will not ignite if the service panel is not properly
secured.
Read all instructions before installing the Aqua-Hot unit. Aqua-
Hot Heating Systems is not liable for damage resulting from
failing to follow instructions contained in this, and any other
Aqua-Hot documentation relevant to this unit.
• Read this manual before installing or using the Aqua-Hot
System to reduce the risk of injury to persons or damage to
the equipment.
• The product identity label contains specifi cations of the
unit, to what standards it has been tested, and important
safety notices.
• Disconnect electric wiring to the Aqua-Hot System before
welding or plasma cutting the coach to avoid damage to
equipment.
• The Aqua-Hot tank and heating loop operate at 0.0 PSI
(zero pressure system). Air pressure to the tank must not
exceed 20 PSI. Exceeding this rating will cause internal
damage to the Aqua-Hot.
• Use caution when working on or near any propane/diesel
fuel system.
• DO NOT connect the 12-volt DC power to the Aqua-Hot if the
vehicle requires welding.
• At maximum operating temperature, the coolant will be
very hot and scalding. Hot vapor or coolant may cause in
serious burns or injury. Be aware of hot surfaces.
• Installation and repairs may only be carried out by an
authorized, factory-trained Aqua-Hot technician. The
heating system must be installed in accordance with local
codes, or in accordance with the Standard for Recreational
Vehicles, (RVIA) ANSI A 119.2/NFPA 501C, NFPA 1192.
• Aqua-Hot will not be liable for problems or damage caused
by the system being installed by untrained personnel.
As with any appliance, allow the Aqua-Hot to completely shut
down BEFORE disengaging the coach 12V power disconnect.
NOTE: For networked control of the Reporter, Aqua-
Hot requires system integrators ensure that individual
commands are received and processed. Aqua-Hot requires
that commands be repeated or confi rmed so that if a
single message were dropped, or if there is a brief network
disturbance, the Reporter would get into the correct state as
soon as the disruption was removed.
The Aqua-Hot Reporter monitors the heating system and
handles all logic relating to safeties and heating control.
As such, the system integrator is required to display all
pertinent status information but not use that information to
lock out operation or add additional safety layers that could
impact the end of operation if a message from the Reporter
was missed.

Introduction
©Aqua-Hot® 600D Installation Manual p. 3
System Overview
The Aqua-Hot 600D is a Hydronic (water-based) Heating
System, a tank-less hot water system, and a diesel engine
preheating system.
The heating system provides moist, quiet, comfortable,
interior heat with up to 5 separate, thermostatically-controlled
temperature zones, and prevents tank and line freezing in the
bays.
The tank-less hot water system produces 90 gallons per
hour of continuous, on-demand hot water.
The diesel engine preheating system circulates the engine’s
antifreeze solution through an internal heating loop in the Aqua-
Hot and pumps it back through the engine, raising the engine’s
temperature from 30°F to 90°F in about 1 hour.
The same heating loop that preheats the diesel engine
allows the Aqua-Hot system to take surplus heat generated by
the motor home’s diesel engine while running, and use it to
heat the Aqua-Hot system.
This TribridHot™ designated system uses one or a
combination of heat sources to heat FDA-Approved Generally
Recognized As Safe (“GRAS”) Propylene Glycol-based antifreeze
solution in the Aqua-Hot’s boiler tank.
The 600D has multiple heating sources: the motor home’s
engine’s surplus heat (while driving), two 120V AC - 2000W
Electric Elements (when plugged into shore power), and a 12V
DC powered diesel burner (when dry camping). These heat
sources can be used separately or simultaneously.
New Low Emissions Technology virtually
eliminates smoke and odor from the exhaust
by reducing total hydrocarbon emission by
82%, making Aqua-Hot the cleanest burning diesel-powered
hydronic heating system available.
Should additional assistance be needed, please contact the
Technical Support at 574-AIR-XCEL (574-247-9235), Monday
through Friday, between 7:00am and 4:00pm MST.
If the information in this manual is not followed
exactly, a fi re or explosion may result, causing
property damage, personal injury or death.
Important Notes:
• A qualifi ed installer or service technician must perform
equipment installation or service. Contact Aqua-Hot for
Factory Authorized Service Centers or Certifi ed Technicians
located near you at www.aquahot.com/service-help, or call
us at 574-AIR-XCEL (574-247-9235).
• Warranty work must be performed by an Aqua-Hot
Authorized Service Center.
• Your on-product identity label contains the specifi cations of
your unit. Factory settings may be adjusted by the vehicle
manufacturer, confi rm fi nal setting with your dealer.
• This heating system has been certifi ed for installation only
in recreational vehicles, not certifi ed for use in boats.
• The Aqua-Hot heating system operates independently of
the vehicle engine and is connected directly to the electrical
system and fuel system of the vehicle.
• Please read this manual and follow instructions to avoid
injuries during installation and/or operation.
Hot Water System
When hot water is requested, domestic water from the
coach’s fresh water tank is transported through a copper coil
in the Aqua-Hot’s boiler tank where heat is transferred from
the heated antifreeze and distilled water solution. The heated
domestic water then fl ows through the tempering valve to be
mixed with cool water from the fresh water tank to achieve an
appropriate temperature before it fl ows to the faucet.
Figure 1

System Features
©Aqua-Hot® 600D Installation Manual p. 4
System Specifi cations
Diesel Burner
Heat Input (Firing Rate) ....................................... 56,000 BTU/hr
Fuel Consumption ....................................................... 0.41 gal/hr
Electric Element
Power Consumption ....................................................(2) 2000 W
Voltage ............................................................. 120V AC / 12V DC
DC Power
Consumption ...................................................184 W (maximum)
Zone Heat Circulation
Pumps ...........................................................................................3
Power Consumption (max) .........................................21 W (each)
Voltage ............................................................................... 12V DC
Heating Zones
Maximum ............................................. 5 (max) + Engine Preheat
Domestic Water Heating
Maximum .....................................................2.0 GPM On-demand
Physical Specifi cations
Dimensions (US)............................18.5” H x 18.5” W x 36.75” L
Dry Weight ......................................................................... 186lbs.
Wet Weight ......................................................................... 303lbs.
All vehicle installations must comply with the requirements listed in
the Recreational Vehicle Industry Association’s (RVIA) ANSI/NFPA
1192 Handbook for Recreational Vehicle Standards. To receive a
copy of this handbook and other Pertinent RVIA Standards, write to:
Recreation Vehicle Industry Association, 1896 Preston White Drive,
PO Box 2999, Reston, VA 22090-0999. Call them at (703) 620-
6003 or visit online at www.rvia.org.
NOTE: This product label is attached to the top of the Aqua-
Hot, and provides a ready reference to specifi cations, test
standards, and important safety notices.
Figure 2
Figure 3

Component Cut-Aways
©Aqua-Hot® 600D Installation Manual p. 5
1
Figure 6
Figure 4
NOTE: The top and side panels have been made transparent in the
view above to aid in the explanation of the heater. DO NOT remove
these panels. Doing so risks irreparable damage to the Aqua-Hot.
Only remove the service panels.
1. Aqua-Hot Reporter
2. Interlock Switch
3. Zone 1 Circulation Pump
4. Zone 3 Circulation Pump
5. Zone 2 Circulation Pump
6. Engine Preheat Pump
7. Diesel Burner
8. Fluid Drain Valve
9. Diesel Burner Controller
10. Domestic Water/
Thermostat
Access Panel
11. Domestic Water Assembly
12. Heating Zone 1 Outlet
13. Heating Zone 2 Outlet
14. Heating Zone 3 Outlet
15. Engine Preheat Outlet
16. Engine Preheat Inlet
17. Air Release Valve
18. Access Cover
19. Domestic Hot Water
Outlet
20. Domestic Cold Water
Inlet
21. Heating Zone 1 Inlet
22. Heating Zone 2 Inlet
23. Heating Zone 3 Inlet
24. Tempering Valve
25. Pressure Relief Valve
26. AC Terminal Blocks
27. Heating Solution Tank
16
13
12 14 15 17
3
2
Figure 5
5
4
6
78910 11
Figure 7
21 22 23
24
19 20
25 26 27
18

Component Cut-Aways
©Aqua-Hot® 600D Installation Manual p. 6
Air Release Valve
Expansion Tank
Connection
Product ID Label
The Aqua-Hot tank and heating loop operate
at 0.0 PSI (zero pressure system). Air pressure
applied to the tank MUST NOT exceed 20 PSI.
Excess pressure will result in internal damage.
Figure 9
Diesel Fuel Inlet &
Outlet Ports
Zone 1, 2, & 3
Inlet Ports
AC Wiring Ports
Zone 1, 2, & 3
Outlet Ports
Wiring Harness Port
Domestic Cold
Water Inlet
Domestic Hot
Water Outlet
Engine Preheat
Inlet/Outlet Ports
Figure 8

Support and Clearance
©Aqua-Hot® 600D Installation Manual p. 7
Installing the Mounting Tray & Aqua-Hot
Install the Aqua-Hot in a compartment that is completely
closed off from living quarters and is accessible only from the
exterior of the coach.
1. Reference the following illustrations below for mounting
information.
2. Cut out the required mounting tray as shown in Figure 10.
3. Install the mounting tray fl ange into the cut out opening.
Reference Figure 11.
4. Insert a #10 machine screw into each of the embossed
holes in the mounting tray (6 total), and tighten to secure
the mounting tray to the coach.
NOTE: Inspect the area near the mounting location to
ensure that no structural members will interfere with
the cut-out for the mounting tray.
Figure 10
NOTE: The Aqua-Hot must be
supported by structural cross-
members that can support at least
185lbs.
5. Secure the mounting tray into place prior to installing the
Aqua-Hot.
6. Place the Aqua-Hot securely into the mounting tray to
ensure that the unit does not move or shift under normal
operating conditions. Reference Figure 12.
Figure 12
Figure 13
NOTE: Remove the bolt securing the front of
the access cover to the mounting tray. This
bolt will need to be reinstalled once the total
installation procedure is complete.
Figure 11

Support and Clearance
©Aqua-Hot® 600D Installation Manual p. 8
All measurements
are in inches
Side View
Front View
Bottom View
Top View

Fluid Expansion Bottle
©Aqua-Hot® 600D Installation Manual p. 9
Installation of the Expansion Tank
Introduction:
The fl uid expansion tank is integral to the operation of the
Aqua-Hot. It provides an area for hot, expanded fl uid to empty
into, and also protects the Aqua-Hot from low-fl uid, which could
lead to catastrophic damage of the Aqua-Hot.
Follow the directions in this section to correctly install the
fl uid expansion tank.
Installation Procedure:
1. Mount the expansion tank as illustrated in Figure 15. The
overfl ow tube should have an incline.
2. Connect and clamp the overfl ow tube from the expansion
tank to the Aqua-Hot’s expansion tank connection as
shown in Figure 15.
3. Drill a hole in the bay fl oor and connect a long enough piece
of overfl ow tubing so that it can be connected to the top
of the expansion tank and extend through the bay fl oor.
Secure tubing with clamps.
NOTE: Avoid any bends or dips in the overfl ow tubing from
the Aqua-Hot. Air can become trapped in these bends and
will prevent excess antifreeze and water heating solution
from depositing properly in the expansion tank.
Hot Fluid Line
Cold Fluid Line
Fill Cap
Lower Fitting
Upper Fitting
Figure 14
Figure 15
Overfl ow Tube
Expansion Tank
Pressure Relief Valve
Expansion hose. Must
vent to the exterior of
the vehicle
Fluid Expansion Tank
Hole in the coach bay
fl oor for overfl ow hose
Tension Clamp
Tension Clamp
NOTE: The top of the expansion tank must be mounted
higher than the highest point on the Aqua-Hot.
Tension Clamp

Fluid Expansion Bottle
©Aqua-Hot® 600D Installation Manual p. 10
Exhaust System Requirements
• The exhaust must be able to freely exit away from the
vehicle without any obstructions.
• Angle the exhaust pipe towards the rear of the vehicle,
so that exhaust fumes will naturally move away while the
vehicle is in motion. See Figure 18.
• Use standard 2” automotive-type exhaust piping and avoid
bends, if possible. A minimum 1.75” ID automotive-type
exhaust pipe may be used. See Figure 16 & Figure 20.
• A maximum of three 90° exhaust bends are allowed.
Reference Figure 14.
• Do not use galvanized pipe fi ttings (only black-iron pipe and
fi ttings should be used). Reference Figure 17.
• The total length of exhaust pipe should not exceed 27.5
feet.
• The Aqua-Hot is supplied with a 3 inch and 4 inch black pipe
nipple (1.5 inch diameter) along with a 1.5 inch exhaust
elbow. Reference Figure 18. These three exhaust system
components MUST BE utilized with all product installations.
Be sure to reference Figure 19 and 20 to determine which
exhaust nipple should be connected directly to the Aqua-
Hot’s exhaust port (the 3 inch of the 4 inch black pipe
nipple).
Exhaust System
The Aqua-Hot’s exhaust is HOT and must be kept away
from any heat sensitive material(s). Do NOT direct
exhaust downward as a fi re may result when parked in
dry, grassy areas.
All Aqua-Hot exhaust system installations MUST utilize the
two black pipe nipples and black pipe elbow, which are
provided with the heating system in the confi guration to be
suited for the particular RV application. Failure to conform
could create a hazardous situation and WILL void the Aqua-
Hot’s ETL Product Listing.
NOTE: Refer to “Internal Combustion Engine Exhausts and
Vehicle Wall Openings” in RVIA’s ANSI/NFPA 1192 Handbook
for the Recreational Vehicle Standards, as well as the
National Fire Protection Associations’ (NFPA) 1192 Standard
on Recreational Vehicles for additional information.
Installation Procedure:
1. Run the exhaust pipe to the driver’s side or to the back
of the vehicle and ensure that the exhaust fumes cannot
enter into the passenger compartment.
2. Be sure to secure the end of the exhaust pipe to the vehicle
with the proper exhaust hanger/support hardware.
NOTE: Should this particular application require more
than 27.5 feet of exhaust pipe, please contact Aqua-Hot at
574-AIR-XCEL (574-247-9235) for assistance.
Figure 16
1.5 inch ID Black Pipe Exhaust Fitting
1.75” ID Automotive-Type Exhaust Pipe

Fluid Expansion Bottle
©Aqua-Hot® 600D Installation Manual p. 11
Exhaust System
NOTE: The exhaust elbow can be rotated 270°,
as shown in the illustration; however, the exhaust
must not terminate beneath the vehicle or beneath
an open-able window or vent.
The two black pipe exhaust fi ttings MUST be utilized with all
installations! Failure to conform could create a hazardous
situation and will void the Aqua-Hot ETL Product Listing.
View from Underneath Aqua-Hot
1.5 inch Exhaust Port
Exhaust Elbow and
Nipples Assembly
NOTE: A maximum of three 90° bends are allowed
in the exhaust pipe. Also, the exhaust pipe cannot
be longer than 27.5 feet.
1.5 inch ID Black Pipe Exhaust Fitting
1.75” ID Automotive-Type Exhaust Pipe
Figure 18
Figure 17

Fluid Expansion Bottle
©Aqua-Hot® 600D Installation Manual p. 12
Exhaust System
Figure 19
Figure 20
3” Black Pipe
Nipple Installed
Black Pipe Elbow
4” Black Pipe
Nipple Installed
2” Automotive Type
Exhaust Pipe
Depth of Motor Home
Bay Floor
Exhaust Pipe
3” Nipple
Elbow
3” Nipple
Mounting Tray Flange
Mounting Tray Flange
Elbow
3” Nipple
Exhaust Pipe
3” Nipple
Depth of Motor Home
Bay Floor

Installing Heat Exchangers
©Aqua-Hot® 600D Installation Manual p. 13
Installation Requirements
Cozy heat exchangers can be mounted in one of two
confi gurations: either fl at on the ground, or vertically. Reference
Figure 21.
• Supply ventilation cross-sectional area of at least 29in2
(74cm2) must be supplied to each heat exchanger.
• Do not supply heat exchangers air which is drawn from the
bay areas; air supply should only be from the living areas.
• Return air should be drawn from the same room the heat
exchanger is heating.
• The antifreeze and water heating solution must fl ow in
through the bottom of the heat exchanger, and out the top
(reference Figure 24).
• In order to provide suffi cient ventilation, the return air
registers must be the same size, or larger, than the outlet
air registers.
Vertical Orientation
Horizontal Orientation
Figure 21
Figure 22
Heat Exchanger Locations and
Clearances
• Position the heat exchangers so that even heat is distributed
throughout the coach interior.
• The fi rst heat exchanger on the loop will output the most
interior heat.
• It is best practice to place the heat exchanger in an area
where it can be easily accessed for maintenance and
cleaning.
• Place the heat exchangers as close to the fl oor as possible
for best performance.
• If a heat exchanger is kept in the fresh water storage bay,
then the last heat exchanger in the coolant loop should be
used. See fi gure 22.
• The heating air supply may be fresh or recirculated air that
is drawn from a clean area not likely to be contaminated.
Aqua-Hot advises against placing a heat exchanger on the
slide-out section of any vehicle due to the high probability
of damage occurring to the heating loop from moving parts.
NOTE: Do NOT install more than four heat exchangers per
heating loop. If additional heat exchangers are required,
use a booster pump (not included) to provide additional
antifreeze fl ow capability.
Figure 23

Locations and Clearances
©Aqua-Hot® 600D Installation Manual p. 14
Mounting
Tabs (both
sides)
Inlet
Outlet
Figure 25
Figure 24
Installing Heat Exchangers
13.69 in
10.50 in 6.50 in 2.81 in 0.38 in
3.50 in
5.50 in
1.06 in
14.44 in
13.06 in
6.44 in

Locations and Clearances
©Aqua-Hot® 600D Installation Manual p. 15
Mounting the Heat Exchangers
1. Cut out a 2.5” H x 10” W (7cm x 26cm) opening for each
heat exchanger outlet and cold-air return grate as shown
in Figure 27.
2. Mount each heat exchanger permanently into place. There
are 4 tabs on both sides - see Figure 24.
3. Install the hot-air outlet and cold-air return grate.
A minimum of supply ventilation cross-sectional area of at
least 29in2 (74cm2) must be supplied to each heat exchanger.
If the toe-kick area is inadequate to house a heat exchanger
for regular installation, a plenum assembly may be purchased
to redirect air via ducting. Refer to Figure 26 & 28.
1 2 3 4 5
1. Hot Air Outlet Vent
2. Air Ducting Hose
3. Plenum
4. Cozy Heat Exchanger
5. Toe Kick Board
Mounting the Heat Exchangers
Figure 27
Figure 26
Figure 28
NOTE: When wiring the heat exchangers in parallel, the
main 18-gauge wire is split to allow the heat exchanger
wires to combine with the main wire to be powered or
grounded, respectively.
Figure 29
- (Ground) Black Wires
+ (Positive) Red Wires
NOTE: A return air register may not be required. However,
adequate return air must be provided to each particular
heat exchanger. This means that the total cross-sectional
area of the return air opening must be equal to or greater
than the cross-sectional area of the hot air outlet opening of
the heat exchanger.

Wiring Heat Exchangers
©Aqua-Hot® 600D Installation Manual p. 16
Wiring the Heat Exchangers
This section will explain in detail how to wire the heat
exchangers for optimal functionality. Do not deviate from these
guidelines. If a deviation is required, contact Aqua-Hot Heating
Systems prior to installing these exchangers for express
permission to proceed with modifi cations.
1. Wire each heat exchanger (in a heating zone) in parallel to
one another as shown in Figure 32.
2. Wire each heat exchanger independently to the J7 plug of
the Reporter.
3. Pin-out information is shown below.
NOTE: Night-mode functionality of the new controller requires
that the heat exchangers be wired directly into the controller.
Zone Fan Number Supply (+) Pin
Number
Ground (-) Pin
Number
1 J7-12 J7-9
2 J7-2 J7-5
3 J7-11 J7-8
4 J7-1 J7-4
5 J7-10 J7-7
Connector Part Numbers
Part Number Manufacturer Description
1-480706-0 TE Connectivity J7 Plug Housing
350550-1 TE Connectivity J7 Socket Terminal
J7 Mating Plug
Figure 30
Figure 31
Figure 32
1211
987
654
J7 Wire insertion view shown
321
10
J7 Socket Terminal

Plumbing the Heating Loop
©Aqua-Hot® 600D Installation Manual p. 17
Plumbing the Heating Loop
Once all heat exchangers have been mounted, plan the
routing of the plumbing lines from each heating zone to the
Aqua-Hot. The following guidelines should be used when
planning the coolant loop(s) for the heating zone. The order
of the heat exchangers should consider priority on the loop(s).
Failure to adhere to these installation principles can hinder the
operation of the heat exchangers.
• All plumbing should be installed as fl atly as possible.
• Extreme rises in height should be avoided to avoid any
potential air traps.
• Use ⅝” ID (Inside Diameter) plumbing lines, ¾” SAE J20
type coolant hose, heater hose, or PEX tubing for the
heating loop(s).
• Use wide-sweeping elbows or “bend supports” whenever
the plumbing lines may be susceptible to kinking.
• Plumbing lines should be run in areas where there is no
reasonable possibility that they can be pinched off or
damaged under normal operating conditions.
• Secure all lines where necessary and apply protective
shielding in areas where chafi ng may occur.
• Rubber coated/closed-type clamps are recommended
when securing the plumbing lines.
• Inlet and outlet plumbing lines can be installed with a
straight fi tting or an elbow.
• See Figure 34 for reference.
Instructions:
1. Layout the plumbing lines for all heat exchangers.
2. Label each line with the heating loop number and
designate as an outlet or an inlet line.
3. Connect and clamp the outlet line from the heater to
the lowest port (inlet port) with the longest run for both
heating loops.
4. Connect and clamp a line from the fi rst heat exchanger’s
highest port, and connect the other end to the next
heat exchanger’s lowest point.
5. Connect each additional heat exchanger in the same
arrangement.
6. Connect and clamp the inlet line from the heater to the
highest port on the last heat exchanger to complete
the heating loop.
Figure 34
Inlet
Outlet
PEX Insert Hose
Clamps ¾” Coupler
Figure 33
NOTE: Plumbing heat exchangers in this manner
will allow air to escape naturally. If air is trapped in
any heat exchanger, it will signifi cantly reduce the
exchanger’s overall heating performance.
NOTE: The kitchen and living room heat exchangers (up to
4) must be plumbed together in-series on “Heating Loop
3”. The fresh water tank and bathroom heat exchangers
must be plumbed together in-series on “Heating Loop 2”.
The bedroom heat exchanger must be plumbed on “Heating
Loop 1”. See the diagram below.
Heating Loop #2: Zone 2, 3, 4
Heating Loop #1: Zone 1
Incoming
Plumbing Lines
Outgoing
Plumbing Lines
Heating Loop #3: Zone 5

Plumbing the Heating Loop
©Aqua-Hot® 600D Installation Manual p. 18
Figure 35
Figure 37
Figure 36
Figure 38
Barbed Fittings Components Compression Fittings Components
Barbed Fittings Components Installed
Compression Fittings Components Installed
90° Connection Components
Straight Connection Components

Plumbing the Heating Loop
©Aqua-Hot® 600D Installation Manual p. 19
NOTE: For the best performance, the fi rst heat
exchanger should be placed where heat loss is the
greatest. The fi rst heat exchanger will always output
the largest volume of heat as compared to subsequent
exchangers.
NOTE: This is just a sample for mounting locations of the
Cozy heat exchangers. Actual placement and quantity may
vary on the individual design of the RV. For questions or
assistance, contact Aqua-Hot at 574-AIR-XCEL (574-247-
9235).
Figure 39
Heat Exchangers Layout
Figure 40