Aqua-Hot 100 Series User manual

Installation Manual
100Series
AHE-125-GN1

Introduction
©Aqua-Hot® 125-GN1 Installation Manual REV 220427 p. 1
Contents
Caution Notes...............................................................................1
Installation Checklist ...................................................................2
Introduction ..................................................................................4
System Features ..........................................................................7
Component Cut-Aways .................................................................9
Installing the Aqua-Hot ..............................................................11
Installation of the Expansion Bottle......................................... 12
Mounting the Burner to the Vehicle......................................... 13
Combustion Air & Exhaust System............................................14
Burner Harness ..........................................................................16
Connecting the Burner to the Aqua-Hot....................................19
Burner Connections .................................................................. 20
Burner Plumbing Requirements................................................21
Wiring the Aqua-Hot to the RV.................................................. 22
House Power Sense ...................................................................24
Connecting the 125GN to 12V DC Power................................ 25
Connecting the Aqua-Hot to AC Power..................................... 26
Installing Heat Exchangers........................................................27
Heat Exchanger Locations & Clearances ................................ 28
Mounting the Heat Exchangers................................................ 29
Wiring the Heat Exchangers ..................................................... 30
Plumbing the Heating Loop.......................................................31
Layout Example ......................................................................... 32
Domestic Water System............................................................ 33
Mounting the Aqua-Hot LCD ..................................................... 34
Operating the LCD & Aqua-Hot................................................. 35
Conguring the Zones................................................................37
RV-C Network Connectivity ....................................................... 38
Filling the Aqua-Hot................................................................... 39
Purging the Interior Heating Loop............................................ 40
Fuel Supply .................................................................................41
Fuel System ............................................................................... 42
Fuel Purge Procedure ............................................................... 45
Gas Burner Troubleshooting..................................................... 46
System Checks.......................................................................... 49
First Operation........................................................................... 50
Winterizing..................................................................................51
Flow Diagram............................................................................. 52
Appendix A: System Schematics.............................................. 53
Appendix B: Measuring Antifreeze............................................57
Appendix C: Parts & Accessories ............................................. 58
Warranty .................................................................................... 64
Caution Notes
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 ef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
must be observed.

IntroductionIntroduction
©Aqua-Hot® 125-GN1 Installation Manual REV 220427 ©Aqua-Hot® 125-GN1 Installation Manual REV 220427 p. 3p. 2
Installation Checklist Installation Checklist
Completed Description Page No.
RV Thermostats OR Thermistors wired to Aqua-Hot 22-23
House Power Sense wire connected 24
12VDC connected to Aqua-Hot 25
120VAC connected to Aqua-Hot 26
Cozy heat exchangers installed 27-29
Cozy heat exchangers wired 30
Cozy’s plumbed (in the bottom port, out through the top port) 31
Domestic Water System plumbed to the Aqua-Hot 33
Domestic Water Flow through the Aqua-Hot regulated to 0.8 GPM 33
Aqua-Hot LCD mounted in correct orientation 34
Heating Zones congured on LCD 37
Aqua-Hot lled with proper mixture of ethylene glycol/distilled
water heating solution 39
Aqua-Hot purged properly after lling 40
Fuel stand pipe installed in vehicle fuel tank 41
Fuel lines and connectors properly installed 42-44
Fuel system components connected to fuel line in order 42-44
Fuel line hose clamps fully tightened 42-44
Fuel system properly purged before operating the burner 45
System checks performed before rst operation 49
First operation properly performed 50
Completed Description Page No.
Aqua-Hot Installed 11
Expansion Bottle Mounted 12
Gas Burner Installed/Mounted 13
Gas Burner Combustion Air System Installed 14
Gas Burner Exhaust System Installed 15
Gas Burner Harness connected to Burner 16-18
Gas Burner Harness connected to fuel pump 18
Gas Burner Harness connected to fuse holder 18
Gas Burner Harness connected to vehicle battery 18
Gas Burner Harness connected to converter 18
Gas Burner Harness connected to Aqua-Hot 19
Aqua-Hot “to Heat Source” port connected to Burner “In” Port 19-21
Aqua-Hot “from Heat Source” port connected to Burner “Out” Port 19-21
Introduction:
The following table is a checklist of important items that
need to be completed for a successful install of the 125-GN1
Aqua-Hot heater in your RV. Please conrm each item is properly
completed before utilizing the Aqua-Hot heating system.
Should additional assistance be needed, please contact
the Technical Support team at 574-AIR-XCEL (574-247-9235),
Monday through Friday, between 7:00am and 4:00pm MST.
You can also email the service department at servicedept@
aquahot.com.
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.
WARNING!
Read and understand all instructions before installing the
Aqua-Hot unit and the external gas burner. 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.
Improper installation, adjustments, service and maintenance
can cause personal injury or loss of life. Reference the
installation and user manuals before installation or service.
Contact your authorized service or Aqua-Hot Heating Systems if
you have any questions before starting installation.
If the information in this manual is not followed
exactly, a re or explosion may result, causing
property damage, personal injury, or death.

IntroductionIntroduction
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Read all instructions before installing the Aqua-Hot unit and the
external gas burner. 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 speci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 RV 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 18 PSI. Exceeding this rating will cause internal
damage to the Aqua-Hot.
• Use caution when working on or near any propane/gas 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.
• Use special caution when children are present. Children
must not be allowed to play with the heater or perform
cleaning and maintenance.
• 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.
• At maximum operating temperature, the hot air outlet will
be very hot that may result in serious burns or injury. Be
aware of hot surfaces.
• The gas burner must be installed in a location that is
closed off from living quarters and accessible only from the
exterior of the vehicle.
• The burner produces very hot temperatures that can ignite
surrounding ammable materials. The burner should be
turned off when loading or unloading ammable materials.
If the information in this manual is not followed
exactly, a re or explosion may result, causing
property damage, personal injury or death.
Safety Features
Low-Voltage Shutdown
The Aqua-Hot Controller is designed to operate between
11V DC and 16V DC. If the Controller detects that it is
receiving voltage below 11.8V DC, a System Voltage fault
will trigger a display on the LCD screen. If the Controller
system drops below 11.2V DC for 30 seconds, it will
discontinue operation of the Aqua-Hot heating system.
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 Controller will deactivate
the heater and display an over-temperature fault on the
LCD display screen.
Low-Level Cutoff
If the system senses low uid levels, the heating system will
shut down all fans, heat sources, and pumps until the unit
is adequately relled.
House Power Sense
The Aqua-Hot Controller contains within it a fail-safe
functionality known as House Power Sense. This
functionality serves as a live signal to the Aqua-Hot allowing
it to continue operating. If power is lost to the on-board RV-C
network or other on-board control systems, the controller
is signaled to shut down operation until a 12V DC power
signal is returned to the unit.
As with any appliance, allow the Aqua-Hot to
completely shut down BEFORE disengaging
the RV 12V power disconnect.
Safe Installation of the Gas Burner
Be sure to become familiar with the installation process and the
documentation before installing in the vehicle.
• Make sure to protect the burner during installation. Do not
drop or stand on the burner.
• Avoid abruptly shutting down the burner prior to the purge
cycle. The burner fan will continue to run for several minutes
after being shut off to cool down and purge unused fuel.
• Only turn off the burner at the control panel in the interior
of the vehicle. Only shut down the burner via the battery
disconnect in the case of an emergency or danger.
• Do not disconnect the 12V DC power supply prior to the
purge cycle.
• Do not allow the wiring or wiring harness to come into
contact with sharp edges on metal panels. The wires can
become damaged and short circuit and potentially cause a
re. Use caution when installing the wiring.
• Protect any vehicle parts near the burner from excessive
heat damage, or from contamination from fuel.
• Make sure the internal combustion burner will not pose
a re hazard even in an overheat situation. Take care in
placing the burner with enough space from vehicle parts
and that the burner will have ample ventilation.
• The serial label must be visible and legible after the burner
has been installed.
• All precautions must be taken to minimize the risk of
personal injury or damage to the burner or vehicle.
• The burner may not be mounted in a position above the
125GN expansion tank.
Fuel Supply*
• Do not use the heater in enclosed spaces such as a garage.
The fumes produced from the exhaust can be toxic. Do not
use the burner while refueling or while other appliances are
being serviced or refueled.
• The fuel ller neck should be installed in a compartment
that is closed off from living quarters and must have a
tightly tting cap to prevent any fuel leaks.
• A visible, legible sign must be attached to the ller neck that
the burner be turned off before refueling. A similar warning
is included in the manufacturer’s operating manual.
Exhaust System
• Do not operate the burner in an enclosed space or a space
that does not have exhaust ventilation. Fumes from the
exhaust may be toxic.
• The exhaust system must be positioned so that the fumes
will not get into the interior of the vehicle through ventilation
openings or windows.
Combustion Air Inlet
• The burner combustion chamber air must not be taken from
the interior of the vehicle, only fresh air from the exterior.
• An intake line is required for the combustion air.
• The air inlet must be positioned in an unobstructed manner.
NOTE: Aqua-Hot recommends regular exercise of the Aqua-
Hot heating system to avoid issues with starting after a
several-month idle period.
*NOTE: The Fuel System requires that the gasoline used
(in the vehicle for the burner supply) must be 87 octane or
greater (87, 89, 91, or 93 octane).

System FeaturesIntroduction
©Aqua-Hot® 125-GN1 Installation Manual REV 220427 ©Aqua-Hot® 125-GN1 Installation Manual REV 220427 p. 7p. 6
System Overview
The Aqua-Hot 125GN is a Hydronic Heating System that can
provide heat and hot water on demand using a built-in electric
heating element and an external gas burner.
The Aqua-Hot Heating is a 2-in-1 System
1. Interior heating system: provides quiet, comfortable interior
heat and even temperatures.
2. Tank-less hot water system: provides a ow of comfortable
hot water.
The Aqua-Hot heating system heats an ethylene glycol
based antifreeze and distilled water solution that is stored in
the Aqua-Hot’s boiler tank. This uid solution must be up to
operating temperature before the Aqua-Hot will provide interior
heat or hot water. The tank-less hot water system produces
approximately 0.8 GPM of hot water.
To get the Aqua-Hot to temperature, turn the electric heating
element and/or the external gas burner to the “ON” position
on the Aqua-Hot LCD screen (shown below), or on the RV
control panel. It may take up to 20 minutes to get to operating
temperature before heat or hot water are available.
For continuous hot water or heat in colder conditions, it is
recommended to utilize the external gas burner. The electric
heating element will provide heat only in mild conditions and
provide light duty hot water needs.
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.
Important Notes:
• A qualied installer or service technician must perform
equipment installation or service. Contact Aqua-Hot for
Factory Authorized Service Centers or Certi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 specications of
your unit. Factory settings may be adjusted by the vehicle
manufacturer, conrm nal setting with your dealer.
• This heating system has been certied for installation only
in recreational vehicles, not certied for use in boats.
• The Aqua-Hot heating system operates independently of
the vehicle engine and is connected directly to the electrical
system of the vehicle. The gas burner is only connected
directly to the fuel system and the battery of the vehicle.
• Please read this manual and follow instructions to avoid
injuries during installation and/or operation.
Heat Priority Option:
The Aqua-Hot comes equipped with the three-way valve
(sometimes known as the summer/winter valve). This controls
the ow of the antifreeze and water heating solution within
the Aqua-Hot to deliver either hot water or interior as priority.
Tapping on this element will change the valve’s orientation.
When this element displays “INT. HEAT”, this valve is oriented
to provide interior heat by circulating the heating solution
throughout the interior heating zone. When the element says
“HOT WATER”, the valve is oriented so that the heating solution
is routed to prioritize hot water.
System Specications
Electric Element
Power Consumption......................................1500 W (maximum)
Voltage ..............................................................................110V AC
DC Power
Power Consumption.......................................... 57 W (maximum)
Zone Heat Circulation
Pumps...........................................................................................1
Power Consumption (max)............................................20W/1.7A
Voltage ............................................................................... 12V DC
Interior Heating
Maximum Heating Zones.............................................................3
Cozy....................................................... 6W/0.5A - 8,000 BTU/hr
Whisper............................................4.5W/0.37A - 4,000 BTU/hr
H.E. II................................................... 3W/0.25A - 4,000 BTU/hr
Domestic Water Heating
Maximum......................................................................... 0.8 GPM
Physical Specications
Dimensions (US)..............................17.66”L x 7.50”W x 11.50”H
Dry Weight ............................................................................45lbs.
Wet Weight............................................................................59lbs.
NOTE: Control Panel “Quiet Mode” reduces heat exchanger
power consumption by 20%
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.
NOTE: This product label is attached to the side of the
Aqua-Hot, and provides a ready reference to specications,
test standards, and important safety notices.
Figure 1

Component Cut-AwaysSystem Features
©Aqua-Hot® 125-GN1 Installation Manual REV 220427 ©Aqua-Hot® 125-GN1 Installation Manual REV 220427 p. 9p. 8
Aqua-Hot 125GN
1. Fluid Circulation Pump
2. Tempering Valve
3. Aqua-Hot Controller
4. Antifreeze and Water Heating Solution Tank
5. AC Electric Element
6. AC Activation Relay
7. Plate-to-plate Heat Exchanger
8. Three-Way Valve
9. Zone Air-Bleed Valve
10. Fluid Expansion Port (to overow bottle)
11. Zone Return
12. Fluid Fill Port
13. Zone Supply
14. Service Panel
15. External Gas Burner Supply
16. External Gas Burner Return
17. Domestic Cold-Water Inlet
18. Domestic Hot-Water Outlet
19. Domestic Low Point Drain
20. Cabinet Drain
Figure 5
Figure 4
11
13
14
15
17
18
10
9
19
20
12
16
3
12345
6 7 8 9
Figure 3
Figure 6
NOTE: The side panel in the view above has been made
transparent to aid in the explanation of the heater. DO NOT
remove this side panel. Doing so risks irreparable damage
to the Aqua-Hot. Only remove the service panel for service.
System Specications
Gasoline Burner
Heat Flow...............................................5,188 to 17,060 BTU/hr
Diesel Fuel Consumption...............................0.05 to 0.17 gal/hr
Coolant Pump................................................................20W/1.7A
Operating Pressure (med heat)....................................36.25 PSI
Flow Rate (minimum).....................................................36.25 PSI
Working Altitude .............................................................. 16,000ft
*Fuel
Fuel Type................................................GASOLINE ≥87 Octane
Fuel Consumption (Low Output)...................................... 0.05g/h
Fuel Consumption (High Output)......................................0.17g/h
DC Power
Consumption .................................................................10 to 37W
Operating Amp Range............................................... 0.83 to 3.8A
Operating Temperatures
Burner Operation ..................................................... -40 to 176°F
Burner Storage................................ .........................-40 to 248°F
Fuel Pump Operation ................................................. -40 to 86°F
Fuel Pump Storage...................................................-40 to 194°F
Physical Specications
Dimensions................................................ 8.8”L x 3.4”W x 6.9”H
Weight ..................................................................................6.3 lbs
TECHNICAL SPECIFICATIONS
Heating Medium Ethylene Glycol/Distilled Water
Thermal Power (W)
High Power Operation: 5000W
Low Power Operation: 1500W
Fuel GASOLINE (87 Octane or higher)
Fuel Consumption
(gallons per hour)
Low power operation: 0.05 g/h
High power operation: 0.17 g/h
Power supply (battery
for the engine) DC12V
Power Consumption (W)
At start <100 W
High power operation: 37 W
Low power operation: 10 W
Working pressure (MPa) 0.25
Lowest working
temperature -40°F
Net Weight (heater
only) 10.6lbs
Working height
(above sea level) 16,405 ft
Weight of Main Heater 6.3lbs
Temperature of Coolant
when blower is started 113°F
Figure 2
NOTE: This product label is attached to the top of the
burner and provides a ready reference to specications,
test standards, and important safety notices.
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.
*NOTE: The Fuel System requires that the gasoline used
(in the vehicle for the burner supply) must be 87 octane or
greater (87, 89, 91, or 93 octane).

Support and ClearanceComponent Cut-Aways
©Aqua-Hot® 125-GN1 Installation Manual REV 220427 ©Aqua-Hot® 125-GN1 Installation Manual REV 220427 p. 11p. 10
Figure 7
Support and Clearances
Make the following considerations when supporting the
Aqua-Hot to ensure its most optimal operation and location.
Dimensions for the mounting tabs are shown below.
• Ensure that the oor of the mounting location can support
at least 70lbs.
• Use a #10 screw (5mm) to secure the Aqua-Hot in place on
the RV oor. Use at least 1 screw per mounting tab (3 tabs).
• The best place for the Aqua-Hot heating system is in a
cabinet or storage space, making sure there is ample
space to remove the service panels on the top and side.
Installing the Aqua-Hot
Install the Aqua-Hot in a compartment which protects the
unit and allows service access to the top and front panel of the
Aqua-Hot.
1. Reference the following illustrations below for mounting
information.
2. Secure the Aqua-Hot to the vehicle oor using appropriate
mounting hardware to suit ooring material and tolerances.
3. The Aqua-Hot is best placed where easy access to the top
and front is guaranteed for service.
Figure 11
TOP View
Figure 12
SIDE View
6
14
12
15
1
9
18
20
19
10
4
11
7
17
3
8
2
Belief Gas Burner
1. Combustion Air Fan
2. Burner Outer Casing
3. Burner Inner Casing
4. Combustion Chamber
5. Glow Plug
6. Flame Sensor
7. Temperature sensor
8. Over-Heat Sensor
9. Burner Controller
10. Air Inlet Pipe
11. Mufer
12. Fuel Pipe
13. Coolant Pump
14. Fuse
15. Main Wire Harness
Connector
16. Fuel Pump
17. Exhaust Pipe
18. Coolant outlet Pipe
19. Coolant Inlet Pipe
20. Burner
Figure 8
Figure 9
Figure 10
16
5
Figure 13
Figure 14
13
Mounting Tab Detail
0.75”
Center-to-center
.196” Ø
(#10)
Installing the Aqua-Hot
TOP VIEW
Aqua-Hot
Front
Connections
Edge of Installation Area
Mounting Tab
x3
Service Clearance
4” minimum
Service Clearance
8” minimum

Fluid Expansion BottleFluid Expansion Bottle
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The uid expansion bottle is integral to the operation of the
Aqua-Hot. It provides an area for hot, expanded uid to empty
into, and also protects the Aqua-Hot from low-uid, which could
lead to catastrophic damage of the Aqua-Hot.
Follow the directions in this section to correctly install the uid
expansion bottle.
Installation Procedure:
1. Place the expansion bottle in position on the side of the
Aqua-Hot or other mounting location in the RV.
2. Secure the expansion bottle using either self-tapping
screws driven into the dimples in the area of the Aqua-
Hot shown in below, or mounting hardware specic to the
NOTE: Before securing the expansion bottle to the side of
the Aqua-Hot or its mounting location, the boiler tank must
be lled with the heating solution. The expansion bottle must
be higher than the unit for this to happen to avoid air locks.
See “Filling the Aqua-Hot” on page 39 for more information.
NOTE: Avoid any bends or dips in the over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 bottle.
Hot Fluid Line
Cold Fluid Line
Fluid Level Sensor
Fill Cap
Lower Fitting
Upper Fitting
Figure 17
Figure 16
Fluid Fill Port
Expansion Bottle
Connection
Figure 18
Install the external gas burner in a location separate from the
living spaces that protects the unit, and also allows service
access to the burner.
• Reference the illustrations below for mounting information.
• The burner is best placed in a location where it can be
easily accessed for service and maintenance.
• The burner must not be mounted higher than the expansion
bottle.
• The bracket must be secured to the vehicle with at least 4
M6 screws.
• Fasten the burner bracket rmly, the 4 corners should be
lined with rubber shock absorbers. The burner must be
fastened on the bracket with (4) M6 bolts (see Figure 20).
Before drilling holes in the vehicle, consult the
manufacturer for recommendations and limitations.
Do NOT weld to the vehicle frame.
Mounting the Burner
Figure 15
Figure 20
(4) M6 Bolts
Mounting Bracket
Figure 22
Figure 19
Ø 0.52in (x4)
Mounting Bracket Dimensions
4.85”
5.28”
12.56”
10.81”
Fluid Level Sensor
Hole in the RV bay oor for overow hose
Expansion hose. Must vent to
the exterior of the vehicle
mounting location in the RV. Please only use the length
of hose provided, or less, if the bottle is not mounted to
the side of the Aqua-Hot. Additionally, there should be a
gradual rise from the Aqua-Hot to the expansion bottle if it
is not mounted to the Aqua-Hot.
3. Drill a hole in the oor of the RV to allow the overow tube
to vent to the exterior of the vehicle (Figure 16).
4. Cut the hoses to length if necessary.
5. Place a hose which runs from the lower tting of the
expansion bottle to the expansion bottle connection shown
in Figure 17. Secure this hose in place with 2 constant
tension hose clamps.
6. Place the overow hose so that it connects to the upper
tting of the expansion bottle, and exits through the hole
drilled through the RV oor in step 3 (Figure 16). Secure
this hose to the upper tting with a constant tension hose
clamp.
7. Locate the wires of the expansion bottle and connect them
to wires J43 and J44 on the wiring harness.
Mount bottle
here
• The burner can be oriented to suit different orientations/
positions, however it should not exceed an angle greater
than 90°. The recommended orientation is horizontal with
the exhaust pipe vented downwards.
• If mounting to the frame rail, use (4) M6 bolts. Drill (4) M6
holes where the burner will be mounted, and fasten the
bracket to the vehicle with (4) M6 bolts.
• Secure the burner to the bracket using appropriate
mounting hardware, M6*95 bolts torqued to 6 lb-ft.
Mounting the Burner to the Vehicle
Figure 21
(1) M6-95 Bolt
Installation of the Expansion Bottle

Fluid Expansion BottleFluid Expansion Bottle
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Combustion Air System Exhaust System
The combustion air should not be supplied from living areas.
The air intake opening must not point in the direction of travel.
It also should be free from potential clogs from snow, debris, or
water.
• Installation of air intake and exhaust system is shown in
Figure 24.
• There is no air pressure difference between the exhaust
outlet or combustion air inlet.
• The combustion air intake must be positioned in a way that
the intake will not terminate within the vehicle interior or
near the burner’s exhaust pipe.
• The air intake tube must be located in a cool place.
• The combustion air intake must be positioned high enough
so splashing water cannot come into contact.
• It must be positioned as to not become clogged with dirt
or debris.
• It should not be able to draw in exhaust fumes.
• It must be positioned away from the face of travel.
NOTE: The air intake tube cannot be installed downward. A
water drain hole (Ø 2-5) is to be made at the lowest point.
The tube should be installed in a position that stays as cool
as possible and protected from splashing water.
The specications and requirements must be followed carefully.
Failure to follow instructions may result in improper and unsafe
operation of the 125-GN1 and burner. Please comply with all
applicable legal requirements.
• Do not direct exhaust downward, as re may result when
the vehicle is near dry, grassy areas.
• Exhaust must not terminate beneath the vehicle or beneath
a window or vent.
• Ensure that the exhaust pipe is routed away from any
awnings or slide-out areas.
• Position the exhaust pipe away and towards the rear of the
vehicle so the fumes naturally move away while the vehicle
is in motion and cannot permeate the interior of the RV.
Instructions
The exhaust pipe, with an inside diameter of 0.94in (24mm),
can be routed with several bends, total not to exceed 270°,
and a minimum bending radius of 2in (50mm). The total length
must not exceed 2.3’ (700mm).
Figure 25
Figure 26
The combustion air intake may be installed in the same
compartment as the vehicle’s fuel tank, but the air intake must
come from the exterior. The exhaust must be routed to the
exterior and any holes must be splash-proof.
Refer to the “Internal Combustion Engine Exhaust and Vehicle
Wall Openings” in RVIA’s ANSI/NFPA 1192 Handbook for
Recreational Vehicle Standards, as well as the National Fire
Protection Association’s (NFPA) 1192 Standard on Recreational
Vehicles for relevant information.
The exhaust pipe should be cut to form two sections: the
exhaust pipe and exhaust tail-pipe. The mufer will be installed
in the middle and xed with the mufer holder. It may not be
fastened to temperature-sensitive vehicle parts. There should
be at least 0.8in (20mm) between the mufer, or exhaust, and
temperature-sensitive parts. Thermal insulation may be used
on the exhaust pipe.
It is recommended to route the exhaust pipe in a downhill slope.
If it is not possible, drill drain holes (Ø2-5mm) at the lowest
points.
The exhaust pipe opening should not extrude out past the
vehicle. The opening should prevent intake from the air inlet
pipe. The opening should be away from the direction of travel.
Rigid, stainless steel with a minimum wall thickness of 0.04in
(1mm) or exible piping of the same material may only be used
as the exhaust pipe. The exhaust pipe is secured to the mufer
using supplied exhaust clamps.
Exhaust Outlet Requirements
• The exhaust gas must be able to ow freely.
• The exhaust outlet must not be clogged with snow or debris.
• Exhaust outlet must not face in the direction of travel.
• Exhaust fumes may not enter the interior of the vehicle via
windows, doors, or other openings.
• The exhaust gas cannot be drawn in for the combustion air.
• The exhaust opening may not be close to the ground.
• If the vehicle has an under-body, the exhaust opening must
extend at least ⅜ in (10mm) past the vehicle.
• The exhaust line must be secured with clamps (2 each) in
the proper locations.
NOTE: Exhaust parts are at high temperatures when the
heater is operating. They shall be installed far away from
plastic parts and wires of the vehicle to avoid damage. The
air inlet pipe and exhaust pipe can freeze easily in working
conditions and should be checked regularly for obstructions.
NOTE: Should this particular application require
modication, please contact Aqua-Hot Heating Systems at
574-AIR-XCEL (574-274-9235) for further assistance.
Figure 24
Exhaust Pipe - Stainless Steel
1Burner
2Air Inlet Pipe
3Exhaust Pipe
4 Mufer
5Exhaust Tail Pipe
6 7 Protective Hoods
8Air Filter
1
268 3 4 5 7
Exhaust Connection
BURNER EXHAUST CONNECTION
Figure 23
Combustion Air Connection
BURNER AIR CONNECTION
The direction of the exhaust outlet must directed away from
any heat sensitive or highly ammable parts. Failure to do
so will result in a re. Exhaust cannot be routed through the
interior of the vehicle, only the exterior. Failure to do so can
cause exhaust gas to leak inside the vehicle causing illness
and/or death.
Combustion Air System Exhaust System

Fluid Expansion BottleFluid Expansion Bottle
©Aqua-Hot® 125-GN1 Installation Manual REV 220427 ©Aqua-Hot® 125-GN1 Installation Manual REV 220427 p. 17p. 16
Burner Harness Burner Harness
B4 Plug:
The B4 plug is the connector for the burner to the Aqua-Hot.
Manufacturer Part No. Common Name
TE Connectivity 350766-4 3-Pin Mate-N-Lok
Receptacle Connector
TE Connectivity 350690-2 Pin
TE Connectivity 350551-6 Socket
B4 Connector
Figure 30
B3 Plug:
The B3 plug is the connector for the fuel pump to the gas burner.
Manufacturer Part No. Common Name
TE Connectivity 282104-1 Socket Housing
TE Connectivity 282404-1 Terminal
TE Connectivity 281934-4 Wire Seal
B3 Connector
Figure 29
B1 Plug:
The B1 plug is the connector to the gas burner.
Manufacturer Part No. Common Name
TE Connectivity 2109441-4 Socket Housing
TE Connectivity 1-968857-1 Terminal
TE Connectivity 828905-1 Wire Seal
TE Connectivity 828922-1 Plug, Blue (Pins 1, 2, & 5)
B1 Connector
Figure 27
Gas Burner Wire Harness
The gas burner and connectors will need to be properly installed.
Please note that the connectors will not t in incorrect positions.
The connectors and information are shown below.
F1 Fuse Holder:
The F1 Fuse holder, with 20A fuse.
Manufacturer Part No. Common Name
Packard 15300027 Female Connector
Aptiv 12129493 Terminal
Aptiv 15300014 Lock
Aptiv 15324983 Seal
Aptiv ES10 Cover
Packard - 20Amp Fuse (included)
F1 Fuse Holder
Figure 33
B2 Plug:
The B2 plug is the connector for the converter.
B2 Connector
Figure 31
X3 Plug:
The X3 plug is the connector for the Aqua-Hot to the burner.
Manufacturer Part No. Common Name
TE Connectivity 1586849-1 3-Pin Mate-N-Lok
Receptacle Connector
TE Connectivity 350690-2 Pin
TE Connectivity 350551-6 Socket
X3 Connector
Figure 28
K_Line Converter:
The K_Line converter connects the burner to the Aqua-Hot. The
LEDs show the operation of the converter. They can be found on
the side of the converter. Reference the images below for more
information.
K_Line Converter
Figure 34
Figure 35
K_Line Converter TOP
View LEDs Description
Converter Side Connector
Burner Side Connector
NOTE: It is recommended to mount the K_Line
Converter using double-sided Velcro on the Aqua-Hot
cabinet, either on the top, in-between ports, or either
side of the cabinet where space allows.
Figure 32

Fluid Expansion BottleFluid Expansion Bottle
©Aqua-Hot® 125-GN1 Installation Manual REV 220427 ©Aqua-Hot® 125-GN1 Installation Manual REV 220427 p. 19p. 18
Burner Harness
8. Locate the Aqua-Hot wire harness (Part No. ELE-125-100)
and the burner harness (Part No. GBX-125-112). The
connectors for the Aqua-Hot harness and the burner
harness are shown below. Reference pages 16-17 for more
information on the burner connectors and page 18 for the
full burner harness diagram.
9. To connect the burner to the Aqua-Hot, simply attach the
Aqua-Hot plug (X3) to the burner plug (B4). The table below
shows more detail for what the pins are for.
Pin Number Description
1ON/OFF
2 Ground
3 Input Burner Status
10. Organize and tidy the wires that lead to the burner and the
Aqua-Hot to protect them from damage and short circuits.
Figure 40
Figure 41
B4 Burner Connector
Burner Harness
X3 Aqua-Hot Connector
Aqua-Hot Harness
Installation Instructions
1. Mock-up the locations for the gas burner and the Aqua-Hot
within the RV to ensure that there is adequate room for
access of the burner and the Aqua-Hot.
2. Verify the Aqua-Hot is secured in place.
3. Position and secure the gas burner in place.
4. Mount the K-Line Converter using double-sided Velcro on
the Aqua-Hot cabinet, either on the top, in-between ports,
or on either side of the cabinet where space allows.
5. Reference the image below for the burner for the supply
and return ports for the antifreeze and water heating
solution.
6. Connect the gas burner return and supply hoses to the
Aqua-Hot as indicated by the image below.
7. Secure the plumbing to the burner with constant tension
hose clamps.
“To Heat Source”
(Supply/In)
“From Heat Source”
(Return/Out)
Figure 37
“To Heat Source”
(Out)
“From Heat Source”
(In)
Figure 38
Connecting to the Aqua-Hot
BURNER HARNESS DIAGRAM
To Fuel Pump
To Burner
To Aqua-Hot
Figure 36
NOTE: It is recommended to
mount the K_Line Converter
using double-sided Velcro on
the Aqua-Hot Cabinet, either
on the top, in-between ports,
or either side of the cabinet
where space allows.
Figure 39
Connecting the Burner to the Aqua-Hot
These instructions will cover the installation and power connections for the gas burner to the 125GN.
Burner Harness Part No.
GBX-125-112

Fluid Expansion BottleFluid Expansion Bottle
©Aqua-Hot® 125-GN1 Installation Manual REV 220427 ©Aqua-Hot® 125-GN1 Installation Manual REV 220427 p. 21p. 20
Figure 42
Burner Connections
Plumbing Requirements
The plumbing lines are how the uid is transferred from the
Aqua-Hot to the burner and back to the Aqua-Hot to transport
heat to domestic water and to the interior of the RV.
Properly installing the coolant hoses to the Aqua-Hot from the
burner are integral to the correct and safe operation of the
heating system.
Reference the requirements below to ensure the plumbing lines
are properly installed.
• Hoses used in this installation must comply with SAE 20 R3
specications.
• The plumbing hoses should avoid any bends or dips as
these can cause excess air in the lines, not allowing the
ow of coolant to properly ow.
• The hose clamps must be tightened with a torque of 40
lb-in (4.5 Nm).
• Reference the plumbing diagram below for an example of
how the burner should be plumbed with the 125GN.
Gas Burner
Expansion Bottle
Aqua-Hot 125GN
Figure 43
Figure 45
NOTE: This diagram below is simply a reference to show
the layout and ow of the plumbing to and from the
heaters. Placement may vary depending on the RV.
Plumbing Requirements
Figure 44
Burner Supply
Burner Return
Burner Connections
Please reference the instructions below and the image in Figure 42.
• The circulation pump inlet should be below the coolant outlet port to eliminate air in the line when installing.
• Verify the inlet and outlet ports on the burner prior to installing hoses. The correct direction of the coolant ow must be
determined.
• Secure hose connections using hose clamps, tightened with a torque of 40 lb-in (4.5 Nm).
BURNER COOLANT SYSTEM DIAGRAM
Circulation
Pump
Gas
Burner
Circulation
Pump
Gas Burner
Supply Port
Gas Burner
Hose Clamps

Introduction to WiringIntroduction to Wiring
©Aqua-Hot® 125-GN1 Installation Manual REV 220427 ©Aqua-Hot® 125-GN1 Installation Manual REV 220427 p. 23p. 22
J7 Plug
The J7 plug is responsible for managing all zone fan power
connections, and boost pump supply and return.
Manufacturer Part No. Common Name
TE Connectivity 1-480706-0 9-Position Mate-N-Lock
TE Connectivity 350550-1 Mate-N-Lock Power Contacts
Once all the required hardware has been acquired, wire the J7
plug according to the table below. J7-9 is not used.
Pin Number Function Connect To
J7-1 Fan 1 Output Zone 1 Fans (+)
J7-2 Fan 2 Output Zone 2 Fans (+)
J7-3 Fan 3 Output Zone 3 Fans (+)
J7-4 Fan 1 Ground Zone 1 Fans (-)
J7-5 Fan 2 Ground Zone 2 Fans (-)
J7-6 Fan 3 Ground Zone 3 Fans (-)
J7-7 Boost Pump Output Boost Pump +
J7-8 Boost Pump Ground Boost Pump -
J7-9 Input Burner Status
1 2 3
4 5 6
7 8 9
J7 Wire insertion view shown
Figure 46
J8 Plug
The J8 plug is meant to handle the zone thermostats and House
Power Sense functionality. House power sense functionality will
be described in detail later in this manual.
Manufacturer Part No. Common Name
TE Connectivity 350782-1 9 Position Mate-N-Lock
TE Connectivity 350550-1 Mate-N-Lock Power Contacts
Once the required hardware has been acquired, wire the J8
plug according to the table below.
Pin # Function Connect To
J8-1 Zone 1 Input from
Thermostat/Thermistor Zone 1 Thermostat
J8-2 Zone 1 Output from
Thermostat/Thermistor Zone 1 Thermostat
J8-3 UNUSED/SPARE UNUSED/SPARE
J8-4 Zone 2 Input from
Thermostat/Thermistor Zone 2 Thermostat
J8-5 Zone 2 Output from
Thermostat/Thermistor Zone 2 Thermostat
J8-6 UNUSED/SPARE UNUSED/SPARE
J8-7 Zone 3 Input from
Thermostat/Thermistor Zone 3 Thermostat
J8-8 Zone 3 Output from
Thermostat/Thermistor Zone 3 Thermostat
J8-9 House Power Sense 12V DC Power (+)
Figure 47
1 2 3
456
789
J8 Wire Insertion View Shown
Installation must be performed by a professional
installer or technician as per national/local regulations.
Improper installation can cause property damage, injury,
or death.
Wiring the Aqua-Hot
J3 Plug
The J3 plug connects to the on-board RV-C system of the RV. It is a
4-pin connector with self contained power pins. See the diagram
below for the crimping information for the J3 plug. Crimp these
parts together using pliers.
Manufacturer Part No. Description
3M 37401-2165-000 FL 100 4-Position MALE
Plug
3M 37104-2165-000 FL 100 4-Position FEMALE
Receptacle
General
Cable E2104S.41.02 4COND 22AWG WHT SHLD Cable
The parts listed above can be purchased from any major electronics
retailer. Only the parts listed above are approved for use in the
Aqua-Hot.
Pin Number Description
J3-1 12V DC Power
J3-2 Data
J3-3 Data
J3-4 Ground
Figure 48
Wiring the Aqua-Hot
Wiring the Aqua-Hot
This section will introduce the basic considerations, practices, and information necessary to wire the Aqua-Hot to any relevant
RV-side systems. The following section will outline the basic pin out information for the two RV-side plugs.
Wiring the Aqua-Hot (continued)
The following section will outline the basic pin out information
for the RV-C system of the RV.
12V DC Power (J3-1)
Ground (J3-4)
Data (J3-2, J3-3)

Providing DC PowerHouse Power Sense
©Aqua-Hot® 125-GN1 Installation Manual REV 220427 ©Aqua-Hot® 125-GN1 Installation Manual REV 220427 p. 25p. 24
Special
If for some reason pin J3-1 cannot be supplied
with power, supply 12V DC power to the J8-9
pin.
Typical
The typical use case in wiring the House Power
Sense requires a constant 12V DC signal on
plug J3-1 for the House Power Sense. Plug J3
is the 4-position RV-C plug. This is the easiest
way to implement House Power Sense on
vehicles with on-board Multi-Plex systems.
DO NOT connect 12V DC power to the Aqua-Hot if
the vehicle requires welding. Electrical welding
will cause serious, irreversible damage to the
Aqua-Hot.
The section will outline the requirements, steps, and
information necessary to connect the Aqua-Hot to the vehicle’s
12V DC power system. Follow all guidelines and pay attention to
all notes contained herein. Failure to adhere to these guidelines
can inhibit unit performance, and may cause damage to the
Aqua-Hot and/or the RV.
• Installation must be performed by a qualied, professional
according to current national regulations. Reference
A119.2/NFPA 501C Standard on Recreational Vehicles
1993 Edition for relevant national regulatory information.
• Select the correct wire gauge for installation referencing
ANSI/RVIA-LV.
• Protect the Aqua-Hot from over-current and shorting by
incorporating a 20A breaker (minimum) to the Aqua-Hot’s
RV-side power connection.
• The 12-volt supply to the heater must be routed directly
from the battery.
• All power circuits must be protected with fuses or automatic
circuit breakers.
• The 14AWG RV power and ground wires go directly into the
butt splice shown below.
• Cover splice crimp with heat shrink once complete.
Figure 51
J3 Wire Insertion View Shown
Figure 49
Figure 52
Butt Splice - Power
D11 RV Power
Figure 53
Butt Splice - Ground
D12 RV Ground
NOTE: The image above is simply a reference. A professional,
licensed installer needs to determine the necessary
components and conguration according to local codes and
standards.
J8 Wire Insertion View Shown
Figure 50
1 2 3
456
789
Negative/Ground
Positive/Power
In-Line
Fuse
Main Battery
Disconnect
+
-
Vehicle Battery
House Power Sense
The Aqua-Hot Controller contains within it a fail-safe functionality known as House Power Sense. This functionality serves as a
live signal to the Aqua-Hot allowing it to continue operating. If power is lost to the on-board RV-C network or other on-board control
systems, the Controller is signaled to shut down operation until a 12V DC power signal is returned to the unit.
Wiring for House Power Sense
In order for the Aqua-Hot to function correctly and to maintain the fail-safe nature of the House Power Sense, supply 12V DC
power to either the J8-9 pin OR to the J3-1 pin. Do NOT supply power to both of these pins.
Wiring for Multi-Plex Systems
When wiring for Multi-Plex Systems, route a power wire from a power connection on the RV-C system to the Aqua-Hot’s J3-1 pin
(that is, plug J3, pin 1). The House Power Sense will not function correctly if 12V DC power is not supplied from a device on the
RV-C network.
Routing the wire from the RV-C network (or from an accessory on the RV-C network) ensures that if the RV-C network goes off-
line (but the vehicle remains otherwise powered), the Aqua-Hot will not continue to operate unabated.
There are two ways to wire the House Power Sense for use with a Multi-Plex network; typical wiring case and a special wiring
case.
Connecting the 125GN to 12V DC Power

Installing Heat ExchangersProviding AC Power
©Aqua-Hot® 125-GN1 Installation Manual REV 220427 ©Aqua-Hot® 125-GN1 Installation Manual REV 220427 p. 27p. 26
Cozy heat exchangers can be mounted in one of two
congurations: either at on the ground, or vertically. Reference
Figure 58.
• 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.
• Return air should be drawn from the same room the heat
exchanger is heating.
• The anti-freeze and water heating solution must ow in
through the bottom of the heat exchanger, and out the top
(reference Figure 69).
• The Aqua-Hot 125GN is designed to work with up to 3
thermostatic heating zones.
Vertical Orientation
Horizontal Orientation
Figure 58
Figure 59
Figure 55 Figure 56 Figure 57
AC Electric Connection
Figure 54
The following section will detail how to connect the Aqua-
Hot to the vehicle’s AC electric system. Connect the 3-pin Molex
connector to the coach-side AC electric system in order to utilize
the Aqua-Hot’s AC heating element.
The Aqua-Hot utilizes Molex 19403 and 19045 series con-
nectors for the AC electrical circuit. These are self-contained
connectors which can be readily purchased from your choice
of electronics supplier. Listed below are three different mating
connections.
Self-Contained Power Connector - 2 Circuit for Solid Wire
Size Part Number Housing Color
12-14AWG
(2.00mm2)19045-1000 White
Self-Contained Power Connector - 2 Circuit for Stranded Wire
14-16AWG
(2.00mm2)19403-1011 Blue
12AWG
(2.00mm2)19403-1010 Yellow
• Installation must be performed by a qualied profession-
al according to current national regulations. Reference
A119.2/NFPA 501C Standard on Recreational Vehicles
1993 Edition.
• The boiler must be connected to a 120V AC supply perma-
nently and be protected with a 20A breaker (minimum). The
120V AC must be separate from 12V DC.
• It must be possible to disconnect the power to the boiler,
either an easily accessible plug or a circuit breaker.
• Please refer to the schematic on page 56.
Molex 19045-1000 Molex 19403-1011Molex 19403-1010
Connecting the Aqua-Hot to AC Power Heat Exchanger Installation Requirements

Locations and ClearancesLocations and Clearances
©Aqua-Hot® 125-GN1 Installation Manual REV 220427 ©Aqua-Hot® 125-GN1 Installation Manual REV 220427 p. 29p. 28
• Position the heat exchangers so that even heat is distributed
throughout the RV interior.
• The 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.
• Place the heat exchangers as close to the 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.
• 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.
Figure 60
Figure 61
1. Cut out a 2.5” x 10” (7cm x 26cm) opening for each heat
exchanger outlet and cold-air return grate as shown in
Figure 63.
2. Mount each heat exchanger permanently into place. There
are 4 tabs on both sides - see Figure 69.
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 62 & 64.
1 2 3 4 5
Mounting the Heat Exchangers
Figure 62
Figure 63
Figure 64
Heat Exchanger Locations and Clearances Mounting the Heat Exchangers
1. Hot Air Outlet Vent
2. Air Ducting Hose
3. Plenum
Plenum Assembly
4. Cozy Heat Exchanger
5. Toe Kick Board

Plumbing the Heating LoopWiring Heat Exchangers
©Aqua-Hot® 125-GN1 Installation Manual REV 220427 ©Aqua-Hot® 125-GN1 Installation Manual REV 220427 p. 31p. 30
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 modications.
Instructions
1. Wire each heat exchanger (in a thermostatic zone) in
parallel to one another as shown in Figure 67.
2. Wire each heat exchanger independently to the J7 plug of
the unit controller.
3. Pin-out information is shown below.
NOTE: Quiet-mode functionality of the new controller requires
that the heat exchangers be wired directly into the controller.
NOTE: The 125GN can have up to 3 individual, thermostatic
heating zones. The heat exchangers in different zones are
wired to a different set of pins of the J7 plug.
Figure 66
J7 Mating Plug
Figure 67
Figure 65
1 2 3
4 5 6
7 8 9
J7 Wire insertion view shown
The following guidelines should be used when planning the
coolant loop for the heating zone. The 125GN requires a single
uid zone. The order of the heat exchangers should consider
priority on the loop. Failure to adhere to these installation
principles can hinder the operation of the heat exchangers.
• All plumbing should be installed as atly as possible.
• Extreme rises in height should be avoided to avoid any
potential air traps.
• Use ⅝” ID plumbing lines, ¾” SAE J20 type coolant hose,
heater hose, or PEX tubing for the single heating loop.
• 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 cha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 tting or an elbow.
Instructions
1. Layout the plumbing lines for all heat exchangers (see the
example in Figure 71).
2. Label each line 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).
4. Connect and clamp a line from the 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.
Mounting
Tabs (both
sides)
InletOutlet
Figure 69
NOTE: This diagram below is simply a reference to show the
layout and ow of the plumbing to and from heat exchangers.
Placement and quantity may vary depending on the RV.
Inlet
Outlet
PEX Insert Hose
Clamps ¾”
Coupler
Figure 68
Zone Return
Zone Supply
Figure 70 Figure 71
Aqua-Hot
Heating System
Cozy #2 Cozy #3Cozy #1
Wiring the Heat Exchangers
Thermostatic
Zone Number
Supply (+) Pin
Number
Ground (-) Pin
Number
1 J7-1 J7-4
2 J7-2 J7-5
3 J7-3 J7-6
Connector Part Numbers
Part Number Manufacturer Description
1-480706-0 TE Connectivity J7 Plug Housing
350550-1 TE Connectivity J7 Socket Terminal
J7 Socket Terminal
Plumbing the Heating Zone

Domestic Water SystemPlumbing the Heating Loop
©Aqua-Hot® 125-GN1 Installation Manual REV 220427 ©Aqua-Hot® 125-GN1 Installation Manual REV 220427 p. 33p. 32
NOTE: This is just a sample for the layout of the gas burner with
the Aqua-Hot and heat exchangers. Actual placement may vary
on the individual design of the RV. For questions or assistance,
contact Aqua-Hot at 574-AIR-XCEL (574-247-9235).
Layout Example
Figure 73
Domestic Water System Requirements
• Reference A119.2/NFPA 501C Standard on Recreational
Vehicles 1993 Edition for relevant regulatory information
regarding the design of Domestic Water Systems.
• The Aqua-Hot is equipped with a pressure relief valve and a
tempering valve in order to provide safe hot water without
chance of scalding or an over-pressurized system.
• Plumb the domestic water system according to Figure 75.
Plumbing the Domestic Water System
The Aqua-Hot is also able to provide domestic hot water
while the boiler tank is up at operating temperature. Activate
the external gas burner to provide adequate heat for hot water
needs. The electric element will only provide light duty hot water.
The tempering valve is integrated into the cabinet of the
Aqua-Hot, and is set upon departure from the Aqua-Hot factory.
So long as the tempering valve is not modied, it will provide
hot, non-scalding water.
Instructions
1. Locate the domestic cold water inlet (blue PEX tube) and
connect it to the vehicle’s domestic cold water system.
2. Locate the domestic hot water outlet (red PEX tube) and
connect it to the vehicle’s domestic hot water system.
NOTE: Extended exposure to household bleach will corrode the
components of the Aqua-Hot that will potentially dramatically
shorten the operational lifetime of the Aqua-Hot. Under no
circumstances is the Aqua-Hot to be exposed to household bleach
for extended periods of time. This type of damage is not covered by
the Aqua-Hot warranty.
Domestic Cold
Water Inlet
Domestic Hot
Water Outlet
Figure 74
To Hot Water
Faucets
Tempered
Domestic Hot Water
Fresh Water
Storage Tank
Cold Water Faucets
Demand Pump
Figure 75
Cozy #1
Living Space
Aqua-Hot
Heating System
Figure 72
Gas Burner
Cozy #2
Kitchen
Cozy #3
Bedroom
Gas Burner
Cozy #1
Living Space
Aqua-Hot
Heating System Cozy #2
Kitchen
Cozy #3
Bedroom
NOTE: The Aqua-Hot Domestic Water System is rated for a
water ow of 0.8 GPM. It is not recommended to modify the
water ow. This can cause an over-pressurized system or
lack of consistent hot water.

Mounting the Aqua-Hot LCDMounting the Aqua-Hot LCD
©Aqua-Hot® 125-GN1 Installation Manual REV 220427 ©Aqua-Hot® 125-GN1 Installation Manual REV 220427 p. 35p. 34
Mounting Considerations:
• Purchase the necessary RV-C connection parts according
to the table below.
• Route the 15’ RV-C cable from the intended mounting
position of the LCD to the Aqua-Hot Controller.
• The LCD screen is powered via the RV-C cable which
connects directly to the Aqua-Hot Controller, or via an on-
board RV-C network.
• “DATA ONLY” RV-C cable congurations are not compatible
with the LCD screen.
• The screen requires at least ¾” (1.9cm) of backside
clearance to allow room for cables and connections.
• Reference Page 38 for more information on the RV-C
Network Connectivity.
Mounting Procedure
1. Select a location within the RV.
2. Cut a 2.50” x 3.64” hole in the RV wall.
3. Route the corners of this cutout with a .35” diameter bit.
4. Using four countersunk #6 screws, secure the LCD bracket
into place over the cutout just made.
5. Connect the RV-C cable to the back of the LCD screen.
Reference Figure 76.
6. Snap the LCD screen into the mounting bracket.
Manufacturer Part Number Common Name
3M 37104-A165-
00E-MB Network Port
General Cable E2104S.41.02 RV-C Communication
Cable
Figure 77
Figure 78
Operating the LCD
Climate Pages:
The climate pages are for all intents and purposes the
“Home” of the LCD screen. From here, the end-user will select
their interior temperature set-points, activate or deactivate the
gas burner and/or the electric element.
Zone Control (1):
Precise zone control display will differ depending on the type
of zone thermostats/thermistors used within the RV.
Section 1A demonstrates the appearance of the zone
control section when ON/OFF thermostats are used within the
RV. In this use-case, these buttons serve only as ON/OFF toggle
switches.
Tapping on one of the zones shown above will display a new
screen where the interior temperature can be set.
Section A:
This section shows the current zone
temperature (shown as 71°F in the example
above) as well as a button to turn the zone
on or off. (Setting specic temperatures can
only be done if thermistors are installed.
Thermostats would only show ON/OFF.)
1
3
45
2
1A
B
C
A
If the zone temperature is set, but this item
is not set to ON, the zone heat exchanger will
not activate.
Section B:
These arrows are used to increase or decrease
the desired set-point temperature of the zone
thermistor.
Section C:
After the desired temperature set-point has
been selected tap “SET” on the LCD to set
that temperature. The Aqua-Hot will now work
to maintain this interior temperature, and the
screen will return home.
External Gas Burner Activation (2):
The external gas burner of the Aqua-Hot can be activated by
tapping on the “burner” item on-screen. The gas burner has two
modes: ON and OFF.
ON:
While set to ON, the Aqua-Hot gas burner will
work to maintain a tank temperature of 180°
F, with a minimum tank temperature of 160° F.
OFF:
While off, the gas burner will not serve to
provide any heat to the boiler of the Aqua-Hot
whatsoever.
Electrical Element Activation (3):
Similar to the external gas burner, tapping this button
will signal to the controller to activate the AC electric relay,
energizing the 1500W electric element within the Aqua-Hot.
The electric heating element has two modes: ON and OFF.
ON:
While set to ON, the electric element will work
to maintain a tank temperature of 180° F,
with a minimum tank temperature of 160° F.
OFF:
While off, the element will not serve to
provide any heat to the boiler of the Aqua-Hot
whatsoever.
NOTE: Please note that the LCD Screen mounting bracket
may only be mounted in this conguration as shown below.
The screen will not t in properly any other way.
2.500”
3.640”
2.455”
3.655”
TOP
Ø 0.150”
(X4)
4.047”
2.843”
Mounting the Aqua-Hot LCD
This following section will explain in detail how to mount the Aqua-Hot LCD on the interior of the RV.
Figure 76
RV-C Connection
3.5” LCD Diagnostic Screen
Operating the LCD & Aqua-Hot
This section will outline the basic operating instructions for the Aqua-Hot LCD Screen.

Conguring the ZonesMounting the Aqua-Hot LCD
©Aqua-Hot® 125-GN1 Installation Manual REV 220427 ©Aqua-Hot® 125-GN1 Installation Manual REV 220427 p. 37p. 36
Operating the LCD
System Status (4):
This item will indicate the current operational status of the
Aqua-Hot. If any faults have triggered, those will be displayed
here.
During normal operation, this should display either INTERIOR
HEAT or HOT WATER relating to the priority and position of the
3-way valve.
While in INTERIOR HEAT mode, the 3-way valve is oriented
so as to circulate heated antifreeze and water solution
through the heating zones of the RV.
While in HOT WATER mode, the 3-way valve is oriented so
that the heated antifreeze and water solution is circulated
immediately back into the boiler tank. This is known as
“stirring” the tank, and it is done to provide as much heat
as possible to the domestic water line while water is owing.
Module Options (5):
Tapping on the module options screen (the 3 lines on
the bottom right of the home screen) will display the screen
shown above. This is known as the Module Options screen.
From here, it is possible to access unit diagnostics, activate
Quiet Mode, change the temperature units, adjust screen
brightness, and unit timeout.
Screen Timeout (A):
The screen timeout item sets the amount of time
required to allow the screen to shut-off when idle.
Screen Brightness (B):
This setting changes the screen brightness.
Unit of Measurement (C):
This setting will change the display units of the Aqua-
Hot. Either Fahrenheit or Celsius can be selected.
Diagnostics (D):
Tapping on this element will direct you to the Aqua-Hot’s
built-in diagnostic, testing, and troubleshooting tools.
Quiet Mode (E):
This option toggles the Aqua-Hot’s quiet mode. Quiet
mode is a setting where the speed and output of the
heat exchanger fans is reduced to 80%. This is done to
reduce noise of the heat exchangers.
Please note that this feature must be activated and
deactivated as needed.
Figure 79
Conguration:
In order to congure these zones for rst use, locate the
Aqua-Hot LCD screen and navigate to the Aqua-Hot Diagnostics
section.
After holding the serial number section above, you will be
presented with an options panel like the one shown below.
Tap OPTIONS, and then CLIMATE ZONES to access the climate
zone conguration sub-menu.
Changing Zone Settings:
Once the Climate Zone section has been accessed, the
information below will explain how to correctly congure the
zones.
Number of Zones (A):
The Aqua-Hot can control between 1 and 3
heating zones within the RV. Modifying this
will set the Controller to manage 1, 2, or 3
heating zones.
Tap and hold 3
seconds anywhere
in this section
A
B
Zone Settings (B):
Zone settings will change the way each zone is
labeled on the home screen of the LCD, as
well as the type of thermostat used in the RV
interior.
Modifying “Temp Input” will change the type of
signal that is expected by the Controller.
• Set to “Thermistor” if an interior thermistor
is to be used.
• Set to “Thermostat” if a traditional ON/
OFF thermostat is to be used.
Modifying “Label” will change how the zone
is displayed. There are three choices; Front,
Mid, and Rear which correspond to the zones
within the RV. See example below.
A
B
C
ED
RV-Side
Connections &
Components Inputs from RV
Outputs to RV Aqua-Hot
Connections &
Components
Inputs from Aqua-Hot
Outputs to Aqua-Hot
Aqua-Hot 3.5in
LCD Screen
Aqua-Hot
Controller
Conguring the Zones
Once the heat exchangers and thermostats have been wired to the Aqua-Hot, the Controller must be congured in order to
correctly manage these zones.