Aqua-Hot 200 Series User manual

Installation Manual
200Series
AHE-250-D01

Introduction
©Aqua-Hot® 250 Diesel Series 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
must be observed.
Contents
Caution Notes ...............................................................................1
Introduction ..................................................................................2
System Features ..........................................................................4
Component Cut-Aways .................................................................5
Installing the 250D ......................................................................6
Support and Clearance ................................................................7
Installation of the Expansion Bottle ............................................9
Heat Exchanger Layout ..............................................................10
Installing Heat Exchangers ........................................................11
Mounting the Heat Exchangers ................................................ 12
Heat Exchanger Locations and Clearances............................. 13
Wiring the Heat Exchangers ......................................................14
Wiring the Zone Thermostats ....................................................14
Plumbing the Heating Zone .......................................................15
Domestic Water System Requirements ....................................17
Plumbing the Domestic Water System .....................................17
Interior Switch Panel ................................................................. 18
Diesel Fuel System .................................................................... 20
Exhaust System ......................................................................... 23
Pin-Out Information ................................................................... 26
Connecting the 250D to 12V DC Power ...................................27
Connecting the Aqua-Hot to AC Power ..................................... 28
Filling/Purging the Aqua-Hot 250D .......................................... 29
First Operation ........................................................................... 30
Winterizing ..................................................................................31
Appendix A: System Schematics .............................................. 32
Appendix B: Measuring Antifreeze ........................................... 33
Appendix C: Parts & Accessories ............................................. 36
Warranty .................................................................................... 43

Introduction
©Aqua-Hot® 250 Diesel Series Installation Manual p. 2
WHAT TO DO IF YOU SMELL GAS
• Evacuate all persons from the vehicle.
• Shut off the gas supply as the gas container or source.
• Do not touch any electrical switch or use any phone or radio
in the vehicle.
• Do not start the engine or electric generator (if equipped).
• Contact the nearest gas supplier or qualifi ed service
technician for repairs.
• If you cannot contact the nearest gas supplier or qualifi ed
service technician, contact the nearest fi re department.
• Do not turn on the gas supply until the gas leak or leaks (if
relevant) have been repaired.
• Installation and service must be performed by a qualifi ed
installer, service agency, or gas supplier.
The Aqua-Hot’s exhaust is HOT!
• Do NOT park in areas where dry conditions exist (IE grassy,
dry fi elds).
• Do NOT operate the burner inside an enclosed building.
• The heater must be switched OFF when refueling.
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.
• The Aqua-Hot must be installed in a compartment that is
closed off from living quarters and accessible only from the
exterior of the vehicle.
• Propylene glycol based antifreeze “Generally Recognized
As Safe” (GRAS) by the FDA must be utilized for the
antifreeze and water heating solution.
• An interlock switch prevents the Aqua-Hot heater from
operating when the cover is not installed in the correct
position.
• 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 fuel system.
• Do not store or use gasoline or other fl ammable vapors or
liquids in the vicinity of this or any other appliance.
• The Aqua-Hot’s exhaust is HOT and must be kept away from
heat sensitive material.
• 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.
• Do NOT activate the burner until the antifreeze and water
heating solution has been added to the boiler tank to avoid
serious damage to the heater.
• 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.
If the information in this manual is not followed exactly,
a fi re or explosion may result, causing property damage,
personal injury or death.
NOTE: Should any additional assistance be needed, please
contact the Technical Support Department at 574-AIR-XCEL
(574-247-9235).

Introduction
©Aqua-Hot® 250 Diesel Series Installation Manual p. 3
About the Aqua-Hot 200 Series
The Aqua-Hot 250 Diesel Series Hydronic (water-based)
heating systems provide interior heat and tank-less continuous
hot water in one small, easy to install package.
The heating system provides moist, quiet, comfortable
interior heat. The Aqua-Hot is equipped with one thermostatically
controlled temperature zone.
The tank-less hot water system produces 90 gallons per
hour (1.5 GPM) of continuous hot water.
These TribridHot™ Systems use 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 heater also employs a 12V DC diesel burner as the
primary heating source. The burner should be used for
continuous hot water and interior heating in cold conditions.
In addition to the burner, the 250D Series model also employs
an electric heating element as a heating source.
Once the tank has reached temperature by way of the 12V DC
diesel burner, the electric element may be engaged to provide
light-duty hot water and heating needs, and serves to maintain
tank temperature during periods which the heater is not in
used. For continuous hot water and heat in cold conditions, the
diesel burner must be active.
Should additional assistance be needed, please contact
the Product Application Department at 574-AIR-XCEL (574-247-
9235) Monday through Friday, 7am to 4pm Mountain Standard
Time.
System Overview
The Aqua-Hot 250 Diesel Series is a Hydronic Heating
System that can provide heat and hot water on demand using a
built-in electric heating element and a diesel 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 fl ow of continuous
hot water.
The Aqua-Hot heating system heats an propylene glycol
based antifreeze and distilled water solution that is stored in
the Aqua-Hot’s boiler tank. This fl 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 1.5 GPM of hot water.

System Features
©Aqua-Hot® 250 Diesel Series Installation Manual p. 4
System Specifi cations
Electric Element
Power Consumption ......................................1000 W (maximum)
Voltage ..............................................................................120V AC
DC Power
Heat Input ..................................................66,000 BTU/hr ± 10%
Fuel Consumption ..................................................0.40 gallon/hr
Power Consumption ......................................... 108W (maximum)
Zone Heat Circulation
Pumps ...........................................................................................1
Power Consumption (max) ..................................................... 21W
Voltage ............................................................................... 12V DC
Heating Zones
Maximum ......................................................................................1
Domestic Water Heating
Maximum ......................................................................... 1.5 GPM
Physical Specifi cations
Dimensions (US).............................17.2”H x 12.46”W x 22.44”L
Dry Weight ........................................................................... 84lbs.
Wet Weight ......................................................................... 104lbs.
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.
Figure 1
NOTE: This product label is attached to the side of the
Aqua-Hot, and provides a ready reference to specifi cations,
test standards, and important safety notices.

Component Cut-Aways
©Aqua-Hot® 250 Diesel Series Installation Manual p. 5
NOTE: The side and top panels in the view below have been
made transparent 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 panel for service.
89
5
4
3
2
1
15
16
6
7
17
18
10
1. Access Cover Screw
2. Drain Valve
3. 3-Way Valve
4. Tempering Valve
5. Diesel Burner Controller
6. Diesel Burner Assembly
7. Interlock Switch
8. Domestic Cold Water Inlet
9. Domestic Hot Water Outlet
10. 12V DC Harness Junction
11. Diesel Fuel Connections
12. Expansion Tank Connection
13. Heating Zone Return Port
14. Heating Zone Outlet Port
15. 120V AC Connection
16. Boiler Tank
17. Domestic Hot-Water Coil
18. Zone Circulation Pump
Figure 2
11 12 13 14

Support and Clearance
©Aqua-Hot® 250 Diesel Series Installation Manual p. 6
Installing the 250D
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. The Aqua-Hot must be installed in a compartment
that is completely closed off from living quarters and accessible
only from the exterior.
1. Reference the following illustrations below for mounting
information.
2. Cut out the required mounting fl ange opening Reference
Figure 4.
3. Install the fl ange located on the bottom of the Aqua-Hot into
the cutout opening. Reference Figure 6 & 7.
4. Take the angle brackets and included ¼-20 bolts and
washers. Install the angle brackets into the nuts located
on the fl anges.
• Front view Aqua-Hot dimensions Figure 3.
• Floor cutout information Figure 4.
• ID Label noting the front and service access
clearance requirements Page 4.
Figure 3
NOTE: Inspect the area beneath the mounting location to
ensure that no structural members will interfere with the
cutout for the mounting fl ange. Verify that a support structure
of adequate strength has been constructed. Figure 5.
15.2”
17.2”
2.94” 7.55” 1.97”
Aqua-Hot Installation

Support and Clearance
©Aqua-Hot® 250 Diesel Series Installation Manual p. 7
Figure 5
Cross-Member
Supports
NOTE: The mounting fl ange of the Aqua-Hot is not centered
on the body of the heater. Reference Figure 4 for the correct
dimensions to construct the surface on which the Aqua-Hot
will be mounted.
Additional cross-members are required if the existing
structure is unable to support 104lbs.
Figure 4
Minimum Clearance
on all sides is 1”.
22.44”
7.675” 2”
12.625”
2”
12.57”
9.815”

Support and Clearance
©Aqua-Hot® 250 Diesel Series Installation Manual p. 8
Seat the Aqua-Hot in
the Flange cutout
Coach Bay Floor
¼-20 Bolt and
Lock Washer
Mounting Brackets on both
sides, front, and rear
NOTE: Angle mounting bracket must be fl ush to the
underside of the coach fl oor and fl ush to the heater fl ange.
Tighten bolts to roughly 76 in-lbs.
Heater Flange
Mounting Bracket
¼-20 Bolt and
Lock Washer
Figure 6
Figure 7

Fluid Expansion Bottle
©Aqua-Hot® 250 Diesel Series Installation Manual p. 9
Installation of the Expansion Bottle
Introduction:
The fl uid expansion bottle 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 bottle.
Installation Procedure:
1. Select a mounting location that allows for easy access and
clear visibility whenever the storage bay containing the
expansion bottle is open.
2. Mount the expansion tank as illustrated in Figure 10.
3. Connect and clamp the overfl ow tubing from the expansion
tank to the Aqua-Hot’s expansion tank connection.
4. Drill a hole in the bay fl oor and cut a piece of overfl ow
tubing (included with unit) of adequate length so that it can
be connected to the top of the expansion tank and extend
through the bay fl oor. The expansion hose should vent to
the exterior of the Aqua-Hot bay.
5. Locate the wire leads exiting the expansion bottle.
6. Connect these wires to wires #10, #15, and #16 on the
Aqua-Hot wiring harness. Note that wires #10 and #15 will
co-terminate in a single jacketed connector as shown in
Figure 9.
7. Once complete, secure these wire leads to minimize risk of
accidental damage.
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 bottle.
Hot Fluid Line
Cold Fluid Line
Fluid Level Sensor
Fill Cap
Lower Fitting
Upper Fitting
Figure 8
Figure 9
Expansion hose
Fluid Level Sensor Wiring Connections
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 10
Hole in the coach bay
fl oor for overfl ow hose
Lower fi tting of the
expansion bottle must
not extend below this
line.
Tension Clamps
#15
#10
#16

Fluid Expansion Bottle
©Aqua-Hot® 250 Diesel Series Installation Manual p. 10
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.
Heat Exchanger Layout
Aqua-Hot Unit
Cab
Living Area
Bathroom
Bedroom
Heat Exchanger 1
Heat Exchanger 2
Heat Exchanger 3
Heat Exchanger 5
Heat Exchanger 4
NOTE: The fi fth heat exchanger should be placed in the
bathroom, as it is typically the smallest area and therefore
requires the least amount of heat volume to maintain
temperature.
Figure 11

Installing Heat Exchangers
©Aqua-Hot® 250 Diesel Series Installation Manual p. 11
Installation Requirements
Cozy heat exchangers can be mounted in one of two
confi gurations: either fl at on the ground, or vertically. Reference
Figure 12.
• 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 fl ow in
through the bottom of the heat exchanger, and out the top
(reference Figure 23).
Vertical Orientation
Horizontal Orientation
Figure 12
Figure 13
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

Installing Heat Exchangers
©Aqua-Hot® 250 Diesel Series Installation Manual p. 12
Mounting the Heat Exchangers
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 15.
2. Mount each heat exchanger permanently into place. There
are 4 tabs on both sides - see Figure 23.
3. Install the hot-air outlet and cold-air return grate. Figure 15.
A minimum of supply ventilation cross-sectional area of at
least 29in2 (74cm2) must be supplied to each heat exchanger.
Please note that a return-air register may not be required,
however, adequate return air must be provided to the heat
exchanger or you may experience diminished performance of
the heat exchanger unit.
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. The plenum allows only the desired
outlets to be opened by removing the metal insert on the vent.
Refer to Figure 14 & 16.
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 15
Figure 14
Figure 16

Locations and Clearances
©Aqua-Hot® 250 Diesel Series Installation Manual p. 13
Heat Exchanger Locations and
Clearances
• Position the heat exchangers so that even heat is distributed
throughout the coach interior. Reference Page 10.
• 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.
• 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.
• The heating air supply may be fresh or recirculated air that
is drawn from a clean area not likely to be contaminated.
Boost Pump
If desired, a 6th Cozy Heat Exchanger may be added to the
heating loop within your coach. Please note, however, that an
additional boost pump is required to provide adequate fl uid
pressure to allow the 6th heat exchanger to operate as intended.
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 17
Figure 18
NOTE: For single slide-out confi gurations, it is usually
simplest to place a heat exchanger on the opposite side of
the coach pointing towards the slide-out.
Figure 19

Wiring Heat Exchangers
©Aqua-Hot® 250 Diesel Series Installation Manual p. 14
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 parallel circuit inside the
coach (all heat exchangers share a common power wire
and a common ground wire) as shown in Figure 21.
2. Run the power wire from the last heat exchanger back to
the 8-pin connector and plug it into Pin #7.
3. Run the ground wire from the last heat exchanger back into
the 8-pin connector and plug it into Pin #8.
4. With the remaining heat exchangers, tap the power from
each exchanger into the previously connected power wire
that is running back to the 8-pin connector.
5. Repeat Step 4 with the ground wire.
Figure 21
12V DC Power (Pin 7)
Ground (Pin 8)
Wiring for OEM RV-C or Multiplex
Control Systems
When choosing a zone control for the heat exchangers, the
following guidelines must be adhered to, or the Aqua-Hot will
not function correctly in any mode of operation.
• Pin 6 must be supplied with +12V DC to provide power
to the coolant circulation pump.
• Pin 7 must be integrated into the OEM control of the
zone.
• Pin 7 will be +12V DC when there is a call for interior
heat. This +12V DC current will drop when the Aqua-Hot
senses domestic water fl ow.
Figure 20
Diesel Harness Plug
Wire insertion view shown

Wiring Heat Exchangers
©Aqua-Hot® 250 Diesel Series Installation Manual p. 15
Heat Exchanger Install
Plumbing the Heating Zone
The following guidelines should be used when planning
the coolant loop for the heating 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 fl 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.
• When exceeding 5 heat exchangers, a boost pump must be
installed in the coolant line to provide adequate pressure
to ensure that coolant is distributed throughout the heating
loop. See Figure 19.
• 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.
Instructions:
1. Layout the plumbing lines for all heat exchangers (see the
example in Figure 24).
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 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.
Mounting
Tabs (both
sides)
Inlet
Outlet
Figure 23
NOTE: The diagram below is simply a reference to show the
layout and fl ow of the plumbing to and from heat exchangers.
Placement and quantity may vary depending on the coach.
Figure 24
Inlet
Outlet
PEX Insert Hose
Clamps ¾”
Coupler
Figure 22
Cozy #1
Cozy #2
Cozy #3
Cozy #5
Cozy #4
Aqua-Hot
Heating System

Wiring Heat Exchangers
©Aqua-Hot® 250 Diesel Series Installation Manual p. 16
Heat Exchanger Install
NOTE: The AC relay enclosure has been hidden in these views
to allow an unobstructed view of the constant tension clamps.
Figure 25
Figure 26

Domestic Water System
©Aqua-Hot® 250 Diesel Series Installation Manual p. 17
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 27.
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 diesel 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 modifi 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.
To Hot Water
Faucets
Tempered
Domestic Hot Water
Fresh Water
Storage Tank
To Cold Water
Faucets
Demand Pump
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.
Figure 27

Domestic Water System
©Aqua-Hot® 250 Diesel Series Installation Manual p. 18
Interior Switch Panel
Select a location in the interior of the coach that allows for
easy operator access. The switch panel should be installed in
a central location inside the coach that is easily accessible to
turn the system on and off. Mounting plate dimensions for the
panel are shown below.
Coach Control Panel Screen:
Newer Aqua-Hot units may have a coach touch-screen
display instead of the interior switch panel. This section is only
for the installation and wiring for the interior switch panel.
All electrical installations, systems, and equipment shall
comply with Article 551, Parts I through VI of NFPA 70, as well
as the regulation of authorities having jurisdiction and CSA
Standard B139.
Switch Panel Mounting
1. Cut out a 3.75” W x 1.25” H opening for the switch
panel plate. Reference Figure 28.
2. Once the switch panel has been completely wired,
permanently mount the switch panel in place.
3. Using four countersunk 3mm (#4) screws, secure the
switch plate into place over the cutout just made.
4. Move both switches to the OFF position by pressing
them in a downward motion.
Switch Panel Wiring
1. Run 16-gauge wires from the switch panel to the 8-way
connector to the Aqua-Hot.
2. Strip and crimp insulated female terminals onto each
wire at the switch panel location.
3. Connect all switch wires to the appropriate switch
connections. Reference the following diagram and the
schematic on Page 32.
4. Run the wires from the switch to Pins #3 and #4 on the
8-way connector at the Aqua-Hot.
NOTE: Be sure to attach “Jumper Wires” where
necessary. Reference the following switch diagrams.
Switch Panel Installation
5.00”
4.45”
2.88” 2.33”
Ø 0.15”
(x4)
1.20”
0.871”
.275”
Figure 28

Domestic Water System
©Aqua-Hot® 250 Diesel Series Installation Manual p. 19
AC Electric
Switch
12-Pin Mate-N-
Lock
Burner Switch 12-Pin Mate-N-
Lock
#4 #9 #4 #3
#2 #10 #2 #4
#9 Chassis Ground #9 Chassis Ground
#10 #11
Wire Insertion View Shown
Figure 30
NOTE: The Electric Element switch
must possess a jumper wire between
Pin 4 and Pin 10 as depicted.
Electric Burner
10
2
4
9 10
2
4
9
Figure 29
Jumper Pins
(see note)
Manufacturer Part No. Description
TE Connectivity 1-480709-0 Mate-N-Lock
Receptacle Housing Information
Switch Panel Rear View
250-D01 Switch Panel