Aqua-Hot 400-LP User manual

INSTALLATION MANUAL
400SERIES
400-LP

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Introduction & Cautions
About the Aqua-Hot 400-LP
The Aqua-Hot 4OOLP is a hydronic (water based) heating
system, and tank-less hot water system.
The heating system provides moist, quiet, comfortable,
interior heat. It is equipped with up to five separate thermo-
statically-controlled temperature zones and prevents tank
and line freezing in the bays.
The tank-less hot water system produces 90 gallons per
hour of continuous, on-demand, hot water.
This TribridHot™ designated system uses one or a combi-
nation of heat sources to heat FDA-approved “Generally Rec-
ognized as Safe” (GRAS) propylene glycol based antifreeze
solution in the Aqua-Hot’s boiler tank.
The 400LP uses one 120 Volt-AC, 1650 Watt electric
element to heat the system when shore power is available,
and a 12 Volt-DC powered propane burner when dry camp-
ing. The heat sources can be used separately or together.
Should additional assistance be needed, please contact
the Product Application Department at 1-800-685-4298,
Monday through Friday, between the hours of 7 a.m. and 4
p.m. Mountain Time.
As you read this Information, take particular note
of the NOTICE, CAUTION, WARNING and
DANGER symbols when they appear. This infor-
mation is important for safe and efficient use of
the Aqua-Hot equipment.
NOTICE signals a situation where potential dam-
age to the equipment 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 you do not follow instructions.
DANGER signals a situation where immediate risk
of serious injury or death will result if you do not
follow instructions.
NOTE In addition, this manual may indicate an
IMPORTANT NOTE that highlights information that
is especially important.
Caution Notes

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Contents
Aqua-Hot 400-LP Installation Manual
Introduction & Cautions ................................................ 3
Section 1: Aqua-Hot Hydronic Heating System
Safety Instructions & Precautions ................................ 5
Heating System Features .............................................. 6
Cut-Away Diagrams........................................................ 7
Section 2: Aqua-Hot Installation
Installing the Mounting Tray and Aqua-Hot .................. 8
Installing the Expansion Tank ....................................... 8
Pressure Testing the Aqua-Hot ..................................... 8
Aqua-Hot Measurement diagrams...........................9-12
Section 3: Hydronic Heating System
Heat Exchanger Location and Clearances .................13
Heat Exchanger Mounting Requirements ..................13
Heat Exchanger Floor Plan ..........................................14
Mounting the Heat Exchangers...................................15
Heat Exchanger Measurement diagrams...................16
Wiring the Heat Exchanger.................................... 17-18
Plumbing Requirements..............................................19
Plumbing the Hydronic Heating System ............... 20-22
Section 4: Thermostats
Fresh Water Tank Thermostat Locations ...................23
Fresh Water Tank Thermostat Mounting....................23
Positioning the Bulb and Capillary Tube.....................23
Setting the Temperature .............................................23
Fresh Water Tank Thermostat Wiring .........................23
Room Thermostat Locations .......................................24
Room Thermostat Mounting .......................................24
Room Thermostat Wiring.............................................24
Section 5: Domestic Water System
Domestic Water System Requirements .....................25
Domestic Water System Plumbing ....................... 25-26
Section 6: Switch Panel
Switch Panel Location .................................................27
Switch Panel Mounting................................................27
Switch Panel Wiring .....................................................27
Switch Panel Rear View ...............................................28
Index
Section 7: Fuel System
Fuel System Requirements......................................... 29
Fuel System Installation.............................................. 29
Section 8: Exhaust System
Exhaust System Requirements................................... 30
Installing the Exhaust System............................... 30-32
Section 9: Electronic Controller Wiring
Electronic Controller Wiring .................................. 33-34
Wiring Harness Connection......................................... 34
Connecting the 12V DC Power.................................... 35
Connecting the 120V AC Power.................................. 35
Section 10: Purging the System
Purging the Hydronic Heating System ........................ 36
Purging the System by Grounding the Zone............... 37
Purging the Domestic Water System.................... 37-38
Safety Instructions & Precautions .............................. 39
Purging the Propane System ...................................... 40
Section 11: Initial Start-up
Activating the Aqua-Hot.............................................. 40
Appendices
Appendix A: Wiring Diagram........................................ 41
Appendix B: Wire Gauge Information ......................... 42
Appendix C: Electronic Controller Features.......... 43-44
Appendix D: Antifreeze Types...................................... 45
Appendix E: Antifreeze Mixture Quality....................... 45
Appendix F: Antifreeze Terms & Mixture Ratio .... 46-47
Appendix G: Measuring Antifreeze Refractometer48-49

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Safety Instructions & Precautions
The Unit
IMPORTANT NOTE: Read all instructions before installing
this appliance.
 Read this Installation Manual before installing or using
the Aqua-Hot System to reduce the risk of injury to per-
sons or damage to equipment.
 The product identity label contains specifications of the
unit, to what standard it has been tested, and im-
portant safety notices.
 The Aqua-Hot must be installed in a compartment that
is closed off from living quarters and accessible only
from outdoors.
 Propylene glycol based antifreeze “Generally Recog-
nized as Safe” by the FDA must be utilized for anti-
freeze and water heating solution.
 An interlock switch prevents the Aqua-Hot heater from
operating when the cover is not installed in the correct
position.
 Should any additional assistance be needed, please
contact the Product Application Department at 800-
685-4298 or 303-651-5500.
 Disconnect electric wiring to the Aqua-Hot System be-
fore welding or plasma cutting the coach to avoid dam-
age to equipment.
 Air pressure to the tank must not exceed 20 PSI or will
cause internal damage.
 The Aqua-Hot’s exhaust is HOT and must be kept away
from heat sensitive material.
 Use caution when working on or near the propane gas
system.
 DO NOT connect the 12 Volt-DC power to the Aqua-Hot
if the vehicle requires welding.
 At maximum operating temperatures, the coolant will
be very hot and scalding hot vapor or coolant may re-
sult in serious burns or injury.
 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.
If this information in these instructions is not followed
exactly, a fire or explosion may result causing property
damage, personal injury, or death.
 Do not store or use gasoline or other flammable va-
pors and liquids in the vicinity of this or any other ap-
pliance.
WHAT TO DO IF YOU SMELL GAS
 Evacuate all persons from the vehicle.
 Shut off the gas supply at the gas container or source.
 Do not touch any electrical switch or use any phone or
radio in the vehicle.
 Do not start the vehicle’s engine or electric generator.
 Contact the nearest gas supplier or qualified service
technician for repairs.
 If you cannot reach a gas supplier or qualified service
technician, contact the nearest fire department.
 Do not turn on the gas supply until the gas leak(s) has
been repaired.
 Installation and service must be performed by a quali-
fied installer, service agency, or gas supplier.

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400-LP Features
The product label
attached to each
Aqua-Hot provides
a ready reference
to specifications,
test standards, and
important safety
notices.
NOTICE
Propane Burner
Heat Input (Firing Rate) 51,663 BTU/h
Fuel Consumption (Continuous) 0.72 g/h
Electric Heating Element
Specifications 120 VAC/1650 W
Voltage/Maximum Power Consumption 12 VDC/60 W
Zone Heat Circulation
Pumps 2
Voltage/Maximum Power Consumption 12VDC/21 W
Heating Zones
Maximum 5
Domestic Water Heating
Capacity with continuous supply On-Demand
Specifications
Dimensions 12”H x 18.5”W x 29.5”L
Dry Weight 127 lbs.
Wet Weight 184 lbs.
All vehicle installations must comply with the requirements listed in the
Recreational Vehicle Industry Association’s (RVIA) ANSI/NFPA 1192
Handbook for Recreational Vehicle Standards. To receive a copy of this
handbook and other pertinent RVIA Standards, write to: Recreation
Vehicle Industry Association, 1896 Preston White Drive, P.O. Box 2999,
Reston, VA 22090-0999, call them at [phone], or online at
www.rvia.org, www.nfpa.org.
Aqua-Hot Heating System Features

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1
2
6
7
11
13 14
16
18 20
1
2
6
7
11
13 14
16
18 20
4
3 58
9
10
12
15
17
1921
NOTE: Service parts and accessories are available
through Aqua-Hot Factory Authorized Service Center or
at www.aquahot.com.
1. AC Terminal Block
2. AC Terminal Port
3. AC Wiring Port
4. Access Cover
5. Air Release Valve
6. Propane Burner
7. Propane Burner Controller
8. Propane Fuel Inlet/Outlet Ports
9. Domestic Cold Water Inlet
10. Domestic Hot Water Outlet
11. Drain Valve
12. Expansion Tank Connection
13. Heating Zone 1 Outlet Port
14. Heating Zone 2 Outlet Port
15. Tempering Valve
16. VAC Access Panel
17. Wiring and Harness Port
18. Zone 1 Circulation Pump
19. Zone 1 Inlet Port
20. Zone 2 Circulation Pump
21. Zone 2 Inlet Port
Aqua-Hot Heating System Features
Cut-Away Diagrams

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Aqua-Hot Installation
Installing the Mounting Tray and the
The Aqua-Hot must be installed in a compartment that is
completely closed off from living quarter and accessible only
from the outdoors.
1. Reference the following illustrations for mounting infor-
mation:
2. Cut out the required mounting tray opening. Reference
Figure 2.
3. Install the mounting tray flange into the cut-out opening.
Reference Figures 2 and 3.
4. Insert a #10 machine screw into each of the embossed
holes in the mounting tray (total of six required) and
tighten to secure the mounting tray to the motorhome.
5. Place the Aqua-Hot into the mounting tray. Reference
Figure 3.
NOTE: Be sure to complete the following when installing the
Aqua-Hot
Inspect the area beneath the mounting location to ensure
that no structural members will interfere with the cut-out for
the mounting tray.
Verify than an adequate support system, has been provided
for the Aqua-Hot.
NOTE: Secure the mounting try into place prior to installing
the Aqua-Hot.
Remove the access cover fastener from the Aqua-Hot prior
to the installation of the Aqua-Hot into the mounting tray.
Mount the Aqua-Hot securely into the mounting tray to en-
sure that the unit does not move or shift under normal oper-
ating conditions.
NOTE: Remove the bolt securing the front of the access cov-
er to the mounting tray. This bolt will need to be reinstalled
once the total installation procedure is complete. Remove
the access cover.
- Overall Aqua-Hot dimensions. Reference Figure 1.
- Mounting Tray Information. Reference Figure 2.
- I.D. Label noting the “Open Access” clearance
requirement for the front of the heater. Reference
Figure 5.
- Service Access Clearance. Reference Figure 5.
Installing the Expansion Tank
Select a mounting location that allows for easy access
and clear visibility whenever the particular storage bay door
is open.
NOTE: The top of the expansion tank should always be
mounted at least 4 inches higher than the highest point on
the Aqua-Hot. Reference Figure 4.
1. Mount the expansion tank as illustrated in Figure 4.
2. Connect and clamp the overflow tubing from the expan-
sion tank to the Aqua-Hot’s expansion tank connection.
Reference Figure 4.
3. Drill a hole in the bay floor and connect (secure with a
clamp) a long piece of overflow tubing so that it can be
connected to the top of the expansion tank and extend
through the bay floor.
NOTE: Avoid any dips and bends in the overflow tubing from
the Aqua-Hot to the expansion tank as air can become
trapped in these dips and bends. This will prevent the ex-
pansion of the heating solution from properly depositing in
the expansion tank.
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.
Pressure Testing the Aqua-Hot:

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Aqua-Hot Installation
— Page 9 —
Figure 1

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Aqua-Hot Installation
Figure 2

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Aqua-Hot Installation
Figure 3

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Aqua-Hot Installation
Figure 4
400LP
Figure 5
1/2 in.
1/2 in.
1 in.

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Hydronic Heating System
Heat Exchanger Locations and
Clearances
Place the heat exchangers so that even heat distribution
will be felt throughout the interior of the motor home. Refer-
ence Figure 7A.
Place the heat exchangers where they will be accessible
for potential servicing and cleaning.
Centralize and position a heat exchanger in the fresh
water storage tank plumbing bay. Reference Figure 5.
Reference Figures 6, 7A, 7B, and 8, for mounting loca-
tion information.
Reference Figure 6 for clearance information.
NOTE: An accessory device is available for the Cozy
Heat Exchanger for the purpose of redirecting the air-
flow from the heat exchanger. Reference Figures 9 and
10.
Figure 5
Mounting Requirements
Sufficient ventilation (return-air) must be supplied to
each interior heat exchanger. Reference Figure 8.
Figure 6
NOTE: In order to achieve the nest heating results, place
the heat exchanger as close to the floor of the plumbing
bay as possible (heat will naturally rise).
NOTE: For single slide-out configurations, it is usually sim-
plest to place a heat exchanger on the opposite side of the
motor home pointing towards the slide-out.
NOTE: Ventilation (return air) must be supplied from the
living area. Ventilation (return air) MAY NOT be supplied
from the bay area.
NOTE: Mounting the heat exchangers without sufficient
ventilation will severely reduce their overall heating perfor-
mance (heat output).
In order to provide sufficient ventilation, the return air reg-
isters must be the same size, or larger than the outlet-
register,
Return-air must be supplied from the corresponding interi-
or heating zones.

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Hydronic Heating System
Figure 7A
Generalized Motorhome Heating System Floor Plan
Figure 7B
Indicates sample mounting locations for
the Cozy heat exchangers. Actual place-
ment and quantity vary based on the
individual design of the coach. For spe-
cific design assistance, contact Aqua-Hot
at (303)-651-5500

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Hydronic Heating System
Mounting the Heat Exchangers
If the toe-kick areas in the motor home are inadequate
to house a heat exchanger for regular installation, a plenum
may be used on the heat exchanger, which can be used
with a smaller vent as seen in Figure 10. The plenum allows
only the desired outlets to be opened by removing the metal
insert on the vent.
Figure 10
1. Hose to direct air to vent
2. Cozy Heat Exchanger
3. Plenum
4. Vent Installed In Toe-Kick area
5. Toe Kick Board
1
2
3
4
5
1. Cut out a 2.5 inch H x 10 inch W opening for each heat
exchanger outlet and cold-air return register. Reference
Figure 21.
2. Mount each heat exchanger permanently into place.
Reference Figures 11 and 12.
3. Install the hot-air outlet and cold-air return registers.
Reference Figure 8.
Figure 8
Figure 9
NOTE: Please note that a return-air register may not be re-
quired; however, adequate return-air must be provided to
each particular heat exchanger. This means that the total
cross-sectional area of the return-air opening must be
equal to or greater then the cross-sectional area of the hot-
air outlet opening of the heat exchanger.

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Hydronic Heating System
Figure 11
Figure 12

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Hydronic Heating System
Wiring the Heat Exchangers
1. Run two 18-gauge wires, red for (+) and black for (-),
from each particular heating zone’s heat exchanger to
the electronic controller. Reference Figure 14.
2. Label the wires indicating the heating zone they pertain
to (e.g., Living Room, Bathroom, Bedroom, etc.)
3. Insert all heat exchanger wires into the appropriate ter-
minal/heating zone location on the electronic controller.
Reference Figure 13 and Appendix
A.
4. Wire all heat exchangers in a zone in-series. Reference
Figure 14 and Appendix A.
5. Connect all electronic controller wires to the positive
and negative leads of the heat exchanger. Reference
Figures 14 and 15.
Figure 13

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Hydronic Heating System
Figure 14
Figure 15
When wiring the heat exchanger in-
parallel, the main 18-gauge wire is
split to allow the heat exchanger
wires to combine with the main wire
to be powered or grounded, respec-
tively.

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Hydronic Heating System
Plumbing Requirements
Once all heat exchangers have been mounted, formulate
a plan for the routing of the plumbing lines from each heat-
ing zone to the Aqua-Hot.
All plumbing lines should be laid as flat as possible, and
any extreme rises in height should be avoided to eliminate
any potential air-traps.
The kitchen and living room heat exchangers (typically
three) must be plumbed together in-series on “Heating Loop
1.” Reference Figure 16.
The fresh water tank, bedroom, and bathroom heat ex-
changers (typically 3) must be plumbed together in-series
on “Heating Loop 2.” Reference Figure 16.
Use 5/8 inch I.D. (Inside Diameter) plumbing lines for
both heating loops.
Use wide-sweeping elbows or “bend supports” whenever
the plumbing lines may be susceptible to kinking (i.e., 90°
bends).
Figure 16
NOTE: When exceeding 3 heat exchangers or for longer
coolant line lengths a boost pump in the coolant system
may be required

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Hydronic Heating System
Plumbing the Hydronic Heating System
Figure 17
1. Lay out the plumbing lines for all heat exchangers.
2. Label each line with the heating loop number and desig-
nate as an inlet or an outlet line.
3. Connect and clamp the outlet line from the heater to
the lowest port on the heat exchanger with the longest
run, for both heating loops. Reference Figure 17. Then,
connect each additional heat exchanger in the same
arrangement (low to high).
NOTE: Run all the plumbing lines in areas where they can-
not be pinched off or damaged under normal operating
conditions.
Be sure to secure all lines where necessary and apply pro-
tective shielding in areas where chafing may occur.
Rubber Coated/Closed-Type clamps are recommended
when securing the plumbing lines.
4. Connect and clamp the inlet line from the heater to the
highest port on the last heat exchanger for both heating
loops. Reference Figure 17.
5. Connect and tighten all interior plumbing lines, outlet
and inlet, to the Aqua-Hot’s appropriate heating loop
ports. Reference Figure 19 and Figure 20.
NOTE: Reference Figure 18 for visual instructions on con-
necting the PEX-Type tubing to each heat exchanger.
Plumbing heat exchangers in this manner will allow air to
escape naturally. If air is trapped in any heat exchanger, it
will significantly reduce the heat exchanger’s overall heat-
ing performance (heat output).
NOTE: The inlet and outlet plumbing lines can be installed
with a straight fitting or an elbow fitting.