Aqua-Hot 675-D User manual

© 2011 Aqua-Hot Heating Systems Inc.
INSTALLATION MANUAL

CAUTION:
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.
CAUTION:
Before welding or plasma cutting on any coach;
it is necessary to disconnect the electric wiring to
the Aqua-Hot System.
Failure to disconnect the wires from the
Aqua-Hot System before using a welder or a
plasma cutter on the coach may cause damage to
the Aqua-Hot.

© 2011 Aqua-Hot®675-D Installation Manual
TABLE OF CONTENTS
Aqua-Hot 675-D Installation Manual
Introduction...........................................................................................................................................5
Section 1: Aqua-Hot Hydronic Heating System
Technical Information..........................................................................................................................6
Section 2: Aqua-Hot Installation
Installing the Mounting Tray and the Aqua-Hot..............................................................................10
Overall Aqua-Hot Dimensions...........................................................................................................11
Installing the Expansion Tank............................................................................................................14
Section 3: Hydronic Heating System
Heat Exchanger Location and Clearances.........................................................................................15
Heat Exchanger Mounting Requirements.........................................................................................15
Mounting the Heat Exchangers..........................................................................................................16
Sample Heating System Floorplan......................................................................................................16
Wiring the Heat Exchangers ...............................................................................................................19
Plumbing Requirements.......................................................................................................................22
Plumbing the Hydronic Heating System...........................................................................................22
Section 4: Thermostats
Fresh Water Tank Thermostat............................................................................................................25
Room Thermostats...............................................................................................................................26
Section 5: Domestic Water System
Domestic Water System Requirements .............................................................................................27
Domestic Water System Plumbing.....................................................................................................27
Section 6: Switch Panel
Switch Panel Location..........................................................................................................................29
Switch Panel Mounting........................................................................................................................29
Switch Panel Wiring..............................................................................................................................29
Section 7: Fuel System
Fuel Filter Location ..............................................................................................................................31
Fuel System Requirements...................................................................................................................31
Fuel System Installation.......................................................................................................................31

Section 8: Engine Preheat and Motoraide System
Engine Preheat System Location........................................................................................................34
Engine Preheat Plumbing Requirements...........................................................................................34
Engine Preheat Plumbing Installation ...............................................................................................34
Section 9: Exhaust System
Exhaust System Requirements............................................................................................................36
Installing the Exhaust System .............................................................................................................36
Section 10: Electronic Controller Wiring
Electronic Controller Wiring……………………………………………………………...40
Wiring Harness Connection………………………………………………………………41
Connecting the 12 Volt-DC Power……………………………………………………….42
Section 11: Purging the Systems
Purging the Hydronic Heating System...............................................................................................43
Purging the System by Grounding the Zone Thermostat Connection.........................................44
Purging the Domestic Water System..................................................................................................44
Section 12: Initial Start-Up
Activating the Aqua-Hot......................................................................................................................46
Appendices:
Appendix A: Wiring Diagram .............................................................................................................47
Appendix B: Wire Gauge Information..............................................................................................48
Appendix C: Electronic Controller Features ....................................................................................49
Appendix D: Antifreeze Types ...........................................................................................................51
Appendix E: Antifreeze Mixture Water Quality Recommendations.............................................51
Appendix F: Antifreeze Terms and Mixture Ratio ..........................................................................52
Appendix G: Measuring Propylene Glycol Using a Refractometer...............................................52
TABLE OF CONTENTS (CONTINUED)

© 2011 Aqua-Hot®675-D Installation Manual
INTRODUCTION
Danger, Warning, Caution, and Note Boxes:
Danger, Warning, Caution, and Note boxes appear throughout
this manual as a means of alerting the installer to important
information.
INDICATES THAT PERSONAL INJURY IS LIKELY OR IMMI-
NENT.
Indicates that serious damage to the heater will occur and
personal injury is possible as well.
Indicates that damage to the heater is possible.
NOTE: Indicates information that requires special attention by
the installer.
— Page 5 —
CAUTION:
! DANGER !
WARNING
The Aqua-Hot 675D is a hydronic (water based) heating sys-
tem, a tank-less hot water system, and a diesel engine preheat-
ing system.
The heating system provides moist, quiet, comfortable, interior
heat with up to five separate, thermostatically-controlled tem-
perature zones, and prevents tank and line freezing in the bays.
The tank-less hot water system produces 120 gallons per hour
of continuous, on-demand, hot water.
The diesel engine preheating system circulates the engine’s
antifreeze solution through an internal heating loop in the
Aqua-Hot and pumps it back through the engine, raising the
engine’s temperature from 30°f to 90°F in about 1 hour.
The same heating loop that preheats the diesel engine allows
the Aqua-Hot system to take surplus heat generated by the mo-
tor home’s diesel engine while running, and use it to heat the
Aqua-Hot system.
This TribridHot™ designated system uses one or a combina-
tion of heat sources to heat FDA-approved Generally Recog-
nized as Safe (GRAS) propylene glycol based antifreeze solu-
tion in the Aqua-Hot’s boiler tank.
The 675D uses the motor home engine’s surplus heat while
driving, one 120 Volt-AC, 2000 Watt electric element and one
240 Volt-AC 4500 Watt electric element heat the system when
shore power is available, and a 12 Volt-DC powered diesel
burner provides heat when dry camping. The heat sources can
be used separately or together.
New Low Emissions Technology virtually eliminates smoke
and smell from the exhaust by reducing total hydrocarbon
emission by 82% making Aqua-Hot the cleanest burning diesel
powered hydronic system available.
Please note that all Danger, Warning, Caution, and Note boxes,
appearing as needed throughout this manual, must be reviewed
and adhered to during the installation procedure in order to
avoid potential hazards, which could result in injury, death,
product damage, or property damage.
Should additional assistance be needed, please contact the
Product Application Department at 1-800-685-4298, Monday
through Friday, between the hours of 7:00 AM and 4:00 PM
Mountain Time.

© 2011 Aqua-Hot®675-D Installation Manual
SECTION 1: AQUA-HOT HYDRONIC HEATING SYSTEM
Diesel Burner, Heat Input (Firing Rate).................................................................................................................................56,000 BTU/hr
Diesel Burner, Fuel Consumption (Continuous Operation)........................................................................................................0.40 gal/hr
Heater, Voltage/Maximum Power Consumption......................................................................................................12 Volt-DC/60 watts
Electric Heating Element specifications...........................................................................................................(2) 120 Volt-AC/2000 watts
Zone Heat Circulation Pump specifications.................................................................................................(3) 12 Volt-DC/21 watts each
Number of Heating Zones...................................................................................................................Maximum of 5, plus Engine Preheat
Domestic Water Heating Capacity ........................................................................................................................Continuous/On-Demand
Dimensions........................................................................................................................................................... 18.5”H x 18.5”W x 36.75”L
Dry Weight......................................................................................................................................................................approximately 186 lbs.
Wet Weight.....................................................................................................................................................................approximately 303 lbs.
NOTE: All vehicle installations must comply with the requirements listed in the Recreational Vehicle Industry Asso-
ciation’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 visit them online at www.rvia.org.
Figure 1
— Page 6 —

© 2011 Aqua-Hot®675-D Installation Manual
SECTION 1: AQUA-HOT HYDRONIC HEATING SYSTEM
Each Aqua-Hot heating system possesses an I.D. label on the
unit itself. This I.D. label details the specifications of the
heater, to what standard it has been tested, and important
safety notices.
Figure 2
— Page 7 —
3 inches
3 inches
1 inch
Use a 25

© 2011 Aqua-Hot®675-D Installation Manual
Figure 3
Domestic Water
Access panel
Heating Zone 1
Outlet Port
Zone 1
Circulation
Pump
Zone 2
Circulation
Pump
Diesel
Burner
Controller
SECTION 1: AQUA-HOT HYDRONIC HEATING SYSTEM
— Page 8 —
Interlock
Switch
Drain Valve
Engine
Preheat
Pump
Diesel
Burner
Zone 3
Circulation
Pump

© 2011 Aqua-Hot®675-D Installation Manual
SECTION 1: AQUA-HOT HYDRONIC HEATING SYSTEM
— Page 9 —
Figure 5
AC Wiring
Zone 1, 2 and 3
Outlet Ports
Product ID Label
Air Release
Valve
Wiring Harness Port
Zone 1, 2 and 3
Inlet Ports
Diesel Fuel
Inlet/Outlet
Ports
Expansion Tank
Connection
Domestic Water
Inlet/Outlet
Ports
Engine Preheat
Inlet/Outlet
Ports
The Aqua-Hot
tank and heating
loop operate at 0.0
psi (zero pressure
system). Air pres-
sure applied to the
tank MUST NOT
exceed 20 psi. Ex-
cess pressure will
result in internal
damage.
WARNING!

© 2011 Aqua-Hot®675-D Installation Manual
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.
NOTE: Secure the mounting tray into place prior to install-
ing the Aqua-Hot.
Remove the access cover fastener from the Aqua-
Hot prior to installation of the Aqua-Hot into the
mounting tray.
Mount the Aqua-Hot securely into the mounting
tray to ensure that the unit does not move or
shift under normal operating conditions
5. Place the Aqua-Hot into the mounting tray. Reference
Figure 9.
NOTE: Remove the bolt securing the front of the access cover
to the mounting tray; this bolt will need to be re-
installed once the total installation procedure is com-
plete. Remove the access cover.
SECTION 2: AQUA-HOT INSTALLATION
Installing the Mounting Tray and 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 outdoors.
1. Reference the following illustrations for mounting infor-
mation:
•
Overall Aqua-Hot dimensions - Figure 7
• Mounting tray information - Figure 8
• I.D. Label noting the “Open Access”
clearance requirement for the front of the heater
- Figure 5
• Service access clearances - Figure 6
NOTE: Be sure to complete the following when installing the
Aqua-Hot:
Inspect the area beneath the mounting location to
insure that no structural members will interfere with
the cut-out for the mounting tray.
Verify that an adequate support system has been
provided for the Aqua-Hot.
2. Cut out the required mounting tray opening. Reference
Figure 8.
3. Install the mounting tray flange into the cut-out opening.
Reference Figure 8.
. Figure 6
— Page 10 —
6

© 2011 Aqua-Hot®675-D Installation Manual
SECTION 2: AQUA-HOT INSTALLATION
— Page 11 —
Figure 7

© 2011 Aqua-Hot®675-D Installation Manual
SECTION 2: AQUA-HOT INSTALLATION
Figure 8
— Page 12 —

© 2011 Aqua-Hot®675-D Installation Manual
SECTION 2: AQUA-HOT INSTALLATION
Figure 9
— Page 13 —

© 2011 Aqua-Hot®675-D Installation Manual
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, preventing the expan-
sion of the heating solution from properly depositing
in the expansion tank.
SECTION 2: AQUA-HOT INSTALLATION
— Page 14 —
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 10.
1. Mount the expansion tank as illustrated in Figure 10.
2. Connect and clamp the overflow tubing from the ex-
pansion tank to the Aqua-Hot’s expansion tank con-
nection. Reference Figure 10.
3. Drill a hole in the bay floor and connect (secure with a
clamp) a long enough piece of overflow tubing so that
it can be connected to the top of the expansion tank
and extend through the bay floor.
Figure 10
Expansion Tank
Connection
CAUTION:
The Aqua-Hot tank and heating loop operate at
0.0 psi (zero pressure system). Air pressure ap-
plied to the tank MUST NOT exceed 20 psi. Ex-
cess pressure will result in internal damage.

© 2011 Aqua-Hot®675-D Installation Manual
SECTION 3: HYDRONIC HEATING SYSTEM
Heat Exchanger Locations and Clearances:
• Place the heat exchangers so that even heat distribu-
tion will be felt throughout the interior of the motor
home. Reference Figure 15A.
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.
•Place the heat exchangers where they will be accessi-
ble for potential servicing and cleaning.
• Centralize and position a heat exchanger in the fresh
water storage tank plumbing bay. Reference Figure
13.
NOTE: In order to achieve the best heating results, place the
heat exchanger as close to the floor of the plumbing
bay as possible (heat will naturally rise).
• Reference Figures 14, 15A, 15B, and 16, for mounting
location information.
•Reference Figure 14 for clearance information.
NOTE: An accessory device is available for the Cozy Heat
Exchanger for the purpose of redirecting the airflow
from the heat exchanger. Reference Figures 17 and
18.
Mounting Requirements:
• Sufficient ventilation (return-air) must be supplied to
each interior heat exchanger. Reference Figure 16.
NOTE: Ventilation (return air) must be supplied from the liv-
ing area. Ventilation (return air) MAY NOT be sup-
plied from the bay area.
NOTE: Mounting the heat exchangers without sufficient ven-
tilation will severely reduce their overall heating per-
formance (heat output).
In order to provide sufficient ventilation, the return-air
registers must be the same size, or larger, than the
outlet-air registers.
Return-air must be supplied from the corresponding
interior heating zones.
Figure 13
Figure 14
— Page 15 —

© 2011 Aqua-Hot®675-D Installation Manual
Figure 15A
Figure 15B
Indicates sample mounting locations for the Cozy heat exchangers. Actual placement and quan-
tity vary based on the individual design of the coach. For specific design assistance, contact Aqua
-Hot at 303-659-8221
— Page 16 —
SECTION 3: HYDRONIC HEATING SYSTEM

© 2011 Aqua-Hot®675-D Installation Manual
SECTION 3: HYDRONIC HEATING SYSTEM
Mounting the Heat Exchangers:
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 20 and 21.
3. Install the hot-air outlet and cold-air return registers.
Reference Figure 16.
NOTE: Please note that a return-air register may not be re-
quired; however, adequate return-air must be pro-
vided to each particular heat exchanger. This means
that the total cross-sectional area of the return-air
opening must be equal to or greater than the cross-
sectional area of the hot-air outlet opening of the
heat exchanger.
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 18. The plenum allows only
the desired outlets to be opened by removing the metal insert
on the vent.
Figure 16
Figure 17
Figure 18
— Page 17 —
Vent installed
In toe-kick area
Cozy Heat
Exchanger
Hose to direct
air to vent
Toe Kick
Board
Plenum

© 2011 Aqua-Hot®675-D Installation Manual
SECTION 3: HYDRONIC HEATING SYSTEM
Figure 21
— Page 18 —
Figure 20

© 2011 Aqua-Hot®675-D Installation Manual
SECTION 3: HYDRONIC HEATING SYSTEM
Figure 22
— Page 19 —
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 elec-
tronic controller. Reference Figure 23.
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
terminal/heating zone location on the electronic con-
troller. Reference Figure 22 and Appendix A.
4. Wire all heat exchangers in a zone in-series. Refer-
ence Figure 23 and Appendix A.
5. Connect all electronic controller wires to the positive
and negative leads of the heat exchanger. Reference
Figures 23 and 24.

© 2011 Aqua-Hot®675-D Installation Manual
SECTION 3: HYDRONIC HEATING SYSTEM
When wiring the heat exchangers in-parallel, the main 18-
gauge wire is split to allow the heat exchanger wires to com-
bine with the main wire to be powered or grounded, respec-
tively.
Figure 22
Figure 24
— Page 20 —
Figure 23