Vehicle Systems Aqua-Hot AHE-100-04S User manual

Aqua-Hot™ Hydronic Heating System Owner’s Manual 07/04
Aqua-Hot™ Motor Coach Heating System Owner's Manual 08/03
OWNER’S MANUAL
Model Number
AHE-100-04S - 12 VDC.
AHE-130-04X - 12 VDC.

Aqua-Hot™ Hydronic Heating System Owner’s Manual 07/04
Vehicle Systems, Inc.
Warranty Department
15549 East Highway 52
Ft. Lupton, CO 80621
Please Mail To:
OWNER’S INFORMATION
Owner’s Name:
Address:
City: State: Zip Code:
Telephone:
E-mail Address:
Motorhome Model:
Date of Purchase (Motorhome):
Aqua-Hot Model No. (reference Figure 1 “Marking Plate”):
Aqua-Hot Serial No. (reference Figure 1 “Marking Plate”):
Vehicle Systems’ Warranty Department
15549 East Highway 52
Ft. Lupton, CO 80621
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Aqua-Hot™ Hydronic Heating System Owner’s Manual 07/04
���������������TABLE OF CONTENTS
Section 1 Overview Page
1.0 Aqua-Hot Overview 1
1.1 Marking Plate 2
1.2 Aqua-Hot Model Differentiation 3
Section 2 Activating the Aqua-Hot Heating Systems’ Heat Sources
2.1 Diesel-Burner 3
2.2 Electric Heating Element AHE-100-04S Model 4
2.3 Electric Heating Element(s) AHE-130-04X Model 4
Section 3 Operating Instructions
3.1 Zone Thermostat(s) Operation 5
3.2 Using the Domestic Hot Water System 6
3.3 Using the Engine Preheat System 6
3.4 Diesel-Burner Component Overview 7
3.5 Diesel-Burner Operational Flow Chart 7
3.6 Precautions 8
Section 4 Maintenance
4.1 Maintenance Schedule 9
Section 5 Winterization
5.1 Domestic Hot Water System 10
Section 6 Troubleshooting
6.1 General Information 11
6.2 Electronic Controller Diagnostic 11
Referenced Illustrations
Figure 1: Aqua-Hot Hydronic Heating System and Inclusive Components 2
Figure 2: Marking Plate 2
Figure 3: Aqua-Hot Interior Switch Panel 6
Figure 4: Diesel-Burner Components 7
Figure 5: Diesel-Burner Components Requiring Annual Maintenance 9
Figure 6: Electronic Controller 11

Aqua-Hot™ Hydronic Heating System Owner’s Manual 07/04 Page 1
SECTION 1: OVERVIEW
Aqua-Hot
Overview,
continued
NOTE: This Aqua-Hot product utilizes an FDA approved
GRAS Propylene Glycol (P.G.) based water and antifreeze
solution. This P.G. based solution is a Boiler type anti-
freeze, which is Generally Recognized as Safe (”GRAS”) by
the FDA. For additional information regarding this GRAS
antifreeze product, please contact the Technical Support
Department at 1-800-685-4298 or visit the website at
www.vehiclesys.com.
1.0 Aqua-Hot Overview
SECTION 1: OVERVIEW
Aqua-Hot
OverviewThe Aqua-Hot Heating System is an on-board Hydronic Heating
System (heating with hot water) that provides a continuous, on-
demand supply of domestic hot water, as well as interior zone
heating where and when it is needed. Both heating features are
accomplished by a unique 12 Volt-DC Powered Diesel-Fired Burner
and a minimum of one 120 Volt-AC Powered Electric Heating
Element. (As the number of Electric Elements will vary between
Aqua-Hot models, please reference page 5 to determine the
particular model of Aqua-Hot employed.) These two heating sources
maintain the temperature of the Aqua-Hot’s solution of water and
antifreeze. In addition, the Aqua-Hot has been designed to preheat
the vehicle’s engine prior to starting. This preheat feature provides
an easy engine start-up whenever cool weather conditions are
present. Be sure to review Figure 1 for a complete component
overview.
SECTION 1: OVERVIEW

Aqua-Hot™ Hydronic Heating System Owner’s Manual 07/04 Page 2
SECTION 1: OVERVIEW
Aqua-Hot
Overview,
continued
ELECTRONIC CONTROLLER

R
t
o
H
d
l
o
C
Expansion
Tank
Circulation
Pump #3
Engine Preheat
Circulation
Pump
Diesel-Burner
Head
Engine Coolant
Supply
Hot Water
Outlet
(Domestic Water)
Diesel Fuel
Supply
Diesel Fuel
Return
Pressure-Relief
Valve
Cold Water
Inlet
(Domestic Water)
Engine
Coolant
Return
Diesel-Burner
Control
Unit
Mixer
Valve
Electric Heating
Element Access
Panel
Fill / Radiator
Cap
VAC Access
Panel
VAC Service
Input
Thermostat
Access Panel
Marking
Plates
Hour Meter
Heating Zones
Status
#5
#4
#3
#2
#1
Electric Heating
Element Status Low Voltage
Reset
Low Tank-Level
Cutoff
Heating Status
Engine Preheat
Pump
Low Battery
Voltage Fault
Low Temp
Cutoff Status
Overload Fault
Pump #2
Pump #1
Pump #3
Diesel-Burner
Status
Motor Coach Heating Specialists
Electronic
Controller
Switch Panel
Circulation
Pump #2
Circulation
Pump #1
Heating Zones
Supply and Return
Ports
Boiler Tank
Drain Valve
Diesel Electric Engine
Preheat

Figure 1
1.1 Marking Plate
Marking
Plate
AHE-100 02S 12 VDC / 170 Watts
Model Number Diesel-Burner / DC Power
Serial Number Electric Heating
Element / AC Power
Manufactured Date Fuel Type / Firing Rate
02-637 120 VAC, 60 Hz / 1.65 kW
06-02 DIESEL / 50,000 BTU
R
Testing
Engineers
International
Listing No. 02L02
Complies with the requirements
of UL 307A
Made in U.S.A.
For Installation Only in Compartment Completely Closed Off from Living Quarters and Accessible
Only from the Outdoors.
Exhaust system MUST NOT terminate beneath the vehicle or under an openable window or vent.
Combustion Air MUST BE supplied from outside the vehicle.
CAUTION: This appliance operates on both AC and DC Electrical Power.
The AC Powered Electrical Heating Element can be wired using flexible nonmetallic cable (ROMEX).
USE COPPER CONDUCTORS ONLY
Use 25 Amp fuse for over current protection for DC Power Supply.
Use 20 Amp Circuit Breaker for over current protection for AC Power Supply.
Mount Heater near a Bay / Storage Door so Access Cover can be easily removed.
Minimum Heater clearances
Front (Decal Sides) - Open Access
Back - 0 inches
Top - 6 inches
Install in strict compliance with local codes, NFPA
501c and manufacturer’s instructions.
For additional product installation information visit www.aqua-hot.com or call 1-800-685-4298
�
By Vehicle Systems, Inc. Ft. Lupton, CO 80621
Manufactured
Date Box
Serial Number
Box
Model Number
Box
SECTION 1: OVERVIEW
Figure 2
SECTION 1: OVERVIEW

Aqua-Hot™ Hydronic Heating System Owner’s Manual 07/04 Page 3
1.2 Aqua-Hot Model Differentiation
SECTION 1: OVERVIEW
Aqua-Hot
Models Vehicle Systems, Inc. manufactures two individual models of the
Aqua-Hot Hydronic Heating System. The varying factor between the
two models is the number of Electric Heating Elements featured. In
order to determine which of the following Aqua-Hot models has been
employed, locate the Marking Plate on the Heating System (reference
Figures 1 and 2 for Marking Plate information) and view the model
number.
AHE-100-04S:
This model features a single 120 VAC/1650 Watt Electric Heating
Element. Reference page 7 for operating instructions.
AHE-130-04X:
This model features two 120 VAC/2000 Watt Electric Heating
Elements. Reference page 8 for operating instructions.
SECTION 2: ACTIVATING THE AQUA-HOT’S HEAT SOURCES
Diesel-
Burner
Operation 2.1 Activating the Diesel-Burner
Diesel-Burner
Turn the Diesel switch ON; reference Figure 3. This procedure will
activate the Diesel-Burner and the indicator light located on the Diesel
switch. Allow 10-20 minutes for the Aqua-Hot System to reach operating
temperature. Please note that the Diesel-Burner is the primary heat
source for heating both the interior and the domestic hot water (such as
when cool ambient temperatures exist and/or when there is a high de-
mand for domestic hot water).
Please read the complete Owner’s Manual prior to operating your Aqua-
Hot Heating System. Also, be sure to fill out and mail in your Owner’s
Information Card located at the front of this manual.
NOTE: The “Diesel” switch can also be used to reset a 12 Volt-DC Low
Voltage Fault. Please reference Section 6.
SECTION 1: OVERVIEW

Aqua-Hot™ Hydronic Heating System Owner’s Manual 07/04 Page 4
2.2 Activating the Electric Heating Element for the AHE-100-04S Model
SECTION 2: ACTIVATING THE AQUA-HOT’S HEAT SOURCES
Electric
Element
Operation
AHE-100-04S
Electric Heating Element
Turn the Electric switch ON; reference Figure 3. This procedure will
activate the 120 VAC Electric Heating Element and the indicator light
located on the Electric switch. Allow 1-2 hours for the Aqua-Hot System to
reach operating temperature. Please note that the Electric Heating
Element is a secondary heat source for heating both the interior and the
domestic hot water during low heating demand situations (such as when
moderate ambient temperatures exist and/or when there is a low demand
for domestic hot water).
NOTE: Both the Diesel-Burner and the Electric Heating Element are
thermostatically controlled. Either, or both, heating sources will
automatically maintain the temperature of the Aqua-Hot's water and
antifreeze solution between approximately 160-190 (+/- 5) degrees
Fahrenheit. To heat your motorhome / domestic hot water, simply
choose the desired heat source(s) and leave the switch(s) (i.e., Diesel
and/or Electric) ON.
2.3 Activating the Electric Heating Element(s) for the AHE-130-04X Model
SECTION 2: ACTIVATING THE AQUA-HOT’S HEAT SOURCES
Electric
Element
Operation
AHE-130-04X
Electric Heating Element(s)
Low:
Turn the Electric switch ON in conjunction with the High / Low switch
placed in the LOW position; reference Figure 3. This procedure will
activate one of the two 120 VAC Electric Heating Elements and the
indicator lights located on both the Electric and High / Low switches. Allow
1-2 hours for the Aqua-Hot System to reach operating temperature.
High:
Turn the Electric switch ON in conjunction with the High / Low switch
placed in the HIGH position; reference Figure 3. This procedure will
activate both of the 120 VAC Electric Heating Elements and the indicator
lights located on both the Electric and High / Low switches. Allow 0.5-1
hour for the Aqua-Hot System to reach operating temperature.
NOTE: In order to operate both Electric Heating Elements, you will either
need a 50-AMP Shore Power electrical source, or your Generator must be
capable of producing the necessary VAC electrical power requirements.
Please contact the manufacturer of your specific motorhome for information
regarding the specifics of your motorhome’s electrical system.
SECTION 2: ACTIVATING THE AQUA-HOT’S HEAT SOURCES

Aqua-Hot™ Hydronic Heating System Owner’s Manual 07/04 Page 5
SECTION 3: OPERATING INSTRUCTIONS
Comfort
Control
3.1 Zone Thermostat(s) Operation
Interior Room Thermostats
Simply adjust each Interior Room Thermostat to the desired temperature.
Then, whenever an Interior Room Thermostat “calls-for-heat,” the Aqua-
Hot’s Circulation Pump(s) and Interior Heat Exchanger Fans will be
activated. These devices together will supply warmth and comfort to each
interior heating zone. Please contact your specific motorhome
manufacturer for the exact location of the Interior Room Thermostat(s).
Fresh Water Tank Thermostat
Simply adjust the Thermostat (i.e., Bay Heating) to approximately 40
degrees Fahrenheit. This will prevent freezing of the domestic water
storage system.
Please contact your specific motorhome manufacturer
for the exact location of the Fresh Water Tank Thermostat.
SECTION 3: OPERATING INSTRUCTIONS
3.2 Using the Domestic Hot Water System
When the Aqua-Hot is at operating temperature, the domestic water is
automatically heated as it is being used. Because the Aqua-Hot does not
store any hot water, simply open any hot water faucet and a continuous
supply of domestic hot water will be present within a few seconds. This
hot water feature is continuous and is accomplished by the Aqua-Hot’s
Domestic Hot Water Heating System. Please note that the Diesel
switch must be ON to get an unlimited supply of hot water (i.e., during
showers).
3.3 Using the Engine Preheat System
When the Aqua-Hot is at operating temperature and the Diesel-Burner
and/or the Electric Heating Element(s) switch(s) is ON, follow these
simple instructions:
A. Turn the Aqua-Hot's Engine Preheat switch ON; reference Figure 3.
This procedure will activate the Engine Preheat Circulation Pump and
circulate the engine's coolant through the Engine Preheat System.
This feature will adequately warm the engine for easy start-ups on
cool mornings.
NOTE: Allow approximately 1 to 2 hours of engine preheating run
time. Preheat duration will be shortest when the Diesel switch is ON.
Hot Water
Engine
Preheat
SECTION 3: OPERATING INSTRUCTIONS

Aqua-Hot™ Hydronic Heating System Owner’s Manual 07/04 Page 6
SECTION 3: OPERATING INSTRUCTIONS
Diesel-
Burner
Component
Overview
1. Control Unit 6. Fuel Solenoid 11. Combustion Chamber
2. Motor 7. Electrode Holder 12. Exhaust Port
3. Ignition Coil 8. Ignition Electrodes 13. Flame Sensor
4. Clutch 9. Fuel Nozzle 14. Fuel Pump
5. Combustion Air Blower 10. Heat Exchanger 15. Fuel Ports (Supply / Return)
16.Combustion Air Intake Port,
with Adjustable Shutter
Figure 4
3.4 Diesel-Burner Component Overview
SECTION 3: OPERATING INSTRUCTIONS
B. Turn OFF the Aqua-Hot's Engine Preheat switch whenever engine
preheating is not desired.
NOTE: The Aqua-Hot's Engine Preheating System acts as a supple-
mental heating source in addition to the Diesel-Burner and the Electric
Heating Element(s). While traveling, the engine's heated coolant will
automatically pass through the Engine Preheat / Motoraide System,
transferring heat into the Aqua-Hot's Boiler Tank. This design feature
reduces the total operating hours of the Diesel-Burner and the Electric
Heating Element(s).
Engine
Preheat,
continued
Figure 3
Diesel Electric Engine
Preheat

Indicator
Light
Diesel ElectricEngine
Preheat

Low
High
Indicator
Light
AHE-100-04S Model AHE-130-04X Model
SECTION 3: OPERATING INSTRUCTIONS

Aqua-Hot™ Hydronic Heating System Owner’s Manual 07/04 Page 7
SECTION 3: OPERATING INSTRUCTIONS
Diesel-
Burner
Operational
Flow-Chart
NOTE:
If the Aqua-Hot’s coolant
temperature is
approximately 190 (+/- 5)
degrees Fahrenheit, or
higher, the Motor (#2)
will not operate. Only
when the coolant
temperature has
dropped below 160
(+/- 5) degrees
Fahrenheit, and the VDC
/ VAC Control
Thermostat is calling for
heat, will the Motor (#2)
begin to operate
.
Operation sequence once
the Aqua-Hot’s Diesel
switch is turned ON
.
NOTE:
The Diesel switch’s
Indicator Light will
illuminate (reference
Figure 3), while the
Heating Status and
Diesel-Burner Status
lights illuminate on the
Electronic Controller,
reference Figure 6
.
The Motor (#2), which
turns the Combustion
Air Blower (#5) and
drives the Fuel Pump
(#14), will begin to
operate.
After approximately 10 - 25
seconds, the Fuel
Solenoid (#6) opens and
fuel is sprayed into the
Combustion Chamber
(#11) through the Fuel
Nozzle (#9).
Once the ignited air-fuel
mixture (FLAME) is
observed by the Flame
Sensor (#13), the Ignition
Coil (#3) will automatically
switch OFF. The
combustion process now
continues to operate
unassisted.
Simultaneously the
Ignition Coil (#3)
produces a high voltage
spark across the Ignition
Electrodes (#8), which
ignites the incoming
air-fuel mixture
.
3.5 Diesel-Burner Operational Flow-Chart
Reference Figure 3 for all numbers indicated inside parentheses. (e.g., #8).
SECTION 3: OPERATING INSTRUCTIONS
The combustion process will
continue to operate in this
manner until one of the following
occurs:
A.) The VDC / VAC Control
Thermostat, which senses
coolant temperature, reaches the
preset temperature of
approximately 190 (+/- 5)
degrees Fahrenheit
.
NOTE:
If process "A" occurs, the
Heating Status and Diesel-
Burner Status lights on the
Electronic Controller will go
OFF, reference Figure 6.
B.) The Aqua-Hot’s Diesel switch
is turned OFF.
NOTE:
If process "B" occurs, the Diesel
switch’s Indicator Light, on the
Switch Panel (reference Figure
3), will go OFF along with the
Heating Status and Diesel-
Burner Status lights on the
Electronic Controller, reference
Figure 6.
SUMMARY:
The Aqua-Hot’s Diesel-
Burner is in stand-by
mode anytime the operator
moves the Diesel switch
(reference Figure 3) to the
ON position. The Diesel-
Burner will then
automatically ignite and
maintain the coolant
temperature in the Aqua-
Hot’s Boiler Tank without
additional involvement
from the operator.
1.) The Motor (#2) will
shut-off once the three (3)
minute purge-cycle has
expired.
-THEN-
2.) The Aqua-Hot’s Diesel-
Burner will automatically
turn back ON once the
coolant temperature
reaches the preset
temperature of
approximately 160 (+/- 5)
degrees Fahrenheit.
The Motor (#2) will
continue to run for
approximately three (3)
additional minutes. This
process is referred to as
the purge-cycle, which
cools down the heater’s
internal components
and purges the
Combustion Chamber
(#11) of any residual
exhaust gases.
Once the heater switches
OFF, thermostatically or
manually, the Fuel
Solenoid (#6) closes,
which interrupts the supply
of diesel fuel to the Fuel
Nozzle (#9).
NOTE:
When the Aqua-Hot’s
Diesel-Burner is switched
OFF, by the VDC / VAC
Control Thermostat, the
following process will take
place:
3.5 Diesel-Burner Operational Flow-Chart, continued
Diesel-
Burner
Operational
Flow-Chart,
continued
SECTION 3: OPERATING INSTRUCTIONS

Aqua-Hot™ Hydronic Heating System Owner’s Manual 07/04 Page 8
SECTION 3: OPERATING INSTRUCTIONS
Important
Information
3.6 Precautions
WARNINGS:
• The Aqua-Hot's Exhaust is HOT!
• DO NOT park in areas where dry conditions exist underneath the
vehicle, as a fire may result (e.g., in a dry grassy field).
• DO NOT operate the Aqua-Hot’s Diesel-Fired Burner inside an
enclosed building.
•The Heater should be switched OFF when refueling.
CAUTION: DO NOT operate the Diesel-Burner and/or the Electric
Heating Element(s) without the water and antifreeze solution in the Aqua-
Hot’s Boiler Tank. Failure to do so will cause serious damage to the
Heater.
SECTION 4: MAINTENANCE
Upkeep 4.1 Maintenance Schedule
Monthly
Check the Aqua-Hot's solution of water and antifreeze to ensure that it is
at the proper level. Do this by visually checking the coolant level in the
Aqua-Hot's Expansion Tank; reference Figure 1. Please note that the
coolant level should be checked only when the Aqua-Hot is at maximum
operating temperature (i.e., when the Diesel-Burner cycles OFF),
“HOT.”
WARNING: When the Aqua-Hot is at maximum operating temperature
(HOT), DO NOT loosen the Radiator Cap. If removed, scalding by hot
vapor or coolant could result.
NOTE: This Aqua-Hot product utilizes a Propylene Glycol (P.G.) based
water and antifreeze solution. This P.G. based solution is a Boiler type
antifreeze, which is Generally Recognized as Safe (“GRAS”) by the FDA.
For additional information regarding this GRAS antifreeze product, please
contact us at 1-800-685-4298 or visit our website at
www.vehiclesys.com.
If the coolant needs replenishing, fill the Aqua-Hot’s Expansion Tank to the
FULL HOT level mark. Be sure to use a 50/50 mixture of water and (P.G.)
antifreeze.
SECTION 4: MAINTENANCE

Aqua-Hot™ Hydronic Heating System Owner’s Manual 07/04 Page 9
SECTION 4: MAINTENANCE
Annually
WARNING: Before cleaning or servicing, disconnect all power supplies.
To keep your Aqua-Hot running smoothly, it is ideal to have the Diesel-Burner
tuned-up annually. A tune-up should consist of a new Fuel Nozzle and Fuel
Filter, along with a thorough cleaning of the Combustion Chamber, if
necessary (reference Figure 5). To ensure maximum Diesel-Burner
performance, always use the recommended Fuel Nozzle (i.e., 0.35 GPH) and
Fuel Filter (i.e., 10 Micron) when replacing these parts. Reference the Aqua-
Hot “Parts Manual” for spare parts information. If detailed replacement
instructions are needed, please reference the Aqua-Hot “Shop Manual” or
contact the Technical Support Department at 1-800-685-4298 for the nearest
Aqua-Hot Service Center.
CAUTION:DO NOT operate the Diesel-Burner and/or the Electric Heating
Element(s) without the water and antifreeze solution in the Aqua-Hot’s Boiler
Tank. Failure to do so will cause serious damage to the Heater.
Upkeep,
continued
Fuel Nozzle
(0.35 GPH)
Combustion
Chamber
Fuel Filter
(10 Micron)
Figure 5
SECTION 5: WINTERIZATION
5.1 Domestic Hot Water System
The Aqua-Hot's Domestic Hot Water Heating System must be completely
drained of domestic water any time the heater is stored where freezing
temperatures may be experienced.
CAUTION: Not winterizing your Aqua-Hot when freezing temperatures
are present will result in serious damage to the Aqua-Hot's Domestic
Hot Water Heating System.
NOTE: The Aqua-Hot can still be used for interior zone heating even if the
domestic hot water system has been drained and winterized.
Please follow the instructions listed below when winterizing the Aqua-Hot’s
Domestic Hot Water Heating System:
A. Completely drain the fresh water storage tank.
NOTE: If your motorhome is equipped with appliances that use fresh
water (e.g., ice makers, water purifiers, etc.) follow the manufacturer's
recommendation for winterization.
B. Disconnect the domestic water demand pump's suction line from the
fresh water storage tank.
Storage
SECTION 5: WINTERIZATION

Aqua-Hot™ Hydronic Heating System Owner’s Manual 07/04 Page 10
SECTION 5: WINTERIZATION
C. Attach an adequate piece of hose onto the suction side of the domestic
water demand pump.
D. Place the opposite end of the hose into an adequate supply of FDA
approved RV-Antifreeze.
E. Open / close all interior and exterior water faucets, one at a time, until
only pure RV-Antifreeze is present. Perform this procedure for both the
hot and cold faucets.
F. Remove the hose and reconnect the domestic water demand pump's
suction line to the fresh water storage tank.
G. Disconnect all electrical power supplies to the Aqua-Hot during storage.
NOTE: For de-winterization, completely fill the fresh water storage tank.
Open / close all interior and exterior water faucets, one at a time, until only
clear water is present / visible.
CAUTION: If you are disinfecting your potable water system after de-
winterizing, be sure to follow RVIA’s “Instruction for Disinfection of
Potable Water Systems on Recreation Vehicles.” These instructions
can be found in the ANSI A119.2 Handbook for Recreational Vehicle Stan-
dards. To receive a copy of this RVIA Standard, write to: Recreation
Vehicle Industry Association, 1896 Preston White Drive, P.O. Box
2999, Reston, VA 20195-0999 or visit the RVIA website at www.rvia.com.
Storage,
continued
SECTION 6: TROUBLESHOOTING
6.1 General Information
If the Aqua-Hot’s Diesel switch “Indicator Light” does not illuminate, and the
Diesel-Burner is not functioning, locate the Electronic Controller (Figure 6)
and check the following:
A. Check the Aqua-Hot’s Electronic Controller for any RED lights indicating a
fault condition. Reference Figure 6 and the Electronic Controller Trouble-
shooting section to identify these fault conditions.
B. Check for loose wire connections on the Electronic Controller’s Terminal
Strips/Plugs. When checking for loose Terminal Strips/Plugs, remove the
Electronic Controller Faceplate by unscrewing the four cover screws.
C. Remove the Aqua-Hot’s Access Cover and check for loose plug connec-
tors on the Diesel-Burner's Control Unit (located on the under side);
reference Figure 1..
D. Check to ensure that the vehicle’s fuel tank has a sufficient level of fuel.
E. If your Aqua-Hot still fails to operate, please contact the Technical Sup-
port Department at 1-800-685-4298 for additional troubleshooting assis-
tance or visit our website at www.vehiclesys.com.
General
Information
SECTION 6: TROUBLESHOOTING

Aqua-Hot™ Hydronic Heating System Owner’s Manual 07/04 Page 11
SECTION 6: TROUBLESHOOTING
6.2 Electronic Controller Diagnostic
#5
#4
#3
#2
#1
Electric Heating
Element Status Low Voltage
Reset
Low Tank-Level
Cutoff
Heating Status
Engine PreHeat
Pump
Low Battery
Voltage Fault
Low Temp
Cutoff Status
Overload Fault
Pump #2
Pump #1
Pump #3
Diesel-Burner
Status
Heating Zones
Status
ELECTRONIC CONTROLLER

R
Electronic
Controller
Figure 6
SECTION 6: TROUBLESHOOTING
Electronic
Controller,
continued
Low Tank-Level Cutoff Indicator Light:
This indicator light will illuminate RED when either the Electric Heating
Element(s) and/or Diesel-Burner have automatically shut down due to a low
water and antifreeze solution level inside the Aqua-Hot’s Boiler Tank. This fault
will automatically reset when the low level condition is corrected.
Low Battery Voltage Fault Indicator Light:
This indicator light will illuminate RED whenever the VDC voltage level is too
low for the Aqua-Hot to operate properly. This fault must be manually reset
after the voltage level has been restored to the VDC battery system, reference
Low Voltage Reset below.
Low Voltage Reset (Button):
Overload Fault Indicator Light:
This indicator light will illuminate RED whenever one of the following conditions
have occurred:
1. The Aqua-Hot is off due to an electrical overload (i.e., short) in the main
VDC power supply circuitry.
The Aqua-Hot’s Electronic Controller must be manually reset whenever the
Low Battery Voltage Fault indicator light has been activated. The Electronic
Controller can be reset either by depressing the “Low Voltage Reset” button
located on the Electronic Controller (use a thin, straight, nonmetallic object to
access the reset button through the small hole in the faceplate) or by turning
OFF the Diesel switch on the Heater’s Interior Switch Panel for approximately
30 seconds, then turning the switch back ON.
SECTION 6: TROUBLESHOOTING

Aqua-Hot™ Hydronic Heating System Owner’s Manual 07/04 Page 12
SECTION 6: TROUBLESHOOTING
The Aqua-Hot will automatically restart once the electrical overload (i.e., short)
and/or high heat condition is corrected.
Heating Zones Status Indicator Lights:
These five indicator lights (separately) will illuminate GREEN whenever a
Zone Thermostat, for each particular zone, is calling for heat. The GREEN
indicator lights also indicate that VDC power is being supplied to the particular
interior heating zone’s Heat Exchangers (i.e., fan motors). If any of the five
indicator lights illuminate RED, it indicates that an electrical overload condition
(i.e., short) has occurred in a particular heating zone’s circuitry.
NOTE: A short in either a heating zone’s Interior Room Thermostat or
heating zone’s Heat Exchanger circuit will cause the indicator light to
illuminate RED.
Pumps #1, #2, and #3 Indicator Lights:
These indicator lights (separately) will illuminate GREEN whenever a
Circulation Pump is operating. If any of the three indicator lights illuminate
RED, it indicates that an electrical overload condition (i.e., short) has occurred
in the particular component’s circuitry.
NOTE: The Zone Circulation Pumps (separately) are activated whenever
a Zone Thermostat calls for heat.
Electronic
Controller,
continued
2. The Aqua-Hot is off due to a combination of high electrical VDC power
loads and a high surface temperature of the Electronic Controller.
SECTION 6: TROUBLESHOOTING
is operating. Please note that this light will only be active if the Engine Preheat
switch is ON in conjunction with either the Diesel and/or the Electric switch. If
this indicator light illuminates RED, it indicates an electrical overload condition
(i.e., short) has occurred in this particular component’s circuitry.
Heating Status Indicator Light:
This indicator light will illuminate GREEN whenever the Aqua-Hot’s VDC / VAC
Control Thermostat is calling for heat, allowing the water and antifreeze
solution in the Aqua-Hot’s Boiler Tank to be heated by either the Diesel-Burner
and/or the Electric Heating Element(s). When this indicator light is off, no
heat is being supplied to the Aqua-Hot’s Boiler Tank.
NOTE: The Aqua-Hot’s VDC / VAC Control Thermostat will automatically
activate the Diesel-Burner and/or the Electric Heating Element(s), only if
the Diesel and/or Electric switch is in the ON position. In order to heat your
motorhome / domestic hot water, simply choose the desired heat
source(s) and leave the switch(s) (i.e., Diesel and/or Electric) ON.
Electric Heating Element Status Indicator Light:
This indicator light will illuminate GREEN whenever the Aqua-Hot’s Electric
Heating Element(s) is operating and providing heat to the Aqua-Hot’s Boiler
Tank. Please note that this light will only be active if the Electric switch is in
the ON position. If this indicator light illuminates RED, it indicates an electrical
overload condition (i.e., short) has occurred in the Electric Heating Element’s
VDC powered circuitry.
Electronic
Controller,
continued
Engine Preheat Pump Indicator Light:
This indicator light will illuminate GREEN whenever the Engine Preheat Pump
SECTION 6: TROUBLESHOOTING

Aqua-Hot™ Hydronic Heating System Owner’s Manual 07/04
WARRANTY INFORMATION
Vehicle Systems, Inc. warrants the AQUA-HOT Heater to be free from defects in material and work-
manship under normal use and service for a period of two (2) years on both parts and labor com-
mencing upon the original date of registration of the vehicle. The warranty period may not however,
exceed 36 months from the orignal date of delivery by Vehicle Systems, Inc. Replacement parts are
warranted for the remainder of the Heater's standard warranty period or for six months (180 days),
whichever is greater.
This warranty is conditional upon proper use of the Heater by the end-user. This warranty
does not apply to damage or failure of the AQUA-HOT Heater, or the vehicle into which it
was installed, due to improper installation, assembly, maintenance, abuse, neglect, acci-
dent, or the use of parts not supplied by Vehicle Systems, Inc. Vehicle Systems is not re-
sponsible for incidental or consequential damages.
The intent of this warranty is to protect the end-user of the heating system from such defects, which
would occur in the manufacture of the product. The warranty is not intended to protect the end-user
from problems, which are outside the ability of Vehicle Systems’ control.
To obtain warranty repair authorization or for additional product information, please contact the
Technical Support Department at 1-800-685-4298 (8 AM to 5 PM Mountain Standard Time).
- FOR AQUA-HOT MODELS -

Aqua-Hot™ Hydronic Heating System Owner’s Manual 07/04
Date Service Performed Service Center
OWNER’S SERVICE LOG:
Date Service Performed Service Center
OWNER’S SERVICE LOG:
(Continued)

Aqua-Hot™ Hydronic Heating System Owner’s Manual 07/04
-MEMO-
-MEMO-

Aqua-Hot™ Hydronic Heating System Owner’s Manual 07/04
Aqua-Hot™ Motor Coach Heating System Owner's Manual 08/03
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15549 East Highway 52 · Fort Lupton, Colorado 80621 · 1-800-685-4298 · Fax: [phone]
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