Service manual

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© January 2013 Aqua-Hot
®
600-D01 Series Hydronic Heating System Service Manual - Rev. A
SECTION 1: INTRODUCTION TO THE AQUA-HOT 600 SERIES
This service and parts manual is designed to aid
trained and qualified service technicians with
the process of troubleshooting and servicing the
Aqua-Hot 600 series Hydronic heating system.
The Aqua-Hot 600 heating system features a 12 Volt-DC
powered diesel-burner and two AC powered electric heating
element. These two heating sources are used in conjunction
with an FDA-approved “GRAS” (Generally Recognized as
Safe) propylene glycol based boiler antifreeze and water
heating solution in order to provide a continuous supply of
domestic hot water, interior/fresh water tank heating, inde-
pendent interior zone heating, and engine preheating. Be
sure to reference Figures 3 through 5 for a complete
component overview.
Please note that all Danger, Warning, Caution, and Note box-
es, appearing as needed throughout this manual, must be
reviewed and adhered to during any service procedure in
order to avoid potential hazards, which could result in injury,
product damage, or property damage.
Should additional assistance be needed, please contact the
technical support department at 1-800-685-4298, Monday
through Friday, between the hours of 7:00 AM and 4:00 PM
Mountain Standard Time.
Danger, Warning, Caution, and Note Boxes:
Danger, Warning, Caution, and Note boxes appear through-
out this manual as a means of alerting the service technician
to important information.
INDICATES THAT PERSONAL INJURY IS LIKELY OR
IMMINENT.
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 atten-
tion by the service technician
Understanding the Aqua-Hot 600’s Major Systems:
The basis for the Aqua-Hot heating system’s functionality is
the antifreeze and water heating solution, which is comprised
of water that is distilled, de-ionized, or soft, as well as FDA-
approved “GRAS” propylene glycol based boiler antifreeze.
Through this solution’s ability to maintain and transfer heat,
the Aqua-Hot’s three major systems: the domestic water
system, engine preheat system, and interior heating system,
are able to function effectively. This antifreeze and water
heating solution is contained within the Aqua-Hot’s boiler
tank and is heated by the diesel-burner when its operating
criteria are met and/or the electric heating element when its
operating criteria are met. In order for the diesel-burner to
be considered as a heating source by the Aqua-Hot, it must
have an adequate fuel supply, receive power from the elec-
tronic controller, and be selected as a heating source from the
interior switch panel. In order for the electric heating ele-
ment to be considered as a heating source by the Aqua-Hot,
it must receive power from either a generator or from shore
power and be selected as a heating source from the interior
switch panel. Once the antifreeze and water heating solution
achieves operating temperature (as determined by the Aqua-
Hot’s control thermostat), the domestic water system, the
engine preheat system, and the interior heating system are
permitted to operate as needed.
Domestic Hot Water System:
When hot water is requested, domestic water from the motor
home’s fresh water tank is transported through a copper coil
in the Aqua-Hot’s boiler tank where heat is transferred from
the heated antifreeze and water heating solution to the do-
mestic water flowing through the copper coil. The heated
domestic water then flows through the tempering valve to be
mixed with cool water from the fresh water tank to achieve
an appropriate temperature before it flows to the faucet re-
questing hot water.
Engine Preheat System:
The engine preheat system is responsible for heating the mo-
tor home’s engine block in order to make it easier to start-up
when cool weather conditions exist.