Controller
©Aqua-Hot®
250-D03 Diesel Series Service Manual
REV 220302
p. 14
Electric (C):
Activating the Electric heating sub-system will energize
the relay which controls the AC electric element.
After tapping this button on the screen, there should
be an audible click from within the Aqua-Hot cabinet. If
there is no such click, verify the functionality of the AC
electric relay.
This test CANNOT directly energize the AC electric
element. It is used only to verify the functionality of the
command and control system.
Burner (D):
This element will energize the Diesel Burner signal
wire, which will then trigger the heat source to activate.
Three-Way Valve (E):
The final element on this screen is not directly related
to the heating subsystems of the Aqua-Hot.
The three-way valve (sometimes known as the summer/
winter valve) controls the flow of the antifreeze and
water heating solution within the Aqua-Hot to deliver
either hot water, or interior heat as requested.
Tapping on this element will change the valve’s
orientation. When this element displays “INT. HEAT” this
valve is oriented to provide interior heat by circulating
heating solution throughout the interior heating zone.
When this element displays “HOT WATER” the valve is
oriented such that heating solution is routed so that
hot water can be provided.
Testing Functionality:
One of the new features of this control system is the ability to
independently activate specific elements within the Aqua-Hot
for testing purposes.
This will allow a technician to activate specific elements within
the Aqua-Hot as needed without jumping wires or utilizing
external power supplies in most troubleshooting cases. Any
elements activated via the testing screen will remain active for
a maximum of five minutes.
Pumps (A):
Both the zone circulation pump
and the boost pump (if applicable)
can be activated by tapping the
corresponding pump on the test
screen.
Fans (B):
All three zone fans can be activated
as needed to test communication
between the zone fans and the
controller. Please note that this will
only work if the zones have been
directly wired to the Aqua-Hot as
described in the installation manual.
Heating sub-systems can be activated independent of their
control circuits and other control sensors as a means of testing
functionality. These systems will activate for a maximum of five
minutes before shutting down.
Activating heating sub-systems in this manner will disregard
all sensor inputs while attempting to activate these heating
systems. As such, if the unit is near operating temperature,
activating these systems may trigger an overheat condition.
Heating sub-system testing is NOT a substitute for
normal operation, and attempting to use it as such may
result in catastrophic damage to the Aqua-Hot�
Figure 10
Figure 11
Figure 12
D
C
E
DO NOT
attempt to activate these sub-systems
while the unit is near operating temperature
B
A
