I think a couple of sections in the manual will help explain how this all works:
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©11/2011 Aqua-Hot® 450-DE2 Hydronic Heating System Service Manual—Rev. C
SECTION 1: INTRODUCTION TO THE 450-DE
Engine Preheat System:
The engine preheat system is responsible for heating the motor
home’s engine block in order to make it easier to start-up
when cool weather conditions exist.
When the engine preheat system is activated via the interior
switch panel, the motor home’s engine coolant is circulated
through a dedicated copper coil in the Aqua-Hot’s boiler
tank, where heat from the antifreeze and water heating solution
is transferred to the motor home’s engine coolant. The
heated engine coolant is then transported back to the engine
where it transfers the heat to the engine to gradually warm it.
Additionally, the Aqua-Hot 450-DE includes a motor aide
feature, which uses the circulation of the motor home’s engine
to transport the engine’s coolant from the Aqua-Hot’s
boiler tank to the motor home’s warm engine and back to the
boiler tank. Through this process, the boiler tank is kept
heated, which reduces the time required to bring the tank to
operating temperature for interior heat and continuous domestic
hot water. This motor aide feature is part of the engine
preheating feature and plumbing system, and requires
no action on the user’s behalf to function.
Engine Preheat Switch:
The engine preheat switch activates the engine preheat
pump, which draws the motor home’s engine coolant
through the boiler tank to heat it before returning it to the
engine block to transfer the heat there. Either the diesel burner
switch or the electric element switch must also be
activated in order for the engine preheat feature to function.
The engine preheat switch does not need to be activated for
the motor-aide feature to work and should be shut off when
traveling.
So to conclude, I think what they are saying is that the "motor-aide" is always working.
To increase the temperature in your coach you will need to call for the heat via your thermostat in the comfort control center.
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Jeanne & Rosko 
2017 Cornerstone 45B
2014 Anthem 44B Classic (traded)
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