While driving and wanting the Cummins to heat the aquahot loops, does the AH switch that is used to preheat the cummins when parked need to be on?
Never thought about it before.
No, it does not
Completed a 135 mile drive today. Pulled into campground. AH diesel burner kicked on immediately after parking (diesel switch was on).
AH loops should have been fully hot from the 135 mile drive.
My experience is that driving heats the AH tank up to about 145-150°. Enough for hot water for most uses after a day of driving. If you want hotter it needs to have the electric or diesel on The diesel can be on while you drive.
Adding a temp sensor and display gives you a lot of information about how the AH works. My temp displays come on when the water pump is on. Red is the AH tank, blue is at the manifold.
The engine preheat switch should be off at all times except for when you want to start a cold engine in frigid conditions.
The engine preheat loop will, as Roger noted, heat the coolant. This will heat the interior to 70+ down to 50, maybe 45 degrees outside. But it does not have the capacity of the 50k btu diesel burner. So, when traveling in freezing conditions, turn on the diesel burner to supplement the preheat loop to keep the interior at 70+ degrees.
When I had my Monaco Dynasty I put a couple of heaters in the back of the coach
would keep the coach HOT inside well below 0 fahrenheit outside. I guess the
Aqua-hots heat exchanger isn't isn't that efficient. In the summer won't the Aqua-
hot water temperature reach engine temperature and if not why.
We are now right at the TX/OK border at Lake Texoma. Had the electric and diesel switches on from our start in Chickasha OK at 44 degree morning. I "think" I had front thermostat set at 70 and back at 63. Warm outside on arrival at 1:30.
I'll pay more attention to thermostats and outside temp on on our next move on 14 Nov.
Arriving in Lake Texoma and parked, suprised the burner kicked on (no gen run on drive). But sounds like all is operating normally.
Learn something new everyday. I thought that it did need to be on in order for the coolant from the engine to reach the aqua hot. So during the day when I'm driving I do have that switch on and have hot water when I get to where I'm going. I will attempt it the next time without the switch on and see if there's a difference. So the engine then pumps the water through the aqua Hot loop without the aqua hot pump circuit on?
The engine water pump does the circulating when driving. Same as the non Aqua Hot coaches with the same loop.