dual water tanks

[stevenrees]

I own a 2008 c/r crossfire toyhauler mk-33. On the passenger side right next to the door, are two water tank access (fill) openings. They are directly above one another. Obviously they are both for water, but which tank does what? I have to fill the bottom tank first to have any water for the water pump to work correctly. If I fill only the top tank, then the pump runs non stop with water only spitting from the faucets.
I have read the manuals I have, and they do not address this issue. So my questions are:

What is the primary function for each tank?

Why won't the top tank allow the water pump to operate?

On another topic, can I run the furnace while driving, so it will be warm when we arrive at our destination?

I am relatively new at this, so please give detailed answers. I have not had the underbelly cover off yet, so I am running blind. ( so to speak )

Thank You in advance for your help>

[salda01]

Nothing is stopping you from running the furnace while driving, other than some states have laws against the propane tanks being open while in motion.

IMHO- it doesn't take that long for the furnace to warm the unit, so why not just turn it on while your setting up camp?

[cwit]

I always travel with the furnace on when it is cold out. As far as the 2 fills I believe one may be for city water or the water will go into your pipes only. The other fill may be your tank fill witch will allow your pump to work. You can't use both at the same time, although you can leave tank full and use when you are boondocking.

[happycampers]

I think cwit is in the right direction. We could probably be more of a help with a pic.
As for your furnace, as mentioned above; local laws will determine if you can or can't. Other than that its probably just a personal preference. I don't run mine while in motion--but I do run my fridge. In fact, I usually only use my furnace once or twice in the spring or fall. Other than that we use the fireplace or our electric heater.

[we-canoe]

On bigger toy haulers there are 2 water tanks just like you thought. I can only guess that the secondary tank,the one that makes the pump sputter must be the secondary and probably(?) fills the main with a small (1/4") line causing the lack of instint water flow into the main.

I know you have said you don't have an area to work on your rig at home but try filling the problematic tank first as soon as you get home to load up. Then load food,bikes...then test the pump again to see if it runs smoother being it was able to set awhile and transfer to the main.

Hope this helps and let us know.

[Hamops]

I have two water hose connection points. One is for filling the drinking water tank, the other is for flushing the black water tank. I kind of think that you are filling your black water tank when you fill the connection that doesn't have a pump.

[Robbie Ribbins]

reguards to your Furn. and Ref. being on while driving. I have read stories about the trailer going Boom when getting fuel due to the flumes. As you know we cannot believe everything we read on the internet. One of my friends has a 5th and his manual advised to turn off this stuff when getting fuel. Just something to think about.

[avvidclif]

While muddling the 2 inlet issue it occurred to me that the large toy haulers probably do have 2 fresh water tanks. Think about it some haul 120 gal of water, that's a BIG tank, with a lot of internal bracing. Makes more sense to have 2 60 gal tanks and a line between them to transfer the water. A primary tank with the pump hookup and a secondary with a transfer line. Just my thoughts.



On the heater, I run my Fridge all the time, but the heater (air and water) is off until I light somewhere. Park, turn on heater and then do your leveling. The air inlet and outlet for the heater makes a great place to warm your hands while doing the outside chores.