How does trailer know which water source to use - Fresh or City?

[JoeInPA]

If I have filled my fresh water tank to prepare for boondocking next day, but am connected to city (water pump off), will my trailer use the city or fresh supply?

[sdelam]

It can not use the fresh water tank unless you turn the pump on.

[moose074]

X2

[JoeInPA]

Sorry for the dumb question. First time using the city water hook up. Had trailer less than 2 weeks, and this is first time had to think about it. Need every drop of the fresh tank water for a multi-day boondocking, just wanted to be positive. Thank you for the fast replies.

[Cabinfever97]

It will use the city source. I have had the pump on while connected to city water and it did not run. My thought is the city water pressure kept the pump from coming on.

[sdelam]

Getting a few extra gallons of fresh water is relatively easy. If there isn't a source near the camping spot you can bring a few 5 gallon cans, or a fancy water bladder.

Normally its the emptying of the grey/black tanks that is a bit more difficult. Use your water wisely, short navy showers, dont fill the sink to wash dishes, etc.. Enjoy!

[nomad297]

Your RV has a 38 gallon fresh water tank, a 30 gallon black water tank and a 30 gallon gray water tank.

Since this will be your first time roughing it, you should consider bringing some extra fresh water if you will be a long ways away from a supply to refill. Also, keep in mind that your gray tank will fill up pretty quickly, just as your fresh water tank will empty pretty quickly if you don’t consciously conserve water. You may want to research the area to make sure you have a place to get fresh water and dump your tanks in case you exceed your limits. It would be a shame to have to cut your trip short just because you ran out of water or filled your black or gray tank before you were expecting to.

Have you considered these things already? If so, what is your plan?

Bruce

[nomad297]

Originally Posted by sdelam

Normally its the emptying of the grey/black tanks that is a bit more difficult. Use your water wisely, short navy showers, dont fill the sink to wash dishes, etc.. Enjoy!

I agree.

Paper plates and bowls are a wonderful thing when it comes to conserving water.

Bruce

[mac1_131]

Originally Posted by JoeInPA

If I have filled my fresh water tank to prepare for boondocking next day, but am connected to city (water pump off), will my trailer use the city or fresh supply?

To actually answer your question, there should be some one way valves in there.

So when city water is connected and under pressure, that is what you will use and one way valves should protect any backflow in to your fresh water tank.

When city water is disconnected and the pump is on, one way valves will prevent it pumping all your water out the city water inlet.

[JoeInPA]

Originally Posted by sdelam

Getting a few extra gallons of fresh water is relatively easy. If there isn't a source near the camping spot you can bring a few 5 gallon cans, or a fancy water bladder.

Normally its the emptying of the grey/black tanks that is a bit more difficult. Use your water wisely, short navy showers, dont fill the sink to wash dishes, etc.. Enjoy!

Roger that. Brought 7 gallon water jugs plus smaller drinking water bottles. We boondocked last weekend near home as a trial run, and I went full nerd and measured the remaining fresh water once done, and calculated the amount used by total # of showers, toilet days per person, etc. I think I have a baseline for usage, but will do the same this trip to see if my initial calcs hold up.

No, I will NOT go as far as measuring black and grey tanks other than the onboard LED panel. But I did want more exact measurements on the fresh than ballpark LED levels. Besides, the waste tanks can’t hold any more than the fresh tank capacity, so as long as do military showers and bare minimal use for the one overnight on city water, I think the waste tanks will be ok.

Thanks again very much, all. #NoobCamper

[JoeInPA]

Originally Posted by nomad297

I agree.

Paper plates and bowls are a wonderful thing when it comes to conserving water.

Bruce

Agree 100%. Now, if you can only convince my hippie, tree-hugger DW that wasting some tree paper is not going to cause the earth to implode... Don’t bother, I've been trying until I gave up. I tell her fresh water is a far worse thing to waste than paper, but it never computes with her. We are washing dishes with jug water and emptying it outside.

[nomad297]

Originally Posted by JoeInPA

the waste tanks can’t hold any more than the fresh tank capacity, so as long as do military showers and bare minimal use for the one overnight on city water, I think the waste tanks will be ok.

The portion I bolded is certainly true, but you are planning on bringing extra fresh water, so you could, possibly, fill your tanks to their capacity.

Bruce

[nomad297]

Originally Posted by JoeInPA

Agree 100%. Now, if you can only convince my hippie, tree-hugger DW that wasting some tree paper is not going to cause the earth to implode... Don’t bother, I've been trying until I gave up. I tell her fresh water is a far worse thing to waste than paper, but it never computes with her. We are washing dishes with jug water and emptying it outside.

While we do still use paper plates, my wife likes to buy bamboo plates and bowls in bulk quantities. They do cost more than paper products, but using bamboo instead of trees should be a good compromise for your wife.

EDIT: I forgot to mention that my wife also finds plates and bowls made form palm leaves.

Bruce

[Flybob]

The trailer does not know or care. There is one common system that is fed by pubic water and water from water pump. It is suggested that when you are connected to public water you turn the water pump off to reduce the possibility of miss-seating the backflow valve allowing water to enter the FW tank. See below.

[uhduh camping]

To maybe help you out further. If you do wash some dishes save water in a tub of some sort we found one that fits perfectly in sink. Use that water to fill toilet. Every drop counts!

[bikendan]

Originally Posted by JoeInPA

If I have filled my fresh water tank to prepare for boondocking next day, but am connected to city (water pump off), will my trailer use the city or fresh supply?

Moved from General Motorhome Discussion section to the Plumbing and Water Systems sub-forum.

[Garrette]

A lot of folks use this method to extend the capacity of their grey water tank. Remove your safety dump line cap and Place a twist on valve (Valterra) at the end of the dump pipe and close it. You could use the cap but a value is better for obvious reasons. Open both the grey and black bal es and the tanks will equalize thus giving your a little more grey water capacity. When y ou dump, connect your hose to the third valve and dump and flush normally.
Remove the third valve, clean and stow, capping the end of the line for travel.

[jimmoore13]

Many alluded to carrying extra water. My recommendation...assuming your TV can carry them, or that you have excess CCC capacity in your rig...4 of these.

https://smile.amazon.com/Reliance-Pr...s%2C277&sr=8-2

Note that the caps are ideally suited to create a home-built adapter for pouring into the gravity fill. The jug cap has a standard 1/2" NPT (pipe thread) fitting in the center that will accept adaptation to a fill hose.
Adapter:
~ One replacement cap for Reliance jug: https://smile.amazon.com/Reliance-Pr...%2C273&sr=8-22
~ 1/2" NPT (pipe thread) to "barb" plastic adapter: https://smile.amazon.com/Parker-Hann...7585859&sr=8-9 Virtually all hardware stores have these...most are black or grey.
~ about 15" of 1/2" clear plastic tubing: https://smile.amazon.com/Duda-Energy...7585962&sr=8-3 Sold by the foot at said hardware store.
~ 1/2" hose clamp: https://smile.amazon.com/Koehler-Ent...7586041&sr=8-4 Guess where you can get these.

I also drill out the air vent hole to 3/8", because the adapter can dump water faster than the vent hole (about 1/4") can admit air. The 3/8" is small enough to not compromise the seal on the air vent cap, but large enough to admit air as fast as water goes out...no glug-glug-glug.

Using this adapter, I can dump a 7 gallon jug of water into my gravity fill in about 2 to 3 minutes.

Note that water weighs 8.3 pounds per gallon. 7 gallons plus jug weighs in at 60 pounds. "No big deal," you say? 60 pounds is a lot to pickup and hold for several minutes...or carry from a NFS potable water fill hydrant.

4 of these containers will essentially double your water supply, and it all can go into the fresh tank as you need it. Our rig has been out on NFS sites nearby for about 4 weeks. We don't run out of water.

Last point. If your rig carries a nominal 38 gallons, your hot water heater consumes 6 of those gallons...leaving you with 32. Then the plumbing in the rig will eat up another 1/2 gallon or more that won't be usable once the fresh tank runs dry and the pump is sucking air. Finally, it's likely that you'll have about 1 gallon or so that's not accessible just laying in the bottom of the tank but not making it to the pump...especially if you're not perfectly level. So you are starting with about 30 gallons of usable water. The rest is lost the the plumbing and hot water heater. 28 gallons in jugs essentially doubles your water supply for an extended stay.

I lied, that wasn't the last point. Here's another. Depending on where you are...such as the arid, fire-prone west...water is very precious. Grey (not black) water can be dumped into a bucket and toted away from your site 25 to 50 feet and used to "water the trees." This is NOT RV park behavior, nor is it appropriate near wetlands or bodies of water...or in super-saturated soils in rainy areas. But in most "wild" places, grey water is NOT contaminated enough to be hazardous to anything. The small amounts of food particles and coffee grounds will NOT attract bears (despite the wild imaginations of some), and the soaps in the water are "surfactants" that are actually used as soil amendments in agriculture and gardening and lawn care. Hell, they use Dawn to clean oil-contaminated wildlife after oil spills. So you can further extend your stay by dumping grey water and hauling in fresh water. Then your only limitation is the black tank.
(For the inevitable "bears, bears, bears" die hards: We've been camping in Rocky Mountain bear country since 2010...mostly in vulnerable pop-ups. We've had bears in our neighborhood at home often. We've never seen a bear in the wild, even if others report seeing them. Our grey water NEVER attracts bears. We keep our campsite clean and secure our food -- often inside our locked truck. We NEVER kept food inside the PUPS. Now we have a hard-side, and we do store food there. Bears DO NOT WANT YOUR GREY WATER. They DO want your pick-a-nick basket. Ask yourself. What do tent campers do with their grey water? Exactly!!)

But wait, there's more. A solution for a full black tank. https://smile.amazon.com/stores/page...d-44d6a62165bd
I have the 15 gallon version that I use to haul small loads to a nearby vault toilet (if available). I can lift about 10 gallons plus tank into the bed of my pickup and find a nearby vault toilet. As it happens, virtually all vault toilets have concrete floors with tapered openings to accept a matching tapered flange on the toilet seat. One need only jostle the seat a bit (wearing rubber gloves, of course), lift it out and dump down the now easily accessible opening through the vault toilet floor. (Check ordinances to be sure this is legal where you are.) With this, your black tank is no longer a barrier to length of stay. If you are a serious boondocker, you can get a jumbo tank, mount it in your truck bed, and use a macerator pump https://smile.amazon.com/Flojet-1855...587600&sr=8-23 to move effluent up into your truck-mounted tank. You need to do some serious homework and math (remember the weight of water) before you undertake this waste-handling measure, but many big tanks can be dumped easily right from the bed of your truck using the stinky slinky you have for regular blackwater dumping.

In short, if you can make adequate power, you need never come home.

[emm-dee]

Originally Posted by nomad297

While we do still use paper plates, my wife likes to buy bamboo plates and bowls in bulk quantities. They do cost more than paper products, but using bamboo instead of trees should be a good compromise for your wife.

EDIT: I forgot to mention that my wife also finds plates and bowls made form palm leaves.

Bruce

Not very fair enough taking food supply from the panda bears.

[5picker]

I just want to point out... 'some' R/Vs have a wet bay where valves need to be turned for the water source. Just turning on the pump may not provide water from the fresh tank. Some R/Vs don't have these valves... but... some do.

Not sure I read what configuration the OP has?