Location of black and grey tanks

[Rkeithk]

I have a 2012 Montana 3750FL that I pull with a 2011 Ford F350. I really like this unit but I do have a problem, or I think I do. The location of the black, grey and fresh water tanks have me puzzled. Is there a website that can give the schematics or the location of each tank. Also I think that my black and grey tank valves may be mislabeled, as you look at them the grey is on the left and black is on the right, could someone that has the same unit advise me on this. This is my first post and have enjoyed and learned a lot, because this is all new to me.

[Festus2]

While I don't have a Montana, the two problems that you mentioned are not uncommon. Keystone does not provide a schematic for anything - wiring or plumbing - including locations of the holding tanks. I doubt whether or not you could find their location anywhere on the web.

Your FW tank should be very close to your kitchen sink and perhaps your water pump. One of your grey tanks (galley) should be in this vicinity as well. Your black holding tank should be located directly below your toilet. The other grey holding tank for your shower and bathroom sink should also be in that general area..

If you are ambitious, you can crawl underneath your unit, remove a few screws that hold the black plastic coroplast in place, pull down on the coreplast and peek in using a flashlight. You should be able to spot your tanks this way. It might take a few attempts before you can find where each one is located.

You are not alone in discovering that your pull valves have been labelled incorrectly. If you pour a bucket "coloured water" into the toilet and open one of the valves, you can eliminate one or the other as being the right one for the black tank. (Don't do this unless you have emptied your holding tanks beforehand!!)

Welcome, BTW to our forum and don't hesitate to ask questions as the need arises. Just find the appropriate category and ask.

[Rkeithk]

Thanks for the info, I will do just that. I am learning as I read the different posts.

[DocData757]

I have 2 grey tanks and when I got my Alpine, they were both just labeled 'grey' with no indication of which was the bath tank and which was the galley. I close both valves and ran the kitchen sink faucet for a quite a while. From this I could tell which indicator on my tank meter was which grey tank. Then I opened the valves one at a time. The one that got the big rush of water I marked with a 'G' for Galley and make the other 'B' for bath. My black tank was labeled correctly.

[chuck&gail]

Also black tank normally has pipe, and valve, almost twice the diameter of gray tank.

[SteveC7010]

Gray tanks will usually have 1.5" drain lines and valves. Black tanks will have 3" valves and drain pipes. They usually (but not always all come together at some point and empty out of a 3" drain fitting.

Sometimes, depending on the lay out of the trailer, the forward tank is daisy chained to the next one.

Now, this is not hard and fast, but it gives some idea of where to look to verify tanks. The black tank is almost always directly under the toilet. In travel trailers where the distance from the bottom of the toilet to the top of the tank is only a couple of inches, you should be able to look down into the tank when the toilet flap is open.

In fifth wheel units, sometimes the drain pipe is straight and sometimes it has a couple of bends in it. Regardless, the drain pipe is always 3" and the toilet should be above the black tank.

My Cougar has a shower and bathroom sink forward of the toilet. The kitchen is much farther to the rear. So, presuming that the black tank is more or less directly above the black, it is a reasonable assumption that the shower gray tank is further to the front. Standing by the dump port, from left to right it's gray shower, black, gray kitchen.

Since most Keystones seem to have the enclosed belly, my advice is to get out a nut driver and pull a few screws and look up in there with a flashlight and verify this. If you are not familiar with these things, it is even more important to see them and begin to understand them.

Our RV's are a bit different from our homes. Typically, we run a faucet or use a toilet without really thinking about where things go and such. In an RV, we owners need to understand these holding tank systems well. Otherwise, we have problems that can be very difficult to deal with once they've happened.

[SteveC7010]

I have a 2012 Montana 3750FL

snip for brevity.


One more point. Since you bought a brand new trailer, your dealer should have gone over some of this in great detail, particularly if he thought that you might not be familiar with RV plumbing systems.

[azlee56]

another thing through the walk thru that wasn't told to us.

[SteveC7010]

another thing through the walk thru that wasn't told to us.

Sadly, we seem to be hearing a lot of this here on the forum.

I think I could make a lot of money by starting up a school for new RV owners.