Community Forums

DrPhil · 04-09-2017, 06:51 PM

Does anyone know the true fresh water capacity of the above? Brochure says 105 gal, but using a garden hose water meter that I previously used on my old coach and found to be accurate, I get much less. First of all, there seems to be a few gallons (guessing 5 gal) still remaining in the tank after I 'fully' empty with the dump valve (and the water pump can't pick up much more useable water for the house after this point - maybe pumps a gallon or two before running dry). Using the 'auto-fill' feature (which I really like more and more), it will fill ~60-65 gallons to the tank beyond the 'fully' empty point. This is close to consistent with the 2/3 full limit with auto-fill. However I typically get only another 10-15 more gallons after this point (total of 70-75 gallons) before the tank overflow starts dumping water. Making matters worse, it seems that once the overflow starts dumping, siphon action actually pulls 5 gallons back out of the tank at this point for an actual on-board useable amount of 65-70 gallons - 35 shy of the stated capacity. At this point, I have found no way to thwart the siphon action short of stopping the fill just before it starts. Doubling the problem is that once I start rolling, the overflow will find a way to dump even more of the precious water from the fresh tank. Thoughts?

BBelanger · 04-09-2017, 06:58 PM

I agree with you Phil. My thoughts after 6 months is that there is enough water that I always fill one or the other tanks needing to dump before I run out of fresh. I'm probably not using the tanks to full capability but I can get three days, and squeeze a fourth out of the system dry camping. Of course it would always be better to be able to go farther than that.
Bill

DrPhil · 04-09-2017, 08:30 PM

Yes Bill, the gray/black capacity is a challenge too, but before i get to managing those tanks, I'm puzzled by the fresh water advertised capacity verses the apparent capacity. Do you (or others) have trouble with overflow valve siphon before the tank is completely full?

stang37 · 04-09-2017, 08:52 PM

I can't say it starts siphoning before full but I can tell you it will siphon a lot of water out after it starts. I loose about 20 gallons after it starts. I figured out how to minimize the siphoning. Once you reach the 3/4 full reading reduce the input rate and when you see a trickle out of the over flow tube stop! I can see the top of my tank and can verify if it is full no matter what the readout shows. Also sweeping left turns and abrupt stops will cause a loss of water.

Dutch Star Don · 04-09-2017, 08:57 PM

If you go to your pegboard and remove it, you can reach the overflow tube. I lengthened my overflow tube (so have many others) by adding a section and stuffing it higher up in the frame. This solved my siphoning and dumping water on turns.

**TonyDi** · 04-09-2017, 09:15 PM

I went to my overflow line and made a very small hole in it at the top. A siphon can't start with an "air leak"

DrPhil · 04-09-2017, 09:18 PM

Its kind of amazing what you find in this forum if you put your mind to it. Sorry for reposting a question that has been visited before. Here are three useful threads. Looks like i have another project!

http://www.irv2.com/forums/f103/fres...-301682-2.html
http://www.irv2.com/forums/f103/wate...be-302915.html
http://www.irv2.com/forums/f103/fres...or-298343.html

Dutch Star Don · 04-10-2017, 05:38 AM

Phil....Pretty much anything you find on your coach that is an issue or you think can be made better has been done by somebody. Even little things that you or someone else changes, is good to post so that we all see some better ideas and some good fixes to problems.

I'm an anal twit about making things simpler and better. I never could afford a hot rod, so my last two DP's have been my "hot rod". I like doing projects that make the camping experience easier and more enjoyable. I like fabricating stuff and can fix most mechanical things, but come here for help with the more technical electrical stuff. I got help just last week from several people with my Battery Monitor Kit (BMK) install.