Winter plumbing mod

[D&D]

So, I bought a 2005 Sportsmobile EB50 over Christmas/New Years and took it camping for a week or so in Death Valley. It got below freezing overnight, which taught me a few things:

1) You have to open the drain valve under the city water inlet connection to drain the water out of the PEX pipe that runs under the van (this should, theoretically, be the only piping outside of the insulation).

2) You then have to close this valve. Otherwise, when you turn the pump on, it'll pressurize the system, send water back down this pipe, and shooting out the drain valve.

3) Which means that you have to (annoyingly) get in and out of the van every time you want to run the faucet (so that you can close the drain valve, run the water, then re-open the valve to drain the water again).

I don't see myself ever leaving my Sportsmobile "plugged in" to city water -- so this is strictly a fill port for me, which is a purpose also served by the internal fill port. Since one of my primary goals of owning a Sportsmobile is winter camping, I plan to use the interior fill port almost exclusively.

So, in order to keep the drain valve open (and the exterior PEX pipes clear), I decided to install a ball valve right where the PEX pipe enters the van from the bottom. This way, if the ball valve is closed and I turn on the water pump, water won't go shooting back out the drain valve.

Here are some pictures --

Step 1: gather supplies.



From left to right -- 1/2" Sharkbite push-to-fit elbow joint, Milwaukee pipe cutter, 1/2" sharkbite push-to-fit ball valve, wire cutter, Sharkbite deburring tool, Sharpie, and some zipties.

Step 2: disconnect the gray tank. This connection is on the passenger side rear wheel well.



Step 3: drop the gray tank, which is just rear of the rear axle.





Step 4: locate where the PEX pipe from the city water inlet port enters the van (mine was just to the rear of the gray tank, right above a crossmember)

In the pic below, it's the long white tube that enters the van. The stubby tube next to it (poking out from the van bottom, pointed straight down) is to drain the fresh water tanks.


Here's another pic of it, for some frame of reference


And a close-up


Step 5: cut the PEX tubing about 3" from where it enters the van



Step 6: push on the push-to-fit elbow and ball valve




Step 7: reinstall gray tank

In the image below, you can now see the ball valve sitting above the crossmember. In the summer, I can just crawl underneath, and open up this ball valve when there is no danger of freezing.




Then you're DONE! Pretty easy mod. Only non-ideal thing is that there is obviously still a ~6" length of PEX pipe/elbow/ball valve where water can (and will) freeze. Ideally, the ball valve would be installed inside -- but the way my plumbing is on the inside didn't have space without a major re-routing of all the plumbing. I'll probably do that in the near future, but this is a stop-gap measure that should get me through at least this winter.

I'm also going to add ball valves to 'lock out' the cold and hot water heading over the back door to the shower (interior and exterior). That's an area where a bunch of water currently gets wasted due to pipe fill, and can be one less freeze area if I keep it dry.

[DCHitt]

It does take a lot of attention to detail if you want to use your fresh water tank in the cold weather. My pipes are all inside except for a fill pipe similar to yours. Sportsmobile did put a valve on the inside that allows me to shut off the outside fill line so I did not have to add one.

Just like you I can open the drain below the fill connection but I have to blow into the fill hose to get all the water out.

I live in the North East where it is freezing right now and I leave water in the van year around.

[D&D]

Yeah, it does take a lot of thought to properly use this stuff in winter. It almost seems as though Sportsmobile just shrunk down the plumbing system of a normal RV instead of re-thinking this kind of thing for a much smaller, overlanding-focused vehicle.

Things they did right:
+ PEX plumbing throughout. This is good. PEX is supposed to survive several freeze/thaw cycles due to its flexibility/expansion (although I still think you want to avoid it as much as possible).
+ Flat-plate heat exchanger makes a ton of sense vs. a tank heater
+ Gray water tank location is a great use of dead space under the EB50

Things I'd do differently:
- They've plumbed the whole thing to run off a city water connection, which introduces all kinds of complexity, and outside plumbing. Does anyone actually leave a Sportsmobile plugged into a city water connection? I'd just use the interior fill port and only allow the van to run off its own tanks, thereby eliminating any outside plumbing altogether.
- In several places, the plumbing runs behind the walls. As BadgerTrek has pointed out, this is often OUTSIDE the insulation despite what they say. Why ever run plumbing behind the walls? Makes it impossible to repair/inspect/etc. I'd run all of it inside furniture, but not inside the walls.
- The pump/tanks/plumbing/etc under the seat is a maddening system of knobs and valves. Complexity is the enemy of reliability.
- Like BadgerTrek, I'd run the heat exchanger inside the van vs. outside -- otherwise, in a good freeze, it'll rupture from freezing water (unless you drain it).
- There really should be "one place" where you can open a valve and drain the entire system, without messing with compressed air every time you want to properly winterize. Haven't sketched it out, but I guarantee it's doable if you put thought to it.

[skoronesa]

As a plumber, those sharkbite fittings are giving me a headache, nevermind the tension the joint is under.....did you at least use the little white inserts that stiffen the pex before you put it into the sharkbite fitting? That back pitched sharkbite elbow will hold water and may freeze/crack. For future refence Fostapex piping is pex with an additonal layer of aluminim/plastic and stands up to freezing even better than regular pex which is usually pretty good with freezing. Not to mention it doesn't get chewed through by rodents.

[D&D]

All good points -- I'll see how this stuff holds up. Good news is that it's on the outside, so if there's a leak, it's not a huge deal. The Fostapex sounds like a good idea.