Community Forums

SuperMike · 12-17-2010, 02:32 AM

Ok people, here is a problem for you. When ever I fill my Winnie up with fresh water, I do it until it runs out of the overflow, as per instructions. The problem is that the overflow continues to run and drains the tank down to about one third, before it stops. The overflow is a hard pipe so I cannot take the end up above the water level to stop it. Any ideas how to sort this out ? Am I doing something wrong ? Thanks
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palehorse89 · 12-17-2010, 03:45 AM

Mike, there has to be a pipe that is on the inside of the tank going down to that 1/3 rd level. Can you see the over flow where it hooks to the tank? Can you take it apart there and investagate the plumbing? If not when i fill mine i can look in at the tank and see where the level is, if you can do this just shut off when close to the top. Mine just has a barbed fitting screwed into the top hole on the tank with the over fill line going down to the underside of the coach. Hope this helps ya out

mikron · 12-17-2010, 03:49 AM

Have you tried filling 3/4 of the way and see what happens then. By filling until the over flow is overflowing you are creating the syphoning affect. I don't understand why you would need to fill to overflowing. We only carry half a tank for use while driving.

SuperMike · 12-17-2010, 05:21 AM

Quote:

Originally Posted by mikron

Have you tried filling 3/4 of the way and see what happens then. By filling until the over flow is overflowing you are creating the syphoning affect. I don't understand why you would need to fill to overflowing. We only carry half a tank for use while driving.

Thank you for the replies so far. I fill right up simply because on this side of the pond, fully serviced pitches are few are far between. Most of the time when the water is gone I refill with an Auqaroll which holds 8 gallons and takes quite a few to fill up again. I can't see the tank at all so have no idea how much is in it except by looking at the gauge inside. I can only assume that in the manufacturing the overflow pipe goes right down into the tank and thus allows the syphoning effect. I might try adding a length of flexible hose on the end of the overflow to get the end above the tank to stop it running.

Cruzer · 12-17-2010, 06:16 AM

I had that on my old Suncruiser. The fix was to put in a trap on the vent pipe. I did this with 4 PVC elbows and some piping. I built a square, about 4-5" in size and inserted it into the vent line sio that the square stuck up above the existing vent line. That acted as a trap so that the air would break and prevent any siphoning action from happening. Unfortunately I didn't take any pictures and that RV is long gone. Hopefully my description works for you.

pkendzor · 12-17-2010, 06:29 AM

Easy Fix........... At the top of the tank where the overflow first exits the tank drill a 1/8 " hole in the overflow pipe or elbow. I did this on 4 other motorhomes over the years.

Paul

Cruzer · 12-17-2010, 06:32 AM

Of course if you leave the water on when filling until it runs out the vent you will get some water squirting out of that 1/8" hole as well.

KJINTF · 12-17-2010, 07:17 AM

Thanks for the suggestions
I have the very same issue in my rig
That "Fix" has been on my To Do List for some time
Sure hate loosing 1/4 of the tank before we get to our backwoods camp site

SuperMike · 12-17-2010, 07:31 AM

Thanks for the thoughts people. If you can, keep it coming.

pkendzor · 12-17-2010, 07:53 AM

Cruzer,

Good point. We did this modification on motorhomes that used the shore hose fitting to fill the fresh water tank. All of these had a minimum of a 1/2" overflow pipe and we drilled the hole as close as we could to the top of the pipe.

In all of the coaches the fresh water fill was restricted from the hose inlet down to a 3/8" supply hose to the fresh water tank. The overflow had no problem keeping up and no water squirted out of the hole.

I could see water squirting out if the fresh water tank is filled with an outside gravity fill or a pressurized fill line the same size or larger than the gravity overflow.

In that case I would probably have installed a tee in the top of the overflow line and installed a small vacuum break similar to the type used on residential hot water heating system lines.

Paul

SuperMike · 12-17-2010, 08:04 AM

Thats a thought, if I really slow down the fill that might be a simple fix, whilst we are away. (Going tommorrow morning for our first real trip) When we get back, I will hand the problem over to the dealer.

pkendzor · 12-17-2010, 08:18 AM

SuperMike,

Slowing down the fill might help, but you still need a vacuum break of some type.

I like Cruzers idea and wish he had a pic. I will head up the shop next week and try out that pvc box idea.

Cruzer...... I can visualize the 4 elbows making the box..... did you tee into and out of it to make the trap? Forgive me I'm old !

One of my next projects is to increase the size of my tank fill. It takes me longer to fill my fresh water tank than to fuel up and dump tanks.

Paul

Clay L · 12-17-2010, 10:09 AM

The Winnebago factory did the modification suggested by cruzer to my coach when I complained about losing water. The tank is shallow and water easily sloshes out when you drive. Getting the overflow above the top of the tank as much as possible will help a lot to prevent water from sloshing out.

Also if your fill rate is fast the air can't escape fast enough and the the tank expands. When you stop filling the tank contracts back to it's original size pushing water out.
Opening the gravity fill door adds some extra air relief.

The overflow fitting is spin welded to the top of the tank and the tube does not extend into the tank so siphoning isn't possible.

UltraKen · 12-17-2010, 11:40 AM

Easy solution if you have an outside faucet/shower. Just open the valve and it will drain down enough to break the syphon. No need to crawl around your bays doing plumbing or drilling holes.