Community Forums

tk369 · 01-24-2019, 09:48 AM

Hello.
My rig is a 2008 Coachmen FX-26, class C, Ford E-450, V-10, tuned.

When i fill my onboard water, I fill until the water comes out the overflow underneath. I turn off the faucet, and the overflow continues until the tanks are 2/3 full. The overflow doesn’t START until the tanks are full, but then continues.
Has anyone else experienced this? Anybody have any ideas? I am camping for about a week.

bst24351 · 01-24-2019, 09:55 AM

maybe try to over fill it. I'm thinking you might be causing a siphon affect

AFChap · 01-24-2019, 09:59 AM

Quote:

Originally Posted by tk369

Hello.
My rig is a 2008 Coachmen FX-26, class C, Ford E-450, V-10, tuned.

When i fill my onboard water, I fill until the water comes out the overflow underneath. I turn off the faucet, and the overflow continues until the tanks are 2/3 full. ..

Mine has done that. You have to stop the siphon effect. I can easily do that by pulling the fresh water dump valve for about 20 seconds. If you don't have a fresh water dump I don't know how you would do it.

Old-Biscuit · 01-24-2019, 11:45 AM

Got access to top of tank/overflow line?
IF YES---drill 3/16" hole in top area of line-----will break the siphon

If NO.....install a shutoff valve on overflow.
S/B 1/2" PEX so a 'sharkbite' valve will just press on end of line.
Easy installation

Post a note at fill to open/close valve!!!

Healeyman · 01-24-2019, 02:40 PM

Quote:

Originally Posted by tk369

Has anyone else experienced this? Anybody have any ideas?

tk,

I have had 2 Coachmen Freelanders. A 28QB previously and a 29QB now. Both had the 50 gallon water tank under the bed in the back.

BOTH have acted the way you describe when filling to overflow.

On my tanks, there is a screw-in plug in the top, front, drivers side corner of the tank. I unscrewed the square head plug and screwed in a check-valve like THIS one = https://www.amazon.com/dp/B000WR50VA...548365586&sr=1

The check valve will allow air to flow INTO the tank to break the vacuum, but will not let water flow OUT of the tank when filling to overflow.

The valve at that link is NOT the exact one I used, but it is similar. IF you go that route, make sure that the check-valve flows in the correct direction for your use.

Tim

Damion · 01-24-2019, 02:51 PM

I drilled and taped a 3/16 hole in overflow next to the tank and attached a 1/8" hose and a loop to break the siphon!

winniman · 01-24-2019, 06:58 PM

Turn on the pump, and open a tap and get it running. If the pump is drawing water out of the tank, it has to draw air in through the vent, which should stop it from siphoning out.

tk369 · 01-24-2019, 07:41 PM

Quote:

Originally Posted by winniman

Turn on the pump, and open a tap and get it running. If the pump is drawing water out of the tank, it has to draw air in through the vent, which should stop it from siphoning out.

will try tomorrow. thanks!
tk369

THenne1713 · 01-24-2019, 11:35 PM

SORRY to say, you or PO MAY have split/ cracked the tank? (My book) says to NEVER walk away/ NEVER fill to Overflow BECAUSE you risk rupturing tank if supply is greater than overflow and pressurizes tank. ; Recommended is to fill using the Onboard indicator lights; on mine, I can monitor tank level in the pump compartment.

Quote:

Originally Posted by tk369

Hello.
My rig is a 2008 Coachmen FX-26, class C, Ford E-450, V-10, tuned.

When i fill my onboard water, I fill until the water comes out the overflow underneath. I turn off the faucet, and the overflow continues until the tanks are 2/3 full. The overflow doesn’t START until the tanks are full, but then continues.
Has anyone else experienced this? Anybody have any ideas? I am camping for about a week.

ThePowells · 01-25-2019, 01:17 AM

If the vent tube opening in the tank is at a point that it would siphon out water from full down to 2/3, then once the water level goes over 2/3, then the internal pressure in the tank would build from the volume of water replacing air and begin pushing water out of the vent at that point.
I think that the OP needs to visually see his tank and see what is actually going on. It may be that the design limits the water level to that point, or his tank level sensors are inaccurate as usual.

Damion · 01-26-2019, 08:31 AM

Quote:

Originally Posted by ThePowells

If the vent tube opening in the tank is at a point that it would siphon out water from full down to 2/3, then once the water level goes over 2/3, then the internal pressure in the tank would build from the volume of water replacing air and begin pushing water out of the vent at that point.
I think that the OP needs to visually see his tank and see what is actually going on. It may be that the design limits the water level to that point, or his tank level sensors are inaccurate as usual.

My tank did the very same as the OP's.
It would siphon out the top 1/3 of the tank, it actually collapse the tank down about 1/3 and I can see it do it! Drilling the hole for a siphon break solved the issue.