Community Forums

Tire Guy · 10-03-2015, 08:54 PM

Pump will loose fresh water pressure and start pumping air when tank still has 17% filled. I have drained the tank and the gauge is ok, but shows empty with 12 gallons left in tank. This means the loss of pressure is with almost 30 gallons of water remaining in tank. I think I have a pick up problem or a cracked line in tank. Any other ideas?

757driver · 10-04-2015, 07:30 AM

Quote:

Originally Posted by Tire Guy

Pump will loose fresh water pressure and start pumping air when tank still has 17% filled. I have drained the tank and the gauge is ok, but shows empty with 12 gallons left in tank. This means the loss of pressure is with almost 30 gallons of water remaining in tank. I think I have a pick up problem or a cracked line in tank. Any other ideas?

Tire Guy,

Welcome to the Forum!

Let us know what model and year of your motorhome so the responses can be more meaningful.

brobox · 10-04-2015, 08:41 AM

Welcome to the forum. What Don said, need year and model, lots of changes each year. The main tank drain was changed in 2014 to in-front of the PS rear tire to be able to drain all of the water.

t55watson · 10-04-2015, 08:46 AM

I don't think cracked tank. Wtaer would drain down to level of the crack and you would see water on the ground.

stik · 10-04-2015, 08:55 AM

Quote:

Originally Posted by Tire Guy

Pump will loose fresh water pressure and start pumping air when tank still has 17% filled. I have drained the tank and the gauge is ok, but shows empty with 12 gallons left in tank. This means the loss of pressure is with almost 30 gallons of water remaining in tank. I think I have a pick up problem or a cracked line in tank. Any other ideas?

I think you are correct, either the pick-up tube doesn't go down far enough in the tank, or there is a crack at the lower end of the pick up tube that starts sucking air once the water level gets low enough and the crack is uncovered.

dpinvidic · 10-04-2015, 09:07 AM

Most tanks that I have seen just have a fitting at the bottom, sometime the water pump and the drain valve are from the same fitting.

A easy check us to tilt your rv in one direction at a time to see if the pumps starts to draw again. Your tank may not be level.

A possible fix is to move the pump input connection tk the drajn fitting.
Regards,
Dan

brobox · 10-04-2015, 09:21 AM

For those non-Entegra owners, there is a complete tank drain located on the opposite side of the MH from the regular tank drain. Many are not familiar where this drain is located as many dealers do not know......therefore they never tell the buyer.

two-niner · 10-04-2015, 10:48 AM

Brobox: Do you mean that before 2014 the fresh water tank could not be emptied by gravity alone? Serious question.

Ann n Gene · 10-04-2015, 10:52 AM

Yes, there has always been a low point drain on Entegras (I had 11-13-15 models).

2016 Cornerstone 45B
Formerly 2011 & 2013 Anthems and 2015 Cornerstone
2014 Lincoln MKT towed

rbr · 10-04-2015, 11:30 AM

I don't think OP is trying to drain his tank - he's trying to figure out why he can't use all the water in the tank by pumping into the coach. ?

As mentioned above, my pump's suction line comes straight out of the side of the tank. If OP's is the same, the problem is likely an air leak in the suction line or on the inlet of the pump allowing it to pull air in when the head in the tank is low.

chlrman · 10-04-2015, 11:55 AM

Tire Guy, I have the same "kind" of problem on our 15 Cornerstone. the suction line to the pump has a tee in it at that line goes to a vent or an overflow something like that. When you get the water level that low in the tank there is not enough head pressure on the water line and it is easier for the pump to suck air into the line. Have someone run the faucet inside the coach and watch it in the wet bay. we simply don't let our tank get this low any more. I have thought about cutting a valve into that line, but that is just one more thing to remember to open or close. Good luck, Robert

brobox · 10-04-2015, 11:58 AM

Ron, after re-reading the OP, I think you are correct. I miss read the post. I have run my tank down once and I also had, I think, a number in the teens when I started sucking air. There was just a little over an inch remaining in the tank and I figured that was normal so not to suck up sediments. I just refilled last night at 17%. By site, it was real close to where I started sucking air before. If this post would have been earlier I would have let the tank run down to check the number before mine started sucking air.

Tire Guy · 10-04-2015, 04:57 PM

Thanks for all of your responses.
I have a 2015 Entegra Aspire RBQ. Working out the bug and learning more about the coach. Your forum comments have been a great help. I'm going to check that vent tube, a valve could be the easiest fix. As it is I would have 70 gallons of fresh water to use. Yes, I have a a bottom drain and that's how I found out how much water I actually had left.
Thanks again and I'll post my results.

wmpbauer · 10-04-2015, 09:25 PM

On jacks (level...so to speak) my FW tank is good down to 22%. Then I'm sucking air. If I need to, I can tilt the coach and get a few more gallons, but the lesson is that while you have 100 gal tank, you can't use but about 75 gal. After that, you're sucking air because of the design of the pickup tube.

Just another undocumented feature. 😥😣

Pat Bauer, President
Entegra Coach Owners Association
2013 Aspire DEQ
Ford Edge