City water leaking into potable water tank

[Ron Hill]

Any ideas where fresh water for city water pressure could be dribbling into potable water tank , filling it causing it to spill out the vent , checked the diverter control does not seem to be leaking through it . I don't have any schematic material to know if there is another valve that might be leaking ?

[GlasNav]

Back feeding thru the water pump from the pressure side.

Either the check valve on the water pump intake is failing or there isn't one installed and the pump has started to bypass. Even though that isn't the system you are using the output side of the water pump is exposed to the city water pressure when your water system is pressurized.

[JRTJH]

Your water pump diaphragm serves as a "one way valve" to prevent water in the pressurized part of the trailer plumbing from leaking back through the water pump and into the tank.

Occasionally, well really quite frequently, a small piece of plastic from drilling the fresh water tank fitting holes will be drawn into the pump, foul the diaphragm and cause a backflow "leak" that fills the water tank when connected to city water. Other "trash" can also cause the same problem.

You might consider taking your water pump apart and checking/cleaning anything you find in the roller/diaphragm part of the pump head. It's a simple task, but pay attention to how you take it apart so you can reassemble it properly...

[JShort880]

Originally Posted by JRTJH

Your water pump diaphragm serves as a "one way valve" to prevent water in the pressurized part of the trailer plumbing from leaking back through the water pump and into the tank.

Occasionally, well really quite frequently, a small piece of plastic from drilling the fresh water tank fitting holes will be drawn into the pump, foul the diaphragm and cause a backflow "leak" that fills the water tank when connected to city water. Other "trash" can also cause the same problem.

You might consider taking your water pump apart and checking/cleaning anything you find in the roller/diaphragm part of the pump head. It's a simple task, but pay attention to how you take it apart so you can reassemble it properly...

^^^^^^ This. Had the same happen on mine. Good chance to use your water pump as well! Get all of that water out of your portable!

[dutchmensport]

100% agree with everyone else... it's backfeeding via the water pump.

[Martian]

Easiest fix is to put a check valve on the pressure side of the pump. This prevents backfeeding fron street water and does not inhibit pump use.

[JRTJH]

Originally Posted by Martian

Easiest fix is to put a check valve on the pressure side of the pump. This prevents backfeeding fron street water and does not inhibit pump use.

That's an "immediate fix", but thinking "outside the box" for a moment. If there's trash in the pump diaphragm cavity that is the root cause for the leakage, if you don't remove that trash, eventually it will cause further damage to the rubber diaphragm. That will eventually cause pump failure.

Wouldn't it be better to remove the trash and protect the pump internal components rather than allow the damage to continue to eventual failure??? One never knows when that failure might occur, but the probability that it'll happen when you least want it to happen (the Peter principle) could put you in a situation where you are in the middle of nowhere and the pump quits working, miles from any way to get a replacement.

Sure, putting a one way valve between the pump and the plumbing run will "fix the problem" and could be a "second measure" to prevent recurrence, but I'd still want to "fix the root cause".....

[NH_Bulldog]

After a similar issue when my trailer was new, I installed an inline filter on the suction side of the pump. 5 full camping seasons later and I am STILL catching debris….but my pump has not had any back-feeding issues since.

[GlasNav]

Originally Posted by NH_Bulldog

After a similar issue when my trailer was new, I installed an inline filter on the suction side of the pump. 5 full camping seasons later and I am STILL catching debris….but my pump has not had any back-feeding issues since.

I like that inline strainer idea, think I'm going to add one at the pump between the intake check valve and the antifreeze suction line. I added ball valves to isolate everything as necessary, what's one more piece of equipment crammed into the little bedside box!

[ObiRich]

Nobody has mentioned the easiest fix. If the check valve is being held open by a small piece of debris, simply turning off the city water and using the pump can dislodge it.

[apachewolf]

Had that happen several times on my Laredo. The dealer replaced the pump and later the check valve but it happened again. Finally I got them to get a brass check valve from ACE (about $ 10.00) at the time). Fixed the problem and have never had any leaks since.

Happy camping.

[wasielak]

I had the same problem--dealer installed an external in-line check valve and that did the trick!

[Indnryder]

Originally Posted by Ron Hill

Any ideas where fresh water for city water pressure could be dribbling into potable water tank , filling it causing it to spill out the vent , checked the diverter control does not seem to be leaking through it . I don't have any schematic material to know if there is another valve that might be leaking ?

Watching…….. Mine is doing the same thing and now I suspect that it filled the tank without my knowledge and subsequently caused some sort of failure while on the road with all that weight, behind the vent is now gushing out into the underbelly corplast….. no idea how to approach it for repair yet so beware of the potential……

[Indnryder]

Originally Posted by apachewolf

Had that happen several times on my Laredo. The dealer replaced the pump and later the check valve but it happened again. Finally I got them to get a brass check valve from ACE (about $ 10.00) at the time). Fixed the problem and have never had any leaks since.

Happy camping.

Did the check valve get installed between the water pump and freshwater tank?

[Indnryder]

Originally Posted by ObiRich

Nobody has mentioned the easiest fix. If the check valve is being held open by a small piece of debris, simply turning off the city water and using the pump can dislodge it.

Tried that, even exercised the city/ tank valve in the event it might be there