brocki Report post Posted July 2, 2018 Was having classic symptoms of water pump check valve failure with original water pump. Symptoms were pump running intermittently with no water being used and when on city water, fresh water tank GAINING about 50 % water overnight. So I went to my trusty parts store and bought a Shurflo model 4008-101-E65 replacement. Hooked it up, no problem. Now the problem. I am still getting some intermittent running of the pump with no water used and when on city water it still filled the fresh tank about 1/4 tank overnight. So let me ask all of you: 1 Have any of you gotten faulty pumps out of the box of this model 2 The only other possible cause of this leakage might be through the manual selection valve that directs city water to the tank. But I know of no way to test that theory and I admit it is a stretch. Collective knowledge please. Share this post Link to post Share on other sites
desertdeals69 Report post Posted July 2, 2018 I think you have a valve problem. I would guess your old pump was ok and was just running because the fill valve is not closed tight. I just put in a new Shur Flo pump and it works fine. Share this post Link to post Share on other sites
kaypsmith Report post Posted July 2, 2018 21 minutes ago, brocki said: 1 Have any of you gotten faulty pumps out of the box Yes to that part of the question that I quoted, but no to that model. Now to address the rest of the question, you stated that the old one leaked 50%, and now the new one 1/4 (25%), so it would be strange that replacing the pump only slowed down and did not stop. It does seem as if both pumps were by-passing, or flowing back the check valve on either pump IMHO. Do you have a pressure limiting device on your coach? If so what pressure is it set to, or is it one that is preset? The checkvalve that is built into these pumps are no more than a rubber diaphragm and over pressure from the fresh water system can cause them to leak backward. I personally prefer to add a good quality checkvalve into the plumbing just after the pump. Remembering that the arrow (flow direction) is pointed away from the pump. Inline checkvalves can be purchased at any plumbing supply, or most building supply box stores, very inexpensive. Question #2, it is possible that the manual valve is failing, but does seem unlikely since two different pumps, and this is still occurring. You could remove the line from from the valve to the tank and let it drip into another container, if that puts water into another container, then that probably is the problem. I was slow typing, so DD69 got ahead of me, sorry for the redundancy. Share this post Link to post Share on other sites
hermanmullins Report post Posted July 2, 2018 Until you get a new inline check valve, which is your problem, fill your water tank and just use the pump. I am willing to bet if you do that you won't have the pump coming on intermittently. IMHO Herman Share this post Link to post Share on other sites
richard5933 Report post Posted July 2, 2018 Do you have a good filter between the tank and the pump? One of the things that can caused the pump seals (check valve) to leak is floating debris. It could be sand particles, it could be scaling from hard water, it could be rust particles, etc. The reason I'm going down this path is that perhaps whatever caused your first pump to fail is still there, and possible made worse by changing the pumps when you were moving the pipes/tubes to install the new one. Our coach had very little use when we got it, but the hard water build-up in some places was quite visible and flaked off easily when I replaced our pump. As a side note, I just purchased an extra-long drinking-water-safe hose that will allow me to fill our water tank from the house faucet, since that faucet is fed by softened water. It won't eliminate all problems, but for most smaller trips we don't have to refill and can avoid using hard water. Hoping to minimize hard water scale as much as possible. Share this post Link to post Share on other sites
wolfe10 Report post Posted July 2, 2018 If two pumps show the same symptoms, probability is that there is another cause. And, yes, the selector valve/tank fill valve may not be shutting off completely and/or could have chunk of mineral caught in it. You loose nothing by repeatedly opening and closing the valve to see if it can re-seal. Share this post Link to post Share on other sites
manholt Report post Posted July 2, 2018 Brett. Ditto...........Been there! Mine was a plastic ball valve on 3 different coach's. Replaced with brass....no more problems! Kay. Yes, too much pressure. Share this post Link to post Share on other sites
brocki Report post Posted July 2, 2018 Let me try to answer some of your observations. I have a regulator but as this house that is my water source is only about 40 psi, I'm not using it. I do have a whole house filter up-stream of the pump and tank. I change the element twice a year just on GP. As it took a while for me to get to this little project, we were filling the tank and operating off of our tank in both cases, old and new pump. In both cases, the pump continued to run with no outside source attached. This is the first time that the OEM piping has had to be disturbed so I can't verify if any scale got lose but beside a new pump, I also installed a new screen. Admittedly that only gets the large chunks, but nothing is visible. Though I have made sure the valve is turned all the way, I will try swinging the valve handle a few times and see if that corrects the problem. Sounds to me like I need to upgrade the quality of replacement parts we purchase, but that additional check valve is a good suggestion. I will update in coupe of days when I can get a check valve and some PEX fittings. That should settle it one way or the other. Share this post Link to post Share on other sites
desertdeals69 Report post Posted July 3, 2018 The check valve is located just after the incoming hose from the spigot. It prevents the system from back flowing into the hose when it is disconnected from the spigot and the water pump is on. If the valve is bad water will flow out the hose. Share this post Link to post Share on other sites
wolfe10 Report post Posted July 3, 2018 Likely talking about two different valves here. The check/anti-siphon valve where you connect the shore water hose CAN leak. But, it will leak into the wet bay, not into the potable water tank. The other valve is the selector valve (lots of different locations in different coaches) that allows you to fill or cut off water to the potable water tank. If it fails to close completely, it CAN allow shore water to fill the potable tank and/or allow pump pressure to "recirculate". Share this post Link to post Share on other sites
desertdeals69 Report post Posted July 3, 2018 I was referring to a check valve as mentioned by the op and clarifying the function of the check valve. Share this post Link to post Share on other sites
wolfe10 Report post Posted July 3, 2018 Yup, more than one valve being discussed in this thread. That is why I pointed it out. Share this post Link to post Share on other sites
kaypsmith Report post Posted July 3, 2018 The checkvalve that I am referring to is an add on, it is placed after the pump to keep backpressure off the pump, if the plumbing is pex, there are pex checkvalves that only need to cut the pex line after the pump, make sure the arrow is pointed away from the pump. This will keep any back pressure from the coach plumbing back to and through the pump, thus eliminating any excess pressure on the pump. This way the very pitiful checkvalves that are made into the pump do not need to over exert themselves from trying to keep back the over pressure which in many cases happen because there either isn't a pressure regulator, or it is faulty. I've used this method more than 30 years, and never had a problem with a pump allowing backflow to the tank. Yes I have lost pumps because of them just wearing out, but no fresh water tank over flowing while on shore water. And switching valves can certainly go bad causing the tank to overflow, but turning off the shore water will surely stop this. If the method that I described is used and the pump cycles, there is a leak somewhere that needs to be found. I once saw a unit that had such a leak, the owner didn't believe that there was one, he just kept replacing pumps, a year later he was replacing plywood flooring that showed where the leaking water was puddling. By the way the pex (sharkbite, gatorbite or whatever brand), fittings need only to make sure that the cut is clean, and burr free, they are push in style and rely on an o-ring to seal. Share this post Link to post Share on other sites
bh2oman Report post Posted July 4, 2018 If sand or debris gets into the butterfly valve, water from the city will seep past it and fill the tank. There are two - one is the pressure sensor switch. This will happen - not much you can do to prevent it. You can install a PVC ball valve on the input side. That way you can shut off the water to the tank and that will prevent it from filling. I would also install a switch on the pump so it can't be turned on when the valve is closed. Don't forget or you won't have water when not connected to city water. Share this post Link to post Share on other sites
brocki Report post Posted July 9, 2018 Wolfe, you nailed it. I took the screen assembly off of the suction side of the pump leaving both fittings open, made sure the selector valve was in the "city water" position and turned on the city water. It was either going to leak BACK through the pump/check valve assembly or bleed down the suction hose which is the same line to the tank. Bingo! After a little while, I got a trickle of water coming out of that open fitting on the suction line. Will have to replace that valve. Not sure I want to tackle that project. Getting to that valve is going to mean taking the whole plumbing bay face panel off. Just may farm that out. Thanks all for the good advise. I still am thinking about adding an additional check valve down stream of the pump. Later Gators. Share this post Link to post Share on other sites
kaypsmith Report post Posted July 9, 2018 Adding a checkvalve after the pump will stop that problem, very easy fix. Share this post Link to post Share on other sites
brocki Report post Posted July 10, 2018 On 7/9/2018 at 7:14 AM, kaypsmith said: Adding a checkvalve after the pump will stop that problem, very easy fix. Not really. In my case, the water came not through the pump but from the other direction, through the 3 way valve even though it was in the other position. It did not feed back through the pump. The pump's check valve did not leak. Share this post Link to post Share on other sites
kaypsmith Report post Posted July 11, 2018 On 7/8/2018 at 9:31 PM, brocki said: It was either going to leak BACK through the pump/check valve assembly or bleed down the suction hose which is the same line to the tank. Bingo! After a little while, I got a trickle of water coming out of that open fitting on the suction line. Will have to replace that valve. Not sure I want to tackle that OK, I Misinterpreted what you wrote, but I thought that the suction hose was the pump pickup hose, and the hose from shore water to the tank was a pressure hose. A ballcock valve in that line should do the trick if you are not ready to tackle the three way valve yet. Good luck and glad that you found the culprit. Share this post Link to post Share on other sites
manholt Report post Posted July 11, 2018 A separate ball valve in the inn line works great....just got to remember to turn it on, for city and off for fresh tank! Share this post Link to post Share on other sites
brocki Report post Posted July 12, 2018 On 7/11/2018 at 7:25 AM, manholt said: A separate ball valve in the inn line works great....just got to remember to turn it on, for city and off for fresh tank! Or just replace the faulty valve. It lived for over 10 years so no complaints here. Share this post Link to post Share on other sites
