Bob Jones

Hi Tom! I do have the Remco coming and if it has a check valve in place I will certainly use it and remove the new one. I did notice a restriction in flow with the new brass one I installed. I probably should have used a 3/4" full flow check valve and then stepped it down to 1/2 PEX to avoid the restriction. I can do that later as I appreciate FULL flow. Nevertheless, after all of this, I am realizing it's foolish not to have one installed since it's so common for the internal ones in the pump to fail. That way, you're not throwing out an otherwise good pump, and on top of that, if the water tank is self-filling then the pump is not part of the equation right off the bat. Your idea of using two valves to replace the city/water selector has merit. I would do it if I could come up with a way to do it cleanly, but as you mentioned, it would not look stock. I would be more inclined to go the distance and install a motorized valve so that I could control filling the fresh water tank from inside 🙂 (reason being is that my park has +/- 42 PSI so if the pump is used to augment the park pressure and bring it up to 60 then I have to refill the tank a fair amount which would be easier to do from inside). Back to the issue, and, I suspect the conclusion. It does *not* appear to be debris in the ball valve that is causing the issue. It *does* appear that the valve lever is not turning far enough to 100% stop the flow! On the valve body itself are two cast 'stoppers' to prevent the lever from turning too far in either direction. Also, on the handle itself are two stamped tabs that hit the cast stoppers on the valve. Basically, both are out of whack. Those stoppers are preventing the valve from fully closing and it appears this is what has led to this entire goose chase. (see pics) but basically I flattened the tabs on the lever so that it can be spun 360 degrees. This will make it easier to 'clean' possible debris through spinning the valve, but what I'm really after is being able to position the valve anywhere I like it, or, where it needs to be). As far as I'm concerned, the stops don't need to be there because you can easily hear the water flow and adjust accordingly. As installed, in the City position, the valve handle is straight up (0 degrees). It's looking like in order to actually close that valve I need the handle to be at roughly 10 degrees. How about that? Once I confirm overnight what the *exact* position is I will trace a line on the plastic housing using the lever as the ruler and then I can set it to the 'no leak' position with ease.. For the record, I did visually check the valve prior to installing it. It appeared to be high quality and there were 83 reviews on it, every one of which was 5 star. I could not get the valve locally from *anyone* even though in the US you can probably get them at the corner store! Up here, for whatever reason, plumbing outfits found it to be 'odd'. And...it needed to fit in the plastic case.

Thanks Ray - it is clean. Once the pump is properly placed it will be cleaner yet. The clear line teed into the drain is the pump intake. I put the check valve on the other side of the pump (you can see the brass in the picture) because this seems to be 'best practices' as it also could protect the pump. I think this is why Remco says to put it there in that document you so kindly posted. Btw, in the first pic, on the far right, you can see a white hose in a loop. That is the fresh water overfill line. At the very top of the fresh water tank is a fitting that hose is connected to. So when the tank is filled to the top, any more and it leaks out that hose. It used to be a straight line but I put a loop in it in the hopes of preventing the tank from draining while driving on an incline. Don't know yet if it will work or not. I just went out and checked the tank - it has been several hours now and it does *NOT* appear to be self-filling anymore. This was after removing the ball valve lever (the selector lever for city/fresh water) and rotating the ball valve 360 degrees several times. It's still early days, but if tomorrow the tank has *NOT* self-filled any more then I would say the issue is/was debris in the ball valve causing a minor leak. In my research, I found many posts from people with the same issue. When the pump check valve was excluded several people said they 'fixed' the City/Water valve by rapidly cycling it back and forth and also connecting it to high pressure. Their conclusion always came back to the same thing - debris in the ball valve. So what they were doing was trying to 'knock' it loose. If I am correct, and I think it may well be cased, a better solution is to remove the lever and rotate the valve several times 360 degrees. If there is debris in there, it would stand a much better chance of being knocked out by completely rotating the valve repeatedly. So far, so good. If my conclusion proves correct then I would suggest that *anyone* having this issue do two things, install a one-way check valve on the discharge side of the pump, and take the lever off the ball valve and use vice grips to rotate it several times. The nature of those ball valves is such that they really should last a lifetime. Keeping my fingers crossed but I think I got it beat.... Here's a picture of what I'm talking about. With the lever removed you can rotate that ball valve 360 degrees as many times as you like in the hopes that if there is debris stuck in it, it will flow out. Probably best to do this with the unit connected to an external water source and maybe with a tap open so that it has water flowing through it while you rotate it. This is what I did, with the idea being the debris will be carried away with the water.

No, that one is sealing. I also have another one at the start of the feed to the Swann valve so the stock one is redundant. Some encouraging news.....I took the lever off the Swann valve and then you can spin the ball valve 360 degrees. I rotated it two or three times, marked off the water line in the fresh water tank with masking tape and.....so far.....it does not appear to be self-filling. I will know more tomorrow morning after it sits overnight. IF I am successful we might have come up with a new way to combat this issue. IF there is debris in there causing the valve to leak, then removing the handle and rotating it several times may be the ideal way to clean out the debris. Darn tootin' Just wait until the new pump comes in and it's all mounted and cleaned up. That timer on the right (kind of cut off) is for the black tank flush. It works like a top. With the water pressure we have in the park, I set it to 17 minutes and it fills the tank for me.

Yup, the original issue is the fresh water tank self-over filling. As a result of researching all of this I realized that Monaco, in 2000 anyway, did not use a relay to power the pump and that there is massive voltage drop to the pump likely resulting in sub-par performance. That will be addressed as soon as my 30' of 10 AWG wire shows up (don't know how much I need, will run as short as possible for less voltage drop). There is now a check valve installed on the outlet of the pump. There is no way for water to backflow through the pump at this time. This leaves the new 3-way City/Water valve that I installed as the likely culprit. I will take the handle off the valve and then cycle it further (round in circles?) in the hopes that it might free up something if it's stuck in there. Barring that, I will have to remove it (again, 4th time) and then strip it down and inspect it. It is theoretically possible that the cast stop on the valve (see pic) that prevents the valve ever from turning further is not allowing the valve to close 100%. By removing the lever I can turn it further and see if it stops. Here's some pics to illustrate what the wet bay looks like. The pump will be relocated once the Remco shows up but for now it's ideal to have it lying there. BTW, installing the check valve did result in a restriction in the water flow. Perhaps the Remco will solve all of that.

Update: The one-way check valve came in today and I installed it on the outlet of the pump facing the correct way. I then filled the tank to 99% and waited. It's still leaking out the fresh water overflow 😞 That leaves the city/water selector valve. The one that I replaced with a lightly used one (from the hot water bypass) and it still leaked, and then, finally, with a brand new valve which also, evidently, leaks. Tomorrow I will file off a bit of the handle just in case the limiter on the valve is not letting it close all the way. I also found out, that on my unit, there is just shy of a 3v drop when the pump is running. Looking at the wiring diagram shows that the power feed to the pump does NOT go through a relay but is actually supplied through the switch on the KIB display in the vanity.....looking more closely shows that the factory used 12AWG to the KIB, then 14AWG to the wet bay switch, and then 12AWG to the pump connector. The pump I have now apparently can draw 10 amps. When watching it work, as it gets near the cutout pressure it labors a great deal and gets hot. RPM slows by a lot. I'm now thinking that as the pump gets near cut-out it's both working harder and starving for power. I find myself wondering if I put a relay in there, fed by 10AWG direct off the battery, if the the pump will then fly up to cut-out pressure without laboring any significant amount. I bet it will. In the meantime, I still have leaking water.

Thanks Tom! Lots of great info and sorry about the two threads. Here's how it presented; Everything was fine until a few months ago. Fresh water tank was not self-filling. When it started, a used City/Water valve was installed that was pirated from the hot water tank cut-off. Tank still self-filled. I then installed a NEW City/Water valve, a quality one, and same thing. Conclusion, it should NOT be the City/Water valve... The other day I installed a new pump to address the issue but, same thing. But...I used the same make/model/brand of pump. This is why I just upped the ante and went with a Remco (that, and the increased pressure/output). One bright light in here suggested installing a one-way check valve on the pump to stop it from backfilling, I have one on order and I think this is the smart move regardless of whether a person has an issue or not. I'd say it's 'best practices' to have one - period. That way the owner is *never* relying on the internal one in the pump. I DO have an accumulator installed, a large one and I also saw that Aquajet stated (on video) to bypass it, I think for the reasons you mentioned. I don't have the Intellitec controller, just two rocker switches, one by the vanity and one in the wet bay. They are not momentary. I will be installing a relay, if for no other reason than to ensure the power feed to the pump is well beyond requirements. I am re-locating the pump so that it can be serviced or adjusted in seconds, since I think I'm on my fourth? Point being, at this point I'm pulling out all the stops once and for all 🙂 and I want to be able to change pumps out in 5 minutes. I saw the reviews on Amazon for the Remco, and it does appear to be clear that they hate Amazon and will not warranty pumps bought from them. It also appears that many folks had problems with their pumps from Amazon and that led to people speculating Amazon is flogging reman or repaired pumps. Hard to say. It appears Remco *requires* you to send the pump back to the specific place you bought it from for warranty service. This is stupid since in the RV industry the client may have bought a new pump in Florida and found that it died in Seattle......I also saw that many people, even when bought according to Remco's wishes, had nothing but problems dealing with the company. It seemed that they just outright denied warranty claims at will all the time. My issue is that I'm up in Canada. So getting one at a reasonable price is very hard. As such, I went the Amazon route but what I did was spend the extra $15 for 3rd party two year insurance. I'm looking at it this way, I should know within the normal 30 day return window if the pump is junk. If not, then I'm covered for two years *outside* of Remco. In theory, if it lasts that long then it should be as good as can be expected? However, I was up at the local irrigation company today and happened to ask them if they sell Remco pumps thinking that might be a way to address possible warranty issues. They didn't. BUT they did sell 12v pumps and wow, did they have some beauties. Delevan FSB2 (also called the Fat Boy) which moves 7 (!!) GPM up to 100 PSI. Peak power draw is something like 35 amps (!!) I held it in my hands and looked at it, it was remarkable. It looks like a true industrial grade pump. When I bring the new power feed into the wet bay I will make sure I use some of the 10 AWG wire I have left over from the solar install just in case there are issues with the Amazon Remco. The price of the Delevan Fat Boy? $662 CAD about $521 USD plus taxes. The instructions refer to it as an RV pump.....and....you can buy parts from them for it. Exploded diagram complete with part numbers. It was one heck of an industrial pump that they refer to as an RV pump. Anyway, many thanks for the research you did, you nailed the issues I saw and added more that I didn't see and it's greatly appreciated. I'm certain this thread will help others in the future as well. I will update the thread with pictures as I go along. I do think the idea of having a check-valve installed should be mandatory since pumps, in general, often seem to have their internal ones fail causing an otherwise good pump to be chucked out. I'd sure like to hear if anyone has run the Delevan brand of pumps in their RV. They have smaller ones with less draw and price as well. All I can say is the FB I had in my hand looked like the last pump a person would ever need to buy, especially since all the pump parts are available. The electrical motor itself looked like a lifer, and then some. I've seen bench grinders with motors that did not look as heavy-duty as that one! Product-Brochure-FB2-Series.pdf

It was determined earlier in this thread that the check valve Monaco installs on the left side of the City/Fill valve is there to prevent your pressurized internal water system from going past the City/Fill valve and out the motorhome. Think of it like this, if you had no water supply hose connected to the City/Fill valve, and that check valve was not there, then when you turned on your water pump, water would come flying out the City/Fill Valve.

Now THAT is a smart idea !! I just ordered up another new pump. I'm going to see if that cases it just so that I know 100%. But now that you mention it, why not install one in-line anyway? I've had two pumps fail due to the check valve issue. I kept them. They were fine, other than that. If I had installed a check valve, as you suggested, I could have kept using them. I will do it once the new pump is in regardless of whether it fixes the issue or not. Many thanks for a very bright idea!

Yes, my original pump was mounted on the left wall of the wet bay near the floor. There were a lot of pex lines in that area and that made it nearly impossible to adjust the cut out pressure setting on the pump. I decided that if I'm going through the effort of retrofitting a non-exact replacement I might as well move the pump to the floor level and make it easy to replace/adjust. Awesome! I'm relocating it to the floor and I have a piece of stainless that I was going to bolt to the floor and I was already thinking of putting some rubber in between the stainless and the floor. I have long flexible water line going to it already so it's just a matter of customizing the lengths. I don't have a controller, but I do have two switches for the pump and apparently that adds a lot of power drain. Since I've gone this far I will likely run a new power feed from the battery to a relay and ensure it has more power than it draws. At that price, I want it to run at full speed. I do have an accumulator, it's about 3 gallons, as I recall, and it's new last year(?), it's not water logged. I'll adjust it according to the cut in on the new pump. My whole hope is that this ends the fresh water tank auto-filling when connected to city water. But....the shower could use more pressure and this pump should do that!

Hi Guys! My new water pump packed it in so I'm going to upgrade to the Remco Aqua-Jet ARV-55. I didn't really want to spend that much on a water pump 😞 I'm going to take the time to relocate it as well so that it's in an easy location so pumps can be changed quickly. I'm going to look into voltage drop to see if the stock pump wiring can handle it. Now would be a good time for everyone to tell me how much better my life will be with it installed 🙂

Well, I went out and moved the City/Water valve repeatedly. Snapping it back & forth at least 20 times and I still have water leaking out the fresh tank overfill. As mentioned, I had replaced the City/Water valve not long ago. It's a bit stiff to turn, in other words, like new. I think I'm going to try changing pump brands. New thread on retrofitting a Remco Aqua-Jet ARV-55 started. The new replacement pump is overheating much too easily. There appears to be something wrong with it (identical to my old one) so the old one will go back in for now.

You mean the check valves in the water pump, correct? This is the thing, I've replaced the pump twice now. Most recently, yesterday. The last one I replaced about a year ago. It *shouldn't* be a bad batch of pumps. Thank you for confirming my assumptions on that check valve. Because my brain was getting fried the obvious (now) fact hadn't occurred to me that when the pump is on of course the internal plumbing is pressurized and without that check valve water would flow back out to the city-water switch. You've eliminated that and I've learned something- thank you! Good thinking. I also seem to remember someone suggesting that some time back, now that you mention it. I will try that this morning. Unfortunately, the park does not have good water pressure, at most 42 PSI. It might be time for a 'road trip' over to my parents where they have ~100 PSI or so. Yes, there is *lots* of fancy plumbing inside, and I thought the same at one point, but it's not the cause 😞 If I were building up pressure to excessive levels I would see it on the pressure gage. But, to be sure, I've been testing with the hot water tank cold. In that case, it's the same as any other unit. I only have a single water spigot in the wet bay (hose bib?) and I have checked that as well.

Hi Guys! On my 2000 Diplomat I have a recent issue (over the last year) of the fresh water tank filling itself when connected to city water with the 2-way valve set to city water. Here's a pic of the valve so you know what kind of system I have. I realize this is a common problem and it usually has one of two sources, one, and the most common, is the check valves in the 12V water pump are leaking allowing water to flow back through the pump and into the fresh water tank. The second common issue is the two-way valve (city/water) is leaking and allowing water to flow into the tank. Since my pump was relatively new, I changed out the two-way valve with the one that was used on the hot water tank bypass (exact same valve). Now, of course, I'm replacing a used valve with another used valve but it was just easier for me than to source a new one. Problem persisted. At that point I ordered up a new valve and installed it. Problem persisted. I liked the pump I had and did not want to replace it so I just gave up and worked around it by turning off the fresh water at the pedestal. Fast forward to today and I ordered up a new 12v water pump, installed it, filled the fresh water tank very near the top and let it sit. Guess what? When I came home, water was coming out of the overflow for the fresh water tank. In other words, problem persisted! Just to recap, no less than 3 (total) fresh water valves replaced with the last one being brand new. Problem persisted Replaced the relatively new pump with another new pump today, and the problem persisted. Logically, at this point, either I am the unluckiest person in the world when it comes to 2-way valves or 12v pumps or....it's something else. The water pressure in this park is pretty low, max is 45 PSI and it's usually lower depending on resident's usage. If you take a look at the picture above, I'm assuming the left side of the valve is the outlet for city water and the right side is the fresh water tank. But there is a fitting on the left side of the 2-way valve. That fitting is a one-way check valve.....At this point my brain is fried but I am wondering if anyone knows *why* that check valve is there? I can't really see it being the problem but I don't understand what it's function is. Perhaps to prevent water from inside the unit flowing back out into the park? Perhaps they (Monaco) were thinking that a guy could somehow pressurize the water system in the RV above that which the park provides and then send some kind of contaminates back into the park water supply? So, my problem is, my water tank is still self-filling even when the 2-way valve is set to City and I don't know what that check valve is designed to do.

Isn't there a bypass valve on or about the hot water tank with a lever that you can activate?

^This. It's very easy to check with a voltmeter. I like to start at the top and work my way down. I'd check each panels output so you know how the system is wired etc. Very easy, pretty much can't screw it up 🙂 By the time you're done that quick check, you'll be fluent in it and know exactly where the issues are.

Amazon. The one that looks like this has been excellent. Made by 'Measureman' I've put it on feed lines with +110 PSI Liquid filled gage. 100% brass. No restriction. No leaks. Problem solved. . Exactly. The day I started out in the RV is the day I asked myself why the water flow was so bad inside. Turns out, Dad had put two of those inline water pressure reducers in the feed hose. Took them out and wow. What a difference. As my journey into plumbing progressed over the years I learned about full flow brass valves. I also learned about avoiding elbows with PEX fittings. You may think it it's not a big deal - it is. Just try removing that water tank bypass valve and see how much your flow improves.....Yes, that valve is a big restriction. There are more....

Excellent PDF and exploration of the issue. I am surprised that you can't just get a replacement from the heavy-duty trucking industry. I would have thought there would be millions of switches like that in service on the road that could be retrofitted.

Lots of good suggestions. If it's easy you could also dead end the output of the water pump by plugging off the discharge hose. (isolating the pump from the rest of the water system). What it should do is quickly rise to cut-out pressure and then stop running.

If the pump runs, pumps water, then that is what it is supposed to do. If you turn it off, and you are not connected to shore water, then you won't have any. This is also correct operation. So that leaves one thing.....when the pump runs it does not shut off. If you have a leak, it will not shut off, or, if a Fawcett is open etc. The only way it will shut off is when the entire water system gets up to pressure and holds it. Any leaks or bleed down and it will come on intermittently, or constantly, depending on how big the leak/usage is.

I'm wondering if it will be as hard as you think. Looks to me like you've already done most of the hard work. When I put in a new toilet I had to cut the large downpipe for some reason, it was no big deal at all. I also plumbed in a new black tank flushing system. While I didn't remove a tank I had it all apart like you do and maybe a little more. For me, the hardest part in the whole thing was removing the wet bay white metal panel. Everything was easy after that.

I'm not familiar with that pump but this one has been very good to me; Flow Max Water Pump for RVs It's inexpensive, well built, and I had two but sold my spare to my neighbor as her sure-flow packed it in. With respect to cycling, if you have an accumulator already in your system this should not be an issue. If you don't, then maybe one of those more expensive variable pumps might be in order. This one was a direct replacement on my 2000 Diplomat. So if the shoe fits, I'd wear it. EDIT: I just looked into your pump and it is the high end variable output design. My post will likely not apply.

So...be sure to check the check valve in the electric water pump because that can also cause a self-filling water tank.

Just an update to the original post. I've been helping the neighbor for the last few days try to get it sorted out. After many hours of fussing and fighting and calling I think we finally found out what happened. She's 72, a recent widow, and, typically, frightened of everything. What I mean to say is, she is alone and worried. So when her furnace made a bit of noise I mentioned to her it could be the motor, no big deal, but she should probably put a maintenance kit in it while in there. I explained how little they cost blah blah blah. I had done mine, no big deal. So, what does she do? Calls the insurance and opens a claim. Guy comes out, there was a small stick hitting the wheel making noise, $100 - done. But in the meantime, she opened a claim. It went nowhere, didn't cost the insurance company anything, but there's a record of it. So we asked for a list of all claims from them. Turns out, over 5 years, 4 claims, 3 of which went no-where (no monies paid) and one claim where insurance paid $363.64 Don't know why, her deductible was $1,000, but there you go. So the insurance company took in roughly $9,000 in premiums and paid out $363. In my mind, that makes her a golden customer. But...it seems they are looking at the number of times she is calling in determining that she may be an increased risk? Either way, we're now trying to get insurance from 2 other companies and so far....no luck. In my mind, it's ridiculous. I've now told her to stop calling the insurance company every time a pine cone falls on the roof and have tried to explain the cost/benefit analysis. Ie, if her deductible is $1,000, and the repair is, let's say $1,100 then you might not want to bother using insurance for that $100 savings.... Likewise, when her furnace made noise I told her not to worry, heck, a entire furnace is probably $750, less than her deductible. And that's in a worst-case scenario that would never happen. Nevertheless, she's on the phone to the insurance company when her deductible is $1,000..... She's in a tough spot and has a hard time understanding concepts anyway. So, not sure yet what will happen, but if she can't get insurance she will likely sell unit and move into apartment. I feel for her. The brokers just don't care other than one that I am working with. Not one person will listen to the story and treat her accordingly.

I had/have a similar issue. Water tank was self-filling. There's two common things that cause it, the check valve in the electric water pump is leaking/bypassing or the city/water valve is leaking. The check valve in my pump was fine. Regardless, I have a spare pump and replaced it. Still filling itself. So then I replaced the city/water valve with the one that was on the bypass for the hot water tank (same valve). Still leaked. OK, so I bought a new city/water valve and installed it. Same thing. After all that work, sometimes it leaks, sometimes it doesn't. So now when the tank is full I just shut off the water from the pedestal and wait for the fresh tank to get down to the bottom before turning the city water back on and let it self-fill over a few days. Wish I could give you an answer that actually worked.

I removed them all some time ago due to the difficulties they seem to create. Ditto 🙂