One last try

LauraRey

Hi folks, 

I’ve had a water problem in the TaB since last fall.  The pump is fine and I’ve tested it by attaching a hose to it and watched it drain a bucket of water quickly.  There is nothing in the filter. I pulled it and checked.  The system holds prime, so not a slow air link.

If I turn the water on, I get five seconds of pressurized water flow and then it becomes the tiniest trickle.

Jill and Dale worked with me last fall, but we never got it working.  (They are both amazing people.)

There is either debrie in the fresh water tank
or ....  could the stack vent (if it were plugged) cause this problem?

I really don’t want to take it in, but am running out of ideas.  Any thoughts you have would be greatly appreciated.

Here is a video showing the problem:  https://youtu.be/3uMXiWu-GnM

thanks, 
Laura

ScottG

The stack vent (part of the drain system) should not impact the flow from the faucets in any way. However...

There's a vent tube that allows air into the FW tank. On my 2015 it's a clear tube that runs from the top of the tank and follows the filler tube up through the T@B and to the fill port, where it exits at a small hole just above the larger hole you pour water into.

It's a small tube, and the routing and attachment of it is such that it could get pinched or kinked along the way. If this occurs--or if the tube is plugged--it could create a temporary suction in the tank and cause the symptoms you describe.

You might try taking another piece of clean tubing, pressing it tightly over that little hole, and blowing in it. You should be able to force air into the tank with minimal effort. If there's significant resistance, I'd inspect the entire line for blockages.

(Blockages in this tube can also make filling the tank difficult as there is no way for the displaced air to easily escape.)

No guarantees that's your problem, but it's worth checking.
 

LauraRey

Thanks Scott...it’s certainly worth a try.

Dalehelman

I think you may have a blockage in the Fresh water supply line to the pump. Disconnect the hose from the “IN” side of the pump. Try blowing or use compressed air back through the hose back into the water tank. You can also remove the hose to check for a clog. I am almost positive there is a blockage in the supply line, Also make sure the hose is not linked or  collapsed in any way. Is that the only faucet that is effected?

jkjenn

I would contact nuCamp repairs or warranty, whichever is most applicable.

LauraRey

@Dalehelman  I hooked up my air pump and blew air into it from the end of the hose that connects to the filter.  I could hear it bubbling through.  So, it may be a partial blockage.  I may try to run a ascope down the line.

Subism

Sounds like how my issue with the drain screw on the mixer valve started. The screw was loose and had a very slight leak that allowed the pump to build pressure, but once I turned on the faucet the pressure dropped rapidly and I ended up with very little water. Once the leak got big enough the pump would continue to run and never was able to build up pressure. I would check all the lines and fittings that you can see, as well as under the trailer for any sign of leaking water.

LauraRey

@Dalehelman  finally got a scope part way down the intake into the fresh water tank.  I did find some signs of mild/ mildew so I’m wondering if I have some in the tank itself. (Yes, I did sanitize it last year.) I’m draining the tank now and will do a couple of rounds of sanitizing tomorrow. I think I will probably try the ice cube trick as well and drive it around the block a few times.

@ScottG also checked your suggestion....it seems clear. Thanks

Dalehelman

Subism said:

Sounds like how my issue with the drain screw on the mixer valve started. The screw was loose and had a very slight leak that allowed the pump to build pressure, but once I turned on the faucet the pressure dropped rapidly and I ended up with very little water. Once the leak got big enough the pump would continue to run and never was able to build up pressure. I would check all the lines and fittings that you can see, as well as under the trailer for any sign of leaking water.

Second this possibility. Our 2015 doesn’t have the mixing valve.

LauraRey

@Subism. Is that the valve back by the Alde?  The one that mixes hot and cold?

Subism

@LauraRey: Yes, that is the valve where I had the leak; it was coming from a small silver screw on the side of the valve that I simply tightened with a philips head screwdriver. This would be a good place to look, but if you don't find the mixing valve to be leaking be sure to look around at all the lines/connections that you can see (by the Alde, under the driver's side bench, under the sink, back of the toilet) and also under the trailer just to be safe. Feel for any wet spots, as sometimes a small leak is hard to spot. You will typically find leaks at connections/loose fittings and where the lines may rub against each other, hold down clamps, or go through holes in the structure. If it is a leak and it gets bigger the pump won't stop running and you will still have no water pressure. Hopefully this is not your issue, but, then again, a leak is typically easy to fix.

FYI, here is a post on the drain screw leakage with good pictures from @BrianZ, who had the same issue: http://tabforum.nucamprv.com/#/discussion/6811/need-help-mixing-valve-leaking

Good luck!
Marc

LauraRey

@Subism it was fine.  The screw was very tight.  Thanks though for raising the possibility.

BrianZ

How about the outside shower faucet - can that on/off lever get stuck in the on position & might that create symptoms of a leak?  It has always seemed kind of "fiddley" to me when you have to pull to shut off after squeezing to turn on.

LauraRey

Ok, I also checked all the hoses and there are no kinks.  So, having ruled out all other options, I’m disinfecting the fresh water tank.  I’ll let it sit for six hours, drain part of it, toss in some crushed ice, and then drive around to see if I can dislodge anything that is potentially blockIng the flow.  

I appreciate your your help and ideas.  If you think of something else, please don’t hesitate to let me know.

LauraRey

@BrianZ  This one doesn’t have an outside shower, but good thought.

ScottG

Okay...  It sounds to me like the pump activates as it should, and is able to build pressure in a closed system but not maintain it when a tap is opened.

I know you tested the pump in isolation, but are you sure it was operating at capacity? if the flow was under spec that could cause the problem you've documented 

My only other guesses (and weak ones at that) are an air leak in the intake line between the tank and the pump, or a leak in the pump's integrated check valve. Under the right conditions either of these could cause a reduction in pump flow or pressure.

LauraRey

@ScottG I didn't take the time to measure the amount of water in the bucket or how long it took for the pump to empty it, but it was fast.  We use pumps a lot at our cottage and nothing about this one struck me as not working at capacity.  However, after I finish the sanitizing cycle, I'll test it again to verify that it is pulling at capacity.

Checking for air leaks in the intake line will be a challenge given the location of all the connections.  Holding off on that until I don't have another option.   Although, if there was one, I would expect to hear the pump cycle on ever so often for "no" reason.

Subism

I am happy it was not a leak and hope you find the issue and it is an easy fix. I am sure you are quite frustrated by now>

ScottG

The pump might not cycle on and off if the check valve on the intake (upstream) side of the pump was operating properly, as leakage backward through the pump would be prevented.

I would expect the pump to cycle periodically if you had a leak on the distribution (downstream) side, as pressure would build but not be maintained as it dissipated through the leak. Your symptoms don't seem to fit that diagnosis.

I do agree that checking the intake for air leaks will be challenging. Hopefully an easier resolution will surface before then. Good luck with the mystery and keep us posted!

LauraRey

@ScottG That's a very good point.  It could be on the intake side and it wouldn't trigger the pump.  Sigh.  I wish it weren't.  I'm going to have to think about how to test that.  Suggestions will get you a cup off coffee if we're ever at the same campground.

Subism

@ScottG, good point on the pump cycling with a leak on the distribution side. That's why I like this forum, everyone contributes from their experiences and expertise and we can then put all of the pieces of the puzzle together!

@LauraRey , if you allow the pump to build pressure and leave all faucets closed, then wait to see how long, or often it restarts to maintain pressure you might get some indication on whether there is an intake side leak. I don't have enough time running off the FW tank to know how long it should hold pressure, or how often it should cycle; but with all the people on here who boondock regularly, maybe they can help. Edit: Scratch that, I think that would only work from the pump check valve and in to the faucets.

Another option: I believe you mentioned you isolated the pump by drawing from a bucket. Did you, or could you do this while the distribution side is still plumbed and see if you have the same decreasing water pressure issue at the faucet? That would seem to help you isolate to the FW tank and intake hose.

ColoradoJon

It appears to me that the problem is on the inlet side of the water pump.  This means there are only a few causes:

Blocked vent line as suggested by @ScottG
Blocked water pickup/inlet line as suggested by @Dalehelman
Weak water pump as suggested by @ScottG

I do not suspect a leak as you would have difficulty priming the pump.

Were you able to scope the entire length of the pickup line?  Can you use an air compressor set to 30PSI and blow some air through it?  Do the same with the fresh water tank vent, but lower the pressure if you do.

I suppose that there could be some sludge built up on the bottom of the tank that is interfering with water pickup, but have no idea how you would test or even clean it up!

LauraRey

@ColoradoJon I wasn't able to scope the entire pickup line.  I've sanitized the tank and drained it a couple of times.  I'm not seeing anything in the discharge that would make me believe that it is blocked.  So, just to be rule it out entirely, I'm going to swap out the pump.  It should get here tomorrow and I'll install it.  After that, if it still isn't working, then I'll have to take it jack it up, remove the panel on the bottom and start seeing what I can find.  Thanks for your input.

ColoradoJon

Yikes... what an interesting and frustrating problem.  I suppose that the problem could still be a partial line blockage on the outlet side of the pump.  Do you get the same symptom with both the shower and the sink faucets?  What about through the hot water tap?

LauraRey

@ColoradoJon It happens in both the kitchen faucet and shower.  Haven’t added the Alde into the equation to keep it simpler.

ColoradoJon

@LauraRey - well, I don't have much else to add, sorry.  Unless you want to try running water through the Alde to see if it affects the entire system or just the cold water, but I think the Alde hot water tank has a bladder and creates it's own pressure.

Others have already covered the items that I would question.  If I was near you I'd be interested to take a look!

LauraRey

Update: I installed a new water pump.  It is much quieter than the old one, but the problem remains.  I’m going to call Nucamp in the morning and schedule a time to bring it in.  Since I’ve been wanting to get the back seat split, i can make a trip of it.

LauraRey

I'll be taking the trailer down to nuCamp soon. I must say that Austin has been so very easy to work with on setting up the appointment.  He thinks it is a crimp that isn't quite tight enough.  I admit, I'm quite curious after all we've done to try to solve the problem.  The suspense is intense.

Haloo

There really needs to be some sort of raffle or contest associated with this.

LauraRey

@Haloo
I totally agree.   

LauraRey

And the winner is @Dalehelman!  It took them a little while and they had to take the bottom off the trailer.  They found the problem:  there was a ball of plastic stuck in the stack pipe.  It was only slightly smaller than the diameter of the pipe.  So, Dale was right, it was an obstruction. I would never have found it.  Austin was wonderful to deal with and I finally got to meet Elsie!  All around...a great company.