Newbie Water Issue

SkiCO

I have followed the previous threads trying to get the pump to prime.  Not drawing any water.  Things seems to work fine on city connection but after checking pump lines and filter no water seems to be drawing from the tank.  Any suggestions?

phulishcat

Had this problem a few weeks ago, the dealer showed me how to fix it. Grab a rag and head to the nearest air pump at a gas station. Turn the pump on, then using the rag around the air hole to make a not quite air tight seal pump air into the gravity fill opening. This will force water and any air bubbles stopping the pump from drawing through the line and re prime the pump. My dealer also suggested never running the fresh tank totally dry with the pump. If you want to drain the tank there's a drain valve under the camper.

SkiCO

Thanks so much!!!  I will try this ASAP,  I worked all night tracing the hoses and checking the pump to trying to get it to work...  Hopefully this will solve the problem!!

rfuss928

Using the "blow" side of a shop vac should be enough pressure without risking over-pressurization. 

JohnDanielsCPA

I keep seeing these kinds of posts and am at a loss.  I can't speak for the T@B, specifically, but if the pump is not priming, there are only a few things that can be causing this.  There are valves open, somewhere, that is allowing air into the system; (e.g. The low point drains are open, the inside or outside shower valves are open, etc.)  So first thing I would do is make sure ALL valves in the water system are closed prior to turning on the pump.  Another possibility is there is not enough water in the fresh water tank, so it is "sucking air."  The next possibility would be there is a leak in the plumbing, somewhere, (which is a low possibility unless the system wasn't properly winterized), or the tubing is loose around the water pump or the filter on the pump is loose.  If all that is good, I can only conclude the pump is not an appropriate size for the system.  Of all the RVs I have owned, one of the above turned out to be the cause.  This is the first time I have ever heard of forcing air into the lines to get the pump primed.

SkiCO

We have water!!!  Thanks so much for the great advice!!

Ron

I have the same problem.  Every time I run the tank dry it will not prime.  Pump is not a good enough vacumn air pump to lift a column of water the two feet or so that is required to prime itself.  No problem if in a campground, but not much fun out boondocking.  
Solutions as I see them are a different pump, lower the pump to reduce the lift requirement, or add a priming pump.  Sureflo and flojet both have this problem.  They are designed to push water not pull air.

TabberJohn

Ron said:

Solutions as I see them are a different pump, lower the pump to reduce the lift requirement, or add a priming pump.

Are there any model T@Bs with the pump mounted low to compare performance?

Michigan_Mike

I replaced the original pump that I had on my T@B trailer with a Shurflo pump that had an additional 5 psi of force.  And my experience has been that when the FW tank gets down to around 25-27% water volume the pump begins to struggle and obviously starts sputtering and sucking air into the water lines.  This is what makes the SeeLevel ll tank monitoring system so valuable because you know exactly how much water is in the freshwater tank.

If you fill up the tank, flip the pump switch on and let the  pump begin to work and at the same time open up the faucets on the sink.  This will allow any air in the system to escape and allow the pump to pull water up out of the freshwater tank.   If the pump is still struggling at this point turn off the faucets and flush the toilet a few times quickly if your trailer is equipped with one. 

  I had to chuckle a bit when I heard the advice from the dealer, but maybe that little task is intended to free up any debris that may potentially be down in the freshwater tank as a result of the trailer being built?  I don't think I agree with that advice or strategy as it would be difficult to create enough pressure through the freshwater fill point.

I did find a little debris inside the original pump filter but personally I was not happy with the factory installed pump and replacing it was the best thing that I had done and the new Shurflo unit works like a champ!

Ron

I get bits of plastic when I suck on the inlet hose to the pump.  It seems that I should be able to suck water up that hose.  I get air for awhile and then no more air and never any water.  Line holds a vacumn at that point.
Is the tank outlet on the top or bottom side?  Can I get any access to clean the tank.  Perhaps something is blocking the pickup tube.  Once it has prime it works well though.  Plenty of flow and pressure and pump starts and stops as it should.  The only way I've ever got the pump to pickup it's prime is by opening faucets and pressurizing the tank with a fill hose.  Not a good long term solution.
For the price the water system should work.  Read other RV forums and the problem seems to fairly common with these pumps.  The big motorhomes have the pump close to tank level and the problem seems to be just purging the air out.  If an RV is advertised to have a certain size fresh water tank, that is what you should have available to you.  Not have to save 25-30% just to keep the pump operational.
Michigan-Mike, what pump number did you get as a replacement?
Also the tank drain pepcock flows freely.  Does the water for it come out of the same hole in the tank?

Ron

My sailboat that I cruised and lived aboard for many years would have a similiar problem.  Both tanks had a low point valve on one side that the water was pulled from.  They also had two access ports on top that allowed you to clean the tanks a couple times a year.  "They do get dirty".  
The pump was just about tank top level and would require just a little help to pick up the prime if run dry.  I would just suck on the galley faucet a bit and the pump would pick up.  It still had the original Surflo pump, 1990, when I sold it 20 years later. Good pumps, but they do not seem to self prime the way the manufacture claims that they do.

ScottG

One thing I have noticed is that the fresh water tank vent (the clear plastic tubing that runs from the top of the tank to the small hole above the filler port) is susceptible to kinking and pinching as a result of less than careful routing. I suspect this contributes to the problems people have filling the tank (where air must be forced out), but it could also contribute to a tank vacuum that may complicate priming the pump.

The pressurizing trick does make a bit of sense, provided you also cover the tank vent hole (and there are no other vents in the tank). However, even if it did work as described, that's way more trouble than I'm willing to go through for something that should be more user friendly. I agree with JohnDanielsCPA--if the system isn't working than something is leaking or poorly engineered.

SkiCO

The reverse shop vac with a rag at the filler port did the trick for me.   Unfortunately, our 18v hand small shop vac just got added to the must take list for the near term as we will almost always be boondocking and don't want to get stuck with a vacuum pressure problem.  Once it primed things were great until 18% on the FW tank.  I had to again use the vac to repressure after filling to 94%.

JohnDanielsCPA

Tonight was the first time I had water in my system.  The steps I took were to start by sanitizing the tank; (supposed to be 1/4 cup bleach to 15 gallons of water, but for such a small tank, I think that's a bit too much).  Next time, I will reduce the amount of bleach.  To pressurize the system, I started with the thing closest to the pump; the toilet.  It took about a minute, but the water came.  Then I ran the kitchen faucet, which came quicker.  Then the shower.  At this point, I am only running cold water.  Everything worked fine.  My tank was at 100% (per the SeaLevel guage) prior to running the pump for the first time.  My first thought is I think the pump may be a bit on the light side.  I will work with it through the summer, but I may be doing what Mike did, above, and swapping out the pump.