Pump not pressurizing - dry camp valves stuck?

ybakos

I have a 2022 CS-S and during the tenth-ish setup of camp with the Nautilus in "dry camp" mode I noticed the pump was not pressurizing. The freshwater tank was full. No flow or initial sound of water flowing, just the pump running. Let it run for a couple minutes, then turned it off. Checked the Nautilus panel valve settings - dry camp. Ran the pump again for a minute, no flow / pressure, turned it off. Tried rotating both the green and blue levers, and then put them back into "dry camp" position. Ran the pump again for a minute, no flow / pressure.

Decided to let it run one more time, and suddenly there was the usual water flow sound and pressure built quickly.

Have others experienced this? Is it due to, for some reason, having a completely full freshwater tank?

I'll report back if it happens again.

pthomas745

A "couple of minutes" may not be enough for the pump to bring the trailer to pressure. The main things to check are: the drains.  If any of the drains are open (have you checked the Famous Yellow Flapper Valve?), or any faucets are open, even the smallest bit...then the pump is simply sucking air and will never come up to pressure.  So, have a look at every faucet, shower handle, low point drain.  Give the pump a few minutes with all the faucets closed.

ybakos

The previous ten-ish times of turning on the water pump when setting up camp resulted in the system pressurizing very quickly (about a minute) accompanied by the immediate flow / sound of water.

No taps open, no drains open, yellow flapper closed.

stp2136

When the pump loses prime (with seems to happen any time you move the trailer) it will not reprime if there is ANY residual pressure in the lines because it is not very efficient at pumping air.  With the Nautilus valves in the correct position for dry camping you need to open a faucet to bleed off pressure and then let it run with the pump turned on.  It will reprime and build pressure within 30 seconds or so.  

ybakos

@stp2136 I'll try that next time I dry camp. Thanks for the suggestion.

ybakos

Dry camping now and the same problem. I have checked each thing recommended and tried all suggestions. 😵‍💫😵‍💫

ybakos

I have let the pump run for about five minutes and no pressure. I do not see or hear any flow of water by the pump, and I should. 😫😫

ybakos

Opened and closed all drains. Ensured yellow flapper is in the horizontal (not vertical) position. Bled off a little fresh water drain and closed it. Tried opening faucets and running for 30 seconds and closed. Ran for additional minutes. No flow by the pump.

Sharon_is_SAM

@ybakos - you need to get a pan of water, disconnect the pump intake hose and place the end in the pan.  If the pump does not draw water, you have a bad pump.  If it draws water, reconnect and see if you can now get it to pressurize.

GregChris

did you check the pump filter?

pthomas745

One more thing to add to check for the "integrity" of the plumbing system is the array of valves/pipes/connectors on the back side of the Nautilus panel.  There have been enough reports of small leaks and loose connectors in that area that they should be added to the list. 

The pumps are very reliable little beasts, but when these things happen it can make no sense. There are adjustments to the pumps that can be made.  Two videos in the thread below that explain this, and the rest of the thread will be useful, too.

https://tab-rv.vanillacommunity.com/discussion/5588/pump-problems/p2

ybakos

I checked the filter, unscrewed, very clean, screwed back on making sure it is threaded correctly. 

Checked all the connectors and hoses on the back of the panel but will check again.

ybakos

Ran on city water and let it every faucet run, hot and cold. Filled tank. Put on dry camp. Turned on pump. Running, doesn’t stop. Opened tap with pump still running. Loses flow, pump does not stop.

I do not see water flowing through the filter into the pump.

Bad pump?

Sharon_is_SAM

@ybakos - you need to get a pan of water, disconnect the pump intake hose and place the end in the pan.  If the pump does not draw water, you have a bad pump.  If it draws water, reconnect and see if you can now get it to pressurize.

ybakos

Thanks @Sharon_is_SAM and everyone, and apologies I have been slow to troubleshoot. Busy days!

I purchased a 1/2" FIP / compression hose from the hardware store. Removed the water filter from the pump input and attached the hose. Stuck the other end of the hose in a cup of water. It did not draw any water. (Faucets open, faucets closed, same behavior.) When I pull the tip of the hose just out of the water, I hear a very quite gurgle, but nothing significant. I put the end of the hose against my palm and could feel no suction against my skin. Upon removing the hose, I find that it does not seem to contain any water, so I am fairly certain the pump is not sucking.

I'm including images, a video and the details of what I did here to help others, and to be sure I did this right.



1-minute Video: https://imgur.com/a/FNubQF0 (I am not sure why imgur is saying one must be over 18, I promise it's not a Rickroll or anything other than me running the pump with the tube in the cup of water.)

I am going to order a new pump now. This pump has been used on only ten trips and never abused. It's on a 2022 Tab 320 CS-S. I am surprised by the poor reliability of the pump.

Sharon_is_SAM

The only other thing to try is to raise the inlet hose and pour water into the hose to see if you can prime it that way.

GregChris

In another thread, someone mentioned the filter cap being loose or cracked, small cracks barely visible. 

Maxcamp8

We too have chronic loss of pump prime issue, after each trailer move.  Fine when stationary.  Things that have helped quite a bit but not completely:
1.  Replace clear plastic screw-on top to pump strainer.  This helped a LOT.  Maybe $6 on amazon.
2. hand tighten various screwthread pvc fittings.  
3. 15psi compressed air leak testing of line fittings.  I redid two Pex fittings that were not tight, albeit downstream of pump and therefore unlikely to affect priming.  There are pex fittings below coroplast scrim under rear of trailer, that lead from tank outlet to pump inlet.  Reworked these today while rebuilding the tank drain to a larger diameter to be effective.  Will see if these helps.

RalphD

I am experiencing this same issue and studying thread for solution. I will report back. I purchased this 2023 tab 320 last week. It shouldn't be this difficult

ybakos

After verifying that the pump would not suck anything, I contacted Pentair/Shurflo and they sent me a replacement pump, no questions asked.

I just replaced the pump, then:

• used city water to fill the lines while running the taps (cold and hot water)
• filled the freshwater tank
• turned on the pump
• opened the kitchen tap

... and... pump ran but would not build pressure.

I checked and saw no flow through the filter / pump intake. But then I pressed open the Alde relief valve and heard a loud, long squirting sound and saw that the water seemed to now be flowing into the pump.

Yay!

To recap: my pump is what failed, and a replacement seems to have resolved my problem.

Thanks everyone for the troubleshooting suggestions.