Ongoing water pump issues

[rgnprof]

Ongoing issues here - had another thread but it died and my issues have developed...


Problem: we were camping in below freezing temps over the holidays and the pump wouldn't pressurize, then it wouldn't run at all, and then when I got it running (after some things thawed - I THINK!), it wouldn't shut off.



I replaced my Shurflo 4008 with another one and problems persisted. Since we have gotten home, I think I have made some diagnostic process. Currently, faucets sputter, low water pressure and pump will not shut off when faucets are closed (Again - new pump still installed). I see no dripping water anywhere and I've looked everywhere - BUT when I turn off the pump it does shut off AND I start to see water dripping from several connections in my bay where the pump is and water filter is located. I'm guessing that I'm sucking air when the pump is running and think I have some loose PEX clamps - sound reasonable?



Question: If the fittings (or the PEX pipe) can spin at a PEX clamped connection does that suggest a leaky connection?


So, I am in the process of replacing all of this plumbing (see Pic).


The other issue I have is I am getting hot water running through my cold pipes. In the attached pic, the water flowing out of the PEX is HOT and it runs for minutes after I have shut the pump off and with no city water connected either! Matter of fact, I routinely have running water with no pump running and no city water connected...and it's hot water.



You can see the water pump hose (the bottom curved vinyl hose) and the disconnected hose is the hose that connects to my city water valve (which I also just replaced this weekend).


I'm not sure what else to look for...

[Paul_D]

This is a stretch. If your outdoor(or indoor) shower faucet has both valves open and the spray wand turned off. And there is air in the hot water heater tank, the pump would pressurize the heater tank, the check valve will prevent the water going out the cold side, but the hot water side has no check valve. So the hot water in the heater is pushed out through the hot water pipe, crosses over in the shower faucet and comes out of the cold faucets.

[Vato]

Worth a look

https://www.youtube.com/watch?v=DsPCPr8ptmk#ddg-play

[Persistent]

You guessed correctly. Your RV water system froze.

There are likely many points of damage. Many people stopped responding to your old post because helping you without seeing and touching the plumbing is an impossible task.

So, the sputtering water flow is due to the pump sucking air through fracture points. The crack may be in the pump itself or in any fitting, filter housing or pipe between the pump and the fresh water tank.

You found one loose PEC fitting. There are probably many hidden inside the walls.

Various check valves that normally keep hot an cold water apart are probably broke. Faucet valves may be broken inside. Air in water heater may be keeping the system pressurized when pump is "OFF". Maybe you have a pressure tank with broken check valve. Lots of possibilities.

Water pump continuing to run may mean air in the pump or hidden leaks that continue to draw water, or both.

Even if you find the crack, that will probably not end your problems. There are probably many points of failure. Small leaks may show up months or years from now as structural failure due to water damage.

Many people would despair at the cost of time and money to totally disassemble your plumbing system and rebuild it.

Sorry to be be bearer of bad news.

[Mike Finnerty]

My guess is the pump is running because it can't build pressure to the cut-off psi. Usually due to a leak somewhere in the system. Check that all shower faucets are turned off. Your shower wands could be leaking at the turn off button. The sucking air thinking wouldn't apply if you have water in the tank and your winterize valve is closed.

[rgnprof]

Well I am quite the pessimist, but maybe not as persistent at it as 'Persistent' As stated in my previous post I kept the water line areas warm - well above freezing although it's possible that the front of the freshwater tank bay area got cold enough to possibly freeze - which would have affected the line running from the freshwater tank to the pump...



While it could be that bad I don't really see any signs of that. If I bypass the pump piping and run directly from city water, everything is fine. No leaking anywhere, good water pressure etc.


Today I changed out the hoses in the bay (in the pic above) - new PEX connections, new elbows, new tee (all brass) and system runs much better. I jostled and moved these some during some of this testing and poking around process, which might have affected a few connections. Water pressure is good, no more sputtering and no dripping - with pump on and running and off.


BUT - pump will still not turn off after shutting off faucets and I'm still seeing pressure and running water after shutting down the pump. I'm thinking these issues are connected???


In the attached pic I have a brass part circled in red (Is that a check valve?) and the bypass valve is in purple...FYI - the hot water tank is just to the right with the outlet connected to the tank via a 90 deg connection just to the right of the red circle.The hose from the tank runs up along the tank and bends back and connects to that brass valve in the red circle.


Also, I checked all faucets including the outside faucet (which is new and never been used much at all).

[LoneTux]

Originally Posted by rgnprof

Problem: we were camping in below freezing temps over the holidays and the pump wouldn't pressurize,

Well you have actually stated the solution in this sentence. The simplest solution is not to camp in freezing temps if the issue with the freezing which froze and cracked some water pipe is not solved.



I have been full time living for 5 years now, I get freezing temps up to -20°C (-4 °F) each year and I already have another solution to these problems tho.


Solution is to add more insulation.


Especially I recommend crafting a flat bag from 2 pieces of any flexible relatively strong material and add some kind of rock wool into the bag, then put the bag into the door of all water and sewage compartments.



When you make the bag, the X/Y dimensions of the bag should be about 10-20% bigger than the door you will be putting the bag into, it should be a tight fit.

[LoneTux]

Second solution is more complicated:


To create a water loop (with extra pump) that will continously run on timer or all the time and cycle water through your whole RV. The loop should envelop your whole vehicle, meaning, it should run from the front to the back. This requires some pipe work and electronics.



For example, you could craft a simple circuit or buy one (something like this is can be done using off-the-shelf 12V electronics with no programming necessary) that runs the such a "loop pump" 5 minutes every 20 minutes automatically once temperature drops below 32 F.


It's not as simple to do as my first solution, but will definitely solve the problem forever.

[SafariBen]

Pex can be rotated on the fitting, that does not indicate a loose crimp. I've never noticed crimp ring loose enough to rotate on the pex, but don't use the SS style.


None of this is complicated, there is a pressure switch, usually built into RV pumps. If you cap the outlet and run the pump with water, it should shut off almost immediately and come back on when you release the pressure. That proves the pump and pressure switch are working. If the pump will NOT shut off when hooked to the plumbing, then water is obviously running somewhere.



The hot water running from cold faucets after the pump has been shut off has been explained already. The drips from the water system are not explainable by me, unless they're o ring fittings that need pressure to seal?


There is no easy answer besides what's been suggested, either take the time to figure it out, or call a handyman, or ask more specific questions to figure it out.

[rgnprof]

If you cap the outlet and run the pump with water, it should shut off almost immediately and come back on when you release the pressure.

Yes - I will do this next. Already tried but I didn't have a cap to screw on outlet - tried to put together a hose connection with a plug etc - but it dripped some...

The hot water running from cold faucets after the pump has been shut off has been explained already.

I must be slow, but I'm not sure I've seen an explanation - seen some ideas suggested. I posted a specific question - with a picture - is that a check valve in the hot water line? But I'm not seeing a check valve in my cold water line anywhere...which was a possible idea proposed earlier in this thread by Paul_D...

[Persistent]

The circled brass device is a check valve. It is part of the winterization bypass system. If it is still working, it prevents antifreeze from flowing into the heater tank through the output fitting.

There should be another check valve on the heater tank input to prevent hot water from flowing back into the cold water side.

[rgnprof]

Ok - thanks! I do not see another check valve on the cold water inlet line anywhere...

The circled brass device is a check valve.

Do you mean the red or purple circle? The valve circled in purple is the water bypass valve - see attached pic.


Also - I plugged the water pump outlet this afternoon and the pump shut off immediately - so the pump is operating properly.

[rgnprof]

So this is the system on my Fleetwood from Swan Industries - this comes with the 1/2" bypass valve (purple circle AND the 1/2" brass check valve (red circle). This is the only place I can figure out where the problem might be - other than the hot water tank itself??



https://swanindustries.com/collectio...ter-bypass-kit

[Paul_D]

Here's an idea, turn the heater bypass valve to bypass and see if the hot water still comes out of the cold faucets, after the you shut off the pump. Actually see if any water comes out of the faucets.

The bypass will take the heater out of the loop. If it's air trapped in the heater tank acting like an accumulator, moving the bypass valve, will stop both the hot water reverse flow and the continuing water flow after pump shut off.

If the pump shuts off, it will tell you the issue is in the bypassed water heater plumbing.