water pump sputter - sucking air

[cjmitch]

I am forever having issues with what I thought was my water pump. It will not get the air out of the system. Last weekend it wouldn't shut off and it sputters. When I returned home I did a test to prove that the water pump was good. I hooked up directly to the pump with a hose in a pail of clean water. Turned on the pump. It primed, filled the water heater and shut-off. I went inside and opened faucets. The air cleared the lines and everything was good.
Question - does anyone know the best way to find the air leak on the incoming side of the pump. It has to be a fitting or something on the back side of the water management system. I have tightened all of the connections I can get at and changed 3 sealing washer / rings.
Any help would be much appreciated as we are going out this weekend with the grandchildren. I am going to need water...........

 

[Screwby]

Did you ensure all the valves used to winterize were in the correct position and not leaking. Most water pumps have a valve that controls a tube used to suck antifreeze into the system and if it’s not shut all the way or faulty it could suck air into the system. You can visually make sure it is shut and hold your finger over the end of the antifreeze tube to see if there’s any suction while someone kicks on the pump. Also just had another member find out his little clear housing that holds a small filter on the bottom of his pump was cracked allowing air to be sucked into the pump.

 

[cjmitch]

Thanks for the info. I have a whole water management console so I am not sure I can isolate just the winterize portion of it.. I removed the clear strainer last year and that seemed to fix the problem (after I had already bought and installed a new pump).

 

[Screwby]

Ahhhh so you have an RV with the control panel with all the valves you turn to winterize, city water, and bypass. Probably all color coded with diagrams for which way to turn the valves for different functions?

My advise was for the smaller RVs that usually have the pump under the sink or a cabinet and the valves are located next to the pump and next to the water heater. Simpler and out in the open to see and not hidden behind a panel you can’t access. Hopefully someone chimes in that has better advice

 

[Screwby]

Actually I remember seeing a post about the filter screen where you attach the city water hose has a check valve behind it and the screen can become crooked or flipped around backwards and press the check valve slightly causing a pressure leak. Worth a look?

 

[cjmitch]

I'll check that thanks. I thought about putting a plug in the city water connection to test for that.

 

[norty1]

Try exercising the valves on your utility panel to make sure one is not set exactly.

 

[Jagiven]

Actually I remember seeing a post about the filter screen where you attach the city water hose has a check valve behind it and the screen can become crooked or flipped around backwards and press the check valve slightly causing a pressure leak. Worth a look?

First thing I thought of was that little filter screen. It needs to be facing outwards towards the street. Inwards, it pushes on the check valve, so the pump can lift antifreeze from a jug.

 

[cjmitch]

Thought of that and checked it, but thank you for bringing this up. I thnk I'll screw a plug in the city water hook up to take the check valve out of the equation. Worth a try anyway.

 

[RetiredOne]

Question - does anyone know the best way to find the air leak on the incoming side of the pump. It has to be a fitting or something on the back side of the water management system. .

Two things I would check, look at the filter screen and jar attached to the pump to make sure that plastic jar isn't cracked (possibly from freezing). That might be the source of sucking air.

Also, make sure you bleed off ALL air in the system, by opening the low point drains and any showers (inside and out), and any other water valves, icemakers, washers or water fittings. Sometimes trapped air can make a faucet sputter and make a pump act erratic.

 

[Jagiven]

Next thing I would check is the at the inlet of the water pump. There is a screen filter bowl. Verify that it is in good shape. The bowl on mine was all micro fractured the first year I had our TT. It sucked a lot of air, and the pump would cycle often

 

[RetiredOne]

I guess I'll ask a real dumb question. Is the OP sure they have plenty of water in the water tank so it's not sucking air from a empty tank??

 

[cjmitch]

RetiredOne
I did away with the strainer and bowl last summer as I believe it was cracked and contributing to my problems.

I hooked up a hose direct to the pump last night and pulled water out of buckets. The pump worked flawlessly and purged all of the air out of the system. I only have the problem when my incoming supply line is coming from the tank via the water management panel.
Thanks for you thoughts on this frustrating subject.

 

[cjmitch]

Last night I added 30 gallons of fresh water to the tank. I screwed a plug in the city water connection to rule out the check valve. The pump won't pump up to pressure and is still pulling in air from somewhere. I got some soapy water in a spray bottle and sprayed the fittings with the pump running to see if it would suck in any of the bubbles. That was a bust as you could see nothing. I think I am convinced it is the black valve on my water panel. I had the same problem last fall when I winterized with suction and air. Previous camping trips this year have been full hook up so I haven't needed the pump. The black valve is the winterizing valve and is the only thing i see in common with running the pump from the tank.
Thoughts anyone??

 

[Screwby]

Unfortunately it sounds like you may have to access the rear of your control panel to have a look. It’s possible you’ve got a faulty valve or a loose/cracked fitting on the backside that you just can’t see. I had a bypass valve go bad on my 5th wheel that wouldn’t let me winterize correctly. I couldn’t visually see anything wrong so something internal wasn’t working properly. Very frustrating.

Have you plugged the suction port for the antifreeze tube or stuck your finger over it to make sure it’s not sucking air? Possible you have a problem with the pickup tube going down into the fresh tank but that’s going to hard to diagnose.

 

[cjmitch]

Friday 6-5-20 I purchased a new ball valve for the black (winterize) valve on my Nautilus P3 water management panel. It was common to problems winterizing last year and also to sucking air in the water from the tank. It seemed to work. It took some time but it did pump up and shut off. Soooo I went camping Friday with wifey and grandkids.
Got to the site, set up and turned on the pump. It was ok until the first toilet flush. Then the pump just ran and ran. I shut it off. Turned it on later and it pumped up and held. We played the same game all weekend.
There is a bit of a leak behind the toilet so I have parts to rebuild that. I will take it apart as soon as I have time. It still seems to be on the suction side of the pump to me though.

 

[DaSkipper]

This may not go directly to what's causing your pump's failure to prime, but on my 2016 Redhawk 23 X 2, I've learned that when I switch from city to "normal" (the pump) that the pump usually has to re-prime, which can take up to 10 minutes. After that it works okay. My theory is that the line from the Utility Panel to the tank drains out to the tank while the city supply is being used. Also, the pump documentation says the tank should be within six feet of the pump suction. Because the line from the tank is routed through the Utility Panel valving before going to the pump the run is at least ten feet, which does not account for the lift from the tank. If your rig also has a longer run from the tank to the pump it could allow even the tiniest air leak to aggravate the priming. And as you mentioned, not all the piping fittings are accessible to examine.

 

[Dave A]

It was a Valve!!

Unfortunately it sounds like you may have to access the rear of your control panel to have a look. It’s possible you’ve got a faulty valve or a loose/cracked fitting on the backside that you just can’t see. I had a bypass valve go bad on my 5th wheel that wouldn’t let me winterize correctly. I couldn’t visually see anything wrong so something internal wasn’t working properly. Very frustrating.

Have you plugged the suction port for the antifreeze tube or stuck your finger over it to make sure it’s not sucking air? Possible you have a problem with the pickup tube going down into the fresh tank but that’s going to hard to diagnose.

We had one of those valves leaking air in the control panel and the dealer replaced the whole control panel under warranty. Bet that was a chore. Ours wouldn't suck water from the fresh water tank or from a bucket when when used the winterize setting.

 

[Duke Orr]

CJ, I chased the same issue with my nautilus P3 system a few years ago. After many weeks replacing the rubber o-rings, putting a plug in the intake etc. I found two 90 degree fittings with hairline cracks. They looked like manufacturing lines at first but when I spread the fitting by inserting needle nose pliers inside and opening the pliers, you could then see they were indeed cracks, I suspect maybe from not being winterized properly by the previous owner. I couldn’t reach the back side of the console so I had to remove it. It was a royal pain. If you search my user name you should find a string from 2017 or 2018 on this topic