Water pump not priming.

Ken35216 · 11-15-2020, 02:36 PM

Hi,

It works some of the time and does not work some of the time. I have 3 on/off switches. Down below where the water pump is, in the head, and on the control panel wall.

It usually stops working when I attach city water or fill the tanks.

I can't figure it out.

Any ideas?

Thanks!
Ken

P.S. are you supposed to run the pump when you're attached to city water? I have a couple of times and as it gives it a little more water pressure in the shower.

Morich · 11-15-2020, 02:57 PM

Sounds like a problem with not getting the valves for filling tank versus normal put the right way? Better not to run the pump when on city water, I feel.
But I do know that leaving the valve on the wrong way like after filling the tank, leaving it on tank fill will cut water flow and I'm not sure what it may make the pump not do!
I would want to divide the question into electrical versus a pump prime question. You should expect to hear the pump run when any switch is thrown but priming is a different problem as a valve left open can make the pump try to move air and just pull more in through a valve left the wrong way.
Maybe check this valve is set to normal except when filling tank? One could say a drain valve might be left open but those usually give us wet feet and we notice!

**Eagle5** · 11-15-2020, 04:36 PM

After winterizing on the Eagle5, I need to have my fresh water tank completely full, so that the pump will prime.

Ken35216 · 11-15-2020, 06:21 PM

I can here the pump running it's just not priming. It does about 1/2 the time.

I just get air through the sinks/shower.

Really frustrating.

Morich · 11-15-2020, 06:31 PM

That does really sound like a valve open as it does need a place to draw the air. This is assuming there is enough water in the tank to cover the end of the pipe going to the pump? The pumps are designed to pull suction for a pretty good amount of level difference but only if there is not a away for them to get air. something like leaving the cap off the suction tube used for winterize anti-freeze can drive us silly!

Ken35216 · 11-15-2020, 06:32 PM

I have 1/2 tank of water.

Winterbagoal · 11-15-2020, 06:34 PM

Have to ask, have you checked the pump's filter screen holder (usually on the intake side hose of the pump) to make sure it's tight? I'd also trace and check all the other hose connections wherever they are, for tightness. Make sure you aren't leaking air into the system. I've found loose connections that just needed an extra twist on the connecting nut to seal the gaps where the hoses are connected to each other and the appliances, like the water heater, the water filter, various valves, and so on. Not always an easy job, but it will eliminate a leaky/loose connection as part of the problem.

Morich · 11-15-2020, 07:15 PM

Looking closer, I see the pump has a very short distance to actually suck water from the tank but it does wind a orund a bit to make it hard to spot how the water flows, so I have done some marking to show the route.
If you look at the picture I posted above and spot the valve I mentioned, then think of looking down on the top of that panel and seeing the fresh water tank and pump.
When the pump runs, it makes a suction on the left side coming through the intake filter(shown in red) coming from the area of the valve and suction tube. If this valve is turned the wrong way, air can enter through the suction hose there and not draw water.
But if there is no leak there in some way, the suction the pump makes will draw water from the tank out line--- if there is no air leak!
Think of it as you using a straw and air gets in at some point so that you don't get a drink?
There should be one short flexible tube laying loose and that is the suction tube, so it can be tested by taking the cap off and then turning the valve both ways to test if the suction tube sucks on your finder when the pump is running. If it sucks on your finger, the valve should be turned the other way so that it sucks from the tank direction.
First guess would be to find a leak in that little section of tubing that runs in the circle, but there are times when debis gets left in things like the tank and it may have stopped up the pump filter or the intake line, so check for that. The filter is just a simple screw on type thing so remove and check it if not finding anything else?

kcscriv · 11-22-2020, 05:52 PM

Me also Eagle 5, had to this last year, don't know why, and it had to be completely full.

kcscriv · 11-22-2020, 05:55 PM

Eagle 5 same here, and it has to be completely full

PeteK · 11-22-2020, 07:10 PM

I have had a similar problem and the pump runs without turning off. The cause of the problem, I believe, is the pump becomes air bound not allowing water to be suctioned into the pump. Some times it takes a few seconds, minutes or longer for the air to pass through the system. What causes it I am not sure. It could be an accumulation of air from the water supply.
Peter

IOS 3 · 11-22-2020, 07:35 PM

Hi Ken - No, you should not run the pump when connected to city water. The pump has a check valve built in to it so that when you are connected to city water you don't "reverse fill" your fresh water tank. So, when you run the pump while connected to city water you are triggering a fight between the pump and the city water. Whoever generates the most pressure wins....

Because the pump is functioning, and pushing air through the system when not on city water, it sounds like you have a leak somewhere in the system that is letting air in... which is preventing the pump from pulling a vacuum. The first two things I would check thoroughly are the fill valve in the wet bay, to make sure it is firmly in the "normal" position. Second, as others have stated, is to be sure the filter at the pump is not compromised in any way (clogged, cracked, etc...).

Did you buy the rig new, or is it possible the prior owner did something to the plumbing that is causing this problem now...?

I have your exact rig, so happy to discuss in more detail on a PM as appropriate.

Thanks!

Upinsmoke · 11-23-2020, 03:10 AM

I've had this problem in the past. In the short term I solved it by loosening the discharge line from the pump. Initially air came out but was quickly followed by water. I tightened it back up and we were good to go.

This Fall I removed the pump and put all of the rebuild kits in it that I could find. It was inexpensive (IMO) and easy. Whether it solved the problem remains to be seen but it did work like a champ when using it to suck up anti-freeze to winterize it.

Good luck.

Ken35216 · 11-25-2020, 04:13 PM

Well, I'm not so smart.

Took the RV into the shop today for a couple issues and he figured out the water problem. In hindsight it makes sense as it worked sometimes and didn't work while the RV was leaning on the starboard (passenger) side. The shop guy said that 27N has a "pancake water tank" which means it's long but only 7 inches tall. If you lean more than a couple degrees to the right it will not suck water from the tank.

The pump pumps water when it's level.

One more thing figured out

Ken35216 · 11-25-2020, 04:18 PM

Thank you for all your help!