Community Forums

chasfm11 · 08-16-2005, 03:44 PM

When switching from city water to use our fresh tank with the pump, the pump will run but not pump water. I read through past forum posts, especially those about the water tank fill valve being open and carefully checked for that condition. While it is possible that there is a bad seat on the water tank fill valve, I made sure that it felt tight. I'd also seen information about a checkvalve but haven't been able to locate that in our system.

I was successful at getting the water to flow by opening the outside shower valves. After a few seconds, I got a trickle of water and then heard the pump increase in noise volume and got a good surge of water. Once this happens, the pump will work faithfully until I hook up the hose and city water again.

Is this a checkvalve problem and, if so, what does the checkvalve physically look like? Is it possible that it is just a bad seat washer inside the fresh water tank fill valve? Are there other possibilities?

Thanks,

Charlie

chasfm11 · 08-16-2005, 03:44 PM

When switching from city water to use our fresh tank with the pump, the pump will run but not pump water. I read through past forum posts, especially those about the water tank fill valve being open and carefully checked for that condition. While it is possible that there is a bad seat on the water tank fill valve, I made sure that it felt tight. I'd also seen information about a checkvalve but haven't been able to locate that in our system.

I was successful at getting the water to flow by opening the outside shower valves. After a few seconds, I got a trickle of water and then heard the pump increase in noise volume and got a good surge of water. Once this happens, the pump will work faithfully until I hook up the hose and city water again.

Is this a checkvalve problem and, if so, what does the checkvalve physically look like? Is it possible that it is just a bad seat washer inside the fresh water tank fill valve? Are there other possibilities?

Thanks,

Charlie

08-16-2005, 08:24 PM

...air locked....need better flow by lowering part of the water supply hose to pump to keep from air building up....makes me crazy too....but I fixed mine by getting rid of the pump and going to compressed air system.....no more problems.....geofkaye

DriVer · 08-16-2005, 08:33 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by chasfm11:
Are there other possibilities? </div></BLOCKQUOTE>Charlie, Just thinking here but how'z your inlet screen? I found that mine was pretty dirty (brown film) and I would be suspect that if may have occluded the flow to my pump.

Screen is clean now and the pump seems to run better.

RV Wizard · 08-16-2005, 11:57 PM

If the pump is running but not pumping look to the inlet side of the pump. If it is not running there could be a pressure airlocked and you need to look on the discharge side of the pump. It may be that the pressure switch on the pump itself is starting to fail. The check valve should be a the inlet of city water, another at the water heater and you could have one at the discharge side of pump before city inlet connects to system. Good luck and let us know what you find.

chasfm11 · 09-07-2005, 12:21 PM

Here is a update.
1. The pump always runs. When it is in the failing condition, it just doesn't pump water.
2. There is no check valve on the back size of the hose inlet. There is just a joint to connect that fitting to the rest of the system.
3. Once the pump operates correctly, it continues to do so over many days and being turned off and on at the switch panel.
4. When it fails, it is always after I disconnect from city water. The last two times, I've been successful at getting it to start pumping by opening the outside shower. I discovered this by accident when the cleanout water was not available at a dump station. After the water starts at the outside shower, I must still let one of the inside faucets run for a minute or two while it spits and air comes out with little water. When the water start flowing and the pump is running with the heavier "pumping" noise, the flow is good and the pump shuts off and restarts with the faucet.

I suspect this is somehow operator error for the way that I'm disconnecting. Any thoughts would be appreciated.

Kirk · 09-07-2005, 03:55 PM

It sounds as though you are somehow getting an air lock in the system. Since the outside shower is probably near the city water connection it may be that your air is somehow comming from it. I would try using a hose plug screwed into the water connection to prevent any air entry into the system to see if that will help.

chasfm11 · 09-08-2005, 04:17 AM

Thanks for your suggestion, Kirk. I think that I tried to do exactly what you suggested but without good results. I have a "Y" connector that I always use to attach my hose to the spigot. When I disconnect, I shut off the "Y" connector valve for my hose before shutting off the water at the spigot and then disconnecting from the spigot, trapping the water and pressure inside of the hose. I simply coil the hose up in the compartment and close the door. I would have thought that this would prevent any air in my system but apparently not.

I have also tried relieving the pressure in the hose but not draining it. The results were the same. The outside shower is near the hose input and is much lower than the rest of the system. I thought initially that I might somehow be sucking air in via that shower but have not been able to prove to myselt that that is what is happening. I have no water leaks anyplace before disconnecting the city water hose so I'm assuming that there is no place to suck in air. I have a whole house water pressure regulator and sediment filter in the hose line and have checked them both for leaks as well.

Charlie

Gary RVRoamer · 09-08-2005, 05:18 AM

The city water inlet check valve is usually part of the inlet fixture itself, not a separate component. To replace it, you probably have to replace the inlet (not expensive and usually easy enough to do).

Your symptoms sound like an airlock, though. The pump cannot build up pressure nor can it move water past the air bubble, so it runs and runs. The outside shower is often the lowpoint drain in the system, so opening it flushes the line and releases the air bubble. Another faucet would probably do as well but would take a whole lot longer.

When you connect an empty hose and then turn on the site's water spigot, you push a hose full of air into the Rv system. My guess is that some of that air is being trapped against the pump outlet. Try opening the valve that fills the tank before connecting the city water hose (that let's any air push into the fresh water tank, where it is vented). See if that eliminates the problem later when you disconnect and switch to pump. You really shouldn't have to do that, but it would help pinpoint the problem. There may be a low (or high) spot in the tubing that is trapping enough air to cause the trouble, Re-routing the line can solve it, if that is it.

chasfm11 · 09-08-2005, 09:53 AM

Gary, first, thanks for your reply and second - Right on! I was assuming that the problem was created during the disconnection process. It wasn't. The hose (or when I needed more length - hoses) full of air were somehow being driven into the system at connection time in such a way as to prevent the pump from sucking water out of the tank. I still don't understand why this is true but it is. I could replicate the failure at will today or make it go away by disconnecting the water hose at the RV end and filling it with water (driving out the air) before re-connecting it. The switch over to pump was almost instantaneous after disconnecting/shutting off the city water.

I would have thought that all of the air in the hose would have been discarded through the first faucet turned on inside after connection. Now I know that it isn't and can make sure that take proper steps to prevent the air pocket.

Thanks again.

Charlie