Is it really a Water Pump Problem?

[ComerD]

Here is the issue: For the past few months I have had an intermittent problem with the fresh water tank filling by itself even though I had the city water fill valve turned to the not fill position. My fix for that problem was to cycle the city water valve back and forth a few times and that seemed to stop the inadvertent filling of the fresh water tank.

Fast forward to the present. After getting set up at our winter location in Mesa Spirit RV resort here in rain soaked Mesa AZ I went to play some pool and upon my return I noticed a very large water pool around my fresh water bay. Upon closer inspection I noticed that the fresh water tank overflow hose was pouring out water onto the ground. When I looked at the fresh water tank it was full and running over. I turned off the city water source and drained about half of the water out of the tank and then turned back on the city water source. I also cycled the city water fill valve a few times as that always seemed to fix the problem.

Fast forward another hour: I went back to inspect the fresh water tank and damned if it wasn't full again and starting to overflow. Time to get serious now. Just so happened an RV repair person was in close proximity and he agreed to come over and take a look. After discussing the problem we both thought that the City Water fill valve could be leaking water back into the fresh water tank. Sounded reasonable! I had him replace the valve. All seemed fine and he was off to another job.

Fast forward two more hours: I went back to the water bay just to check things out and low and behold the fresh water tank was full again and beginning to overflow. ARGGGGGG. I call the RV tech back and he made some calls to his boss for some troubleshooting pointers. They both agreed that the water pump was bleeding water back into the fresh water tank and needed to be replaced. What??? I told them to hold off as I wanted a "second opinion" from the experts on the forum. So, here are some of my questions for you RV geeks out there:

1. I am not aware that the water pump has a dedicated "feed" to the fresh water tank. How could the water pump be leaking back to the fresh water tank?

2. If it is the water pump is there any adjustments that could be tweaked to fix the problem?

3. If I do need to replace the water pump what is a good recommendation for a replacement.

Sorry for the long dissertation. We are not in a big hurry to get this fixed as we are working just fine off of the water pump without city water. Thanks in advance.
http://www.irv2.com/forums/images/smilies/blush.gif
Comer

[757driver]

Originally Posted by ComerD

Here is the issue: For the past few months I have had an intermittent problem with the fresh water tank filling by itself even though I had the city water fill valve turned to the not fill position. My fix for that problem was to cycle the city water valve back and forth a few times and that seemed to stop the inadvertent filling of the fresh water tank.

Fast forward to the present. After getting set up at our winter location in Mesa Spirit RV resort here in rain soaked Mesa AZ I went to play some pool and upon my return I noticed a very large water pool around my fresh water bay. Upon closer inspection I noticed that the fresh water tank overflow hose was pouring out water onto the ground. When I looked at the fresh water tank it was full and running over. I turned off the city water source and drained about half of the water out of the tank and then turned back on the city water source. I also cycled the city water fill valve a few times as that always seemed to fix the problem.

Fast forward another hour: I went back to inspect the fresh water tank and damned if it wasn't full again and starting to overflow. Time to get serious now. Just so happened an RV repair person was in close proximity and he agreed to come over and take a look. After discussing the problem we both thought that the City Water fill valve could be leaking water back into the fresh water tank. Sounded reasonable! I had him replace the valve. All seemed fine and he was off to another job.

Fast forward two more hours: I went back to the water bay just to check things out and low and behold the fresh water tank was full again and beginning to overflow. ARGGGGGG. I call the RV tech back and he made some calls to his boss for some troubleshooting pointers. They both agreed that the water pump was bleeding water back into the fresh water tank and needed to be replaced. What??? I told them to hold off as I wanted a "second opinion" from the experts on the forum. So, here are some of my questions for you RV geeks out there:

1. I am not aware that the water pump has a dedicated "feed" to the fresh water tank. How could the water pump be leaking back to the fresh water tank?

2. If it is the water pump is there any adjustments that could be tweaked to fix the problem?

3. If I do need to replace the water pump what is a good recommendation for a replacement.

Sorry for the long dissertation. We are not in a big hurry to get this fixed as we are working just fine off of the water pump without city water. Thanks in advance.
http://www.irv2.com/forums/images/smilies/blush.gif
Comer

If your water pump is original then it is most likely the Shurflo 4008 water pump which has been problematic with internal leaks and filling the fresh water tank.

I would eventually change that pump out for something better such as a Flojet or the Shurflo 4048. For the time being you can install a check valve on the fresh water tank side of the water pump and it will stop the water tank filling through the water pump.

[Marcosdad]

There is a check valve in the pump designed to prevent back flow to the tank. You can check it by (pump off) disconnecting the input side of the pump. With city water on, you should get NO water back through the pump. If you do, some have replaced the check valve, and some have replaced the pump.

[brobox]

Lots of posts with that problem, this post has lots of pictures of the easy fix.
http://www.irv2.com/forums/f278/fres...ve-386640.html

[DebbieMH]

Changing the pump will solve the problem. I've been all the routes and should have just changed the pump to begin with. Haven't had a problem since I did .....

[Gary.Jones]

Comer

You have most of the story here in the responses you have gotten so far, but if you will search using the search box at the top of the page and enter ENTEGRA followed by the search terms you want, you will find those long threads on this same issue. This has been discussed frequently. If you go through those past threads, you will get a fuller understanding of the various problems and various fixes.

There are other causes as well as other remedies to this problem other than replacing the water pump. That is one way. And it has worked for some, and done absolutely nothing for others. There are also other types of better constructed check valves that can be added to the system in addition to the one that is built into most quality pumps.

Gary

[fla tom]

I had that problem , changed the pump and still had that problem...replaced the water pressure regulator and problem solved.

[brobox]

Originally Posted by fla tom

I had that problem , changed the pump and still had that problem...replaced the water pressure regulator and problem solved.

My tank overfilling was also a non adjustable Watts pressure regulator allowing 70 psi to the MH.