Fresh water tank filling and overflowing during full hook-ups

[Travelers]

I have a 2015 Jayco Whitehawk24RKS. On roughly 2 out of 20 trips, with full hook ups, our fresh water tank fills up and overflows after about 8 hours. I took it to dealer after first incident but as fate would have it, it wouldn't do it for them. It is again doing it this weekend. It just went off of warranty a few days ago.

1- any idea what is happening.
2- can I run the water pump to drain the fresh water tank for showers/etc.
While still with full hook-ups.

Thanks for any assistance.

[silverark]

Mine did that also. Here's what I found. There is a check valve inside the pump that stops water back filling into the tank. It was stuck open so I removed the pump, removed the screws on the pump head. On the inside is a small round valve about the size of a quarter. I just touched the valve and it snapped closed. I put it all back together and no problems. I did order a replacement check valve from amazon to keep on hand just in case. Easy job, just tight getting the pump out of a tight spot.
One thing you may notice is while only using the fresh water tank and pump, in would not hold pressure and would cycle on occasion about every 30 minutes. This is a sign that the checkvalve is leaking if you have no other leaks in the coach.

[silverark]

Below is what the checkvalve looks like. Hope this helps.

https://www.rvsupplyparts.com/images..._94-800-03.jpg

[Sundancer330]

I did it the easy way, cut the pex after the pump and press fit this check valve in place, no tools needed.

https://www.grainger.com/product/1DA...170525181859:s

[Travelers]

Thank you very much for the NFL. Do you by chance have the check valve part(s) number. Thank you.

[LiftedAWDAstro]

Another option is to just use the pump once the tank fills up. Shut off the city water supply at the spigot. Then pump the tank until empty and start using the city water after that. Maybe the check valve is sticky due to minimal use.

[Travelers]

Sun dancer330, by chance could you post a photo of the world nstalled check valve outside the pump. I went ahead and ordered the part. Thanx a million.
Or you can send it directly to me at larryplants@yahoo.com.

[Sundancer330]

Originally Posted by Travelers

Sun dancer330, by chance could you post a photo of the world nstalled check valve outside the pump. I went ahead and ordered the part. Thanx a million.
Or you can send it directly to me at larryplants@yahoo.com.

Next trip to the trailer I will get you a picture.

[Travelers]

Thank you very much.

[schrederman]

This is a common problem. That little check valve gets stuck sometimes. All 3 of our TT pumps have done this at times. I always check tank levels even when we are hooked up to city water. If the fresh tank is filling, I pump it out. This usually un-sticks the check valve and no more problem until a few trips down the road. Really nothing to fix, usually. I have had to replace the check valve on a friend's pump... and it's easy. The replacement stuck a couple of times but turning on the pump released it.