2022 avalanche fresh water being filled up while hooked to city water

[Stevestrailer]

My trailer is hooked up to city water. The selectors are set in normal. The fresh water keeps filling up. I’ve heard there is a check valve in the water pump that will cause that. Wondering if there are any tests to make sure that the pump check valve is bad? I’ve also seen people add check valves to the pump. My pump doesn’t have the regular Pex lines so would a regular plumbing check valve work? I’m thinking of a female to male version then I could hook it on the output and hook the hose onto the check valve. Thanks in advance for the help!

[JRTJH]

You stated that you are hooked up to city water and the water pump is "leaking through" to fill the fresh water tank. You didn't mention whether or not you are also using a water pressure regulator (NOT A RESTRICTOR DEVICE) on the city water input to your trailer. If you are using a restrictor device (like the first photo), once the water demand stops (when you turn off the faucets in the trailer) the pressure will creep up to match that in the campground water supply. If you have a water pressure regulator (similar to the second photo) it will always maintain pressure at the setting on the regulator and not allow higher pressure into the trailer....

Are you using a water pressure regulator, similar to the second photo? If not, that may be the only thing you need to change to "fix the fresh water tank filling problem".....

[Stevestrailer]

Yes it’s actually the exact same as the second one

[JRTJH]

If you're using a regulator and still getting backflow through the water pump, you may have some debris trapped in the pump diaphragm. During trailer construction, when the line workers drill holes in the fresh water tank to install fittings, some of those drill shards fall into the tank. They can get sucked up into the water pump and cause the diaphragm (which is the backflow device) to not properly seal, allowing water to seep "backwards through the water pump diaphragm".

It's easy to take the pump apart and clean out anything in the diaphragm cavity.

[Stevestrailer]

So far it looks like tearing apart the pump and cleaning it out seems to worked thank you!

[JRTJH]

Originally Posted by Stevestrailer

So far it looks like tearing apart the pump and cleaning it out seems to worked thank you!

What did you find inside the pump? Typically, it's a couple (2 or 3) small shards of white plastic from the water tank that get picked up in the supply line and stuck in the pump.

You can eliminate any future problems from "trash" by installing a strainer on the inlet side of the pump. It's an "easy plug in modification", just undo the inlet fitting, plug that fitting into the strainer and plug the strainer into the pump.

IMO, installing a strainer on your water pump is one of the best upgrades you can make. https://www.ebay.com/itm/12445592605...3ABFBMrP-OlPZi

[Stevestrailer]

There really wasn’t much junk in there that I could see. There is a strainer on it already that came with the unit

[govols380]

Originally Posted by JRTJH

If you're using a regulator and still getting backflow through the water pump, you may have some debris trapped in the pump diaphragm. During trailer construction, when the line workers drill holes in the fresh water tank to install fittings, some of those drill shards fall into the tank. They can get sucked up into the water pump and cause the diaphragm (which is the backflow device) to not properly seal, allowing water to seep "backwards through the water pump diaphragm".

It's easy to take the pump apart and clean out anything in the diaphragm cavity.

That might be in my future; I think I saw similar issue on our inaugural run, but was also using a restrictor rather than regulator. We'll see in a couple of weeks.

[govols380]

Will the pump issue clear if one uses the fresh tank and pump for a camp or two?

[bobbecky]

Not necessarily, because the rubber check valve may be deformed and nothing you do will fix it. I've posted this several times, but many years ago, we were at a rally, not near an RV store, and our fresh tank was filling and overflowing due to the check valve on the pump not holding water. I went in to a small hardware store and purchased a 1/2" Sharkbite check valve and cut it into the PEX on the pressure side of the pump, and that solved the problem. The check valve is still there, even after replacing the pump years later. In the photo, it is the brass device near the lower center of the photo.