Noob Question: Standing Water in Drains

[Marlinsonthemove]

In preparing our2022 Keystone Springdale 220RD for storage I thought I drained every bit of water that existed. But I went to the storage facility the other day because I had just purchased new drain screens for the kitchen and bath sinks, and the shower. When I looked down in to the drain in the kitchen and shower I saw standing water about 4" down the drain! How is that possible when dumped all the tanks and opened all the low point drains? PLUS, we've never even used the shower! I'm at a total loss here. Any direction would be appreciated!

[wiredgeorge]

Originally Posted by Marlinsonthemove

In preparing our2022 Keystone Springdale 220RD for storage I thought I drained every bit of water that existed. But I went to the storage facility the other day because I had just purchased new drain screens for the kitchen and bath sinks, and the shower. When I looked down in to the drain in the kitchen and shower I saw standing water about 4" down the drain! How is that possible when dumped all the tanks and opened all the low point drains? PLUS, we've never even used the shower! I'm at a total loss here. Any direction would be appreciated!

Look under the sink. There is a P trap and you can drain all the drains and such but the P traps will still have water in them. That is why folks who winterize pour antifreeze into the drains with such P traps. There is also one under your kitchen sink.

[chuckster57]

Welcome to the forum

All your standing water is in drainpipes and it’s there to prevent wate tank odors from escaping into the cabin of the RV. As George said, those that winterize will pour antifreeze in them and the toilet bowl.

[dutchmensport]

Posts above are absolutely correct ... P-traps and RV antifreeze down the drain.

However, I remove my p-traps under the sinks and dump them out. I then use a rubber band with a plastic grocery bag and cap off the exposed drain to keep smells from coming up from the holding tank. In the Spring, or when I unwinterize, I'll hook the p-trap up again. I've been doing this for years now on all my previous travel trailers too.

The only exception is the bathtub or shower. I don't have access to them, so I pour the RV antifreeze down that drain pretty liberally.

If you blow your lines in the winter, you still need to put RV antifreeze down all your drains to keep them from freezing in the P-traps too. (or remove the p-trap and pour the water out).

[Devin_Noel]

Some RVs have a HEPVO valve in them. It's basically a balloon with a 2nd hole in it inside a piple. It acts a 1 way valve so sewer gasses can't get back up the plumbing. Everything else, including every drain in your house has a P trap in it for the same purpose. Trap a slug of water in the pipe so sewer gas can't get back up the drain.

I pour a bit of RV antifreeze down the drain after getting all the cold & hot plumbing. Easier than trying to drain them & only takes $0.50 worth of anti-freeze.

[madweazl]

Originally Posted by Devin_Noel

Some RVs have a HEPVO valve in them. It's basically a balloon with a 2nd hole in it inside a piple. It acts a 1 way valve so sewer gasses can't get back up the plumbing. Everything else, including every drain in your house has a P trap in it for the same purpose. Trap a slug of water in the pipe so sewer gas can't get back up the drain.

I pour a bit of RV antifreeze down the drain after getting all the cold & hot plumbing. Easier than trying to drain them & only takes $0.50 worth of anti-freeze.

I had never even heard of the HEPvO system. That is pretty cool.

[Devin_Noel]

Originally Posted by madweazl

I had never even heard of the HEPvO system. That is pretty cool.

Works well. Pretty common on the small fiberglass shell trailers & others that are a lot more space & height constrained. Seems to have shown up a decade ago or something & really caught on in the past 5+ years.