Problem Filling the Fresh Water Tank on Travel Trailer

by Jim Jenkins
(Gig Harbor, WA)

I have a 98/99 24 ft. Prowler travel trailer (first year). I drained the tanks for the winter and now I can't get the fresh water tank to accept water. It just back-flows. I'm guessing there's some kind of anti-surge valve that's stuck closed. If so, how do I get it unstuck?

The owner’s manual is no help at all.

ANSWER: Greetings Jim thanks for submitting your question on our Ask An RV Question Page.

I do not believe your problem has anything to do with any type of Anti-Siphon Valve. Here are a couple of things to look at. First make sure that any winterizing valves you have on your RV are in the non-winterized position.

This problem could also be caused by a blocked or kinked air vent hose on your fresh water tank or on the water connection itself so make sure to check those.

Leave your RV repair bills to us—Good Sam Extended Service Plan

In some cases you may even find a shut off valve on the air vent hose or tubes themselves you need to make sure that these valves are in the open position so air can escape from the fresh water holding tank while the water is flowing in.

You might also want to use an RV Water Tank Filler Attachment on the Drinking Water Hose you use to fill up your fresh water holding tank. This attachment has a tube on the end that slides into your water tank fill connection and will possibly help stop the water blow back you are experiencing.

Other than that I really cannot tell you what else to look for as I cannot look at how your fresh water holding tank fill system is plumbed and if someone has installed some aftermarket fittings or valves on it.

I hope this helps.

Do you have any suggestions or comments on this topic? You can add them to this page by clicking on the "Click Here To Post Comments" link located near the bottom of this page.

Protect your RV and your family while on the road: Join Good Sam RV Emergency Road Service Today and save!

Happy RVing

RVing Al

Don't Forget To Visit The Everything About RVing Stores.  If It Has To Do With RVing And The Outdoors The EARV Stores Have What You Are Looking For!

RV Accessories - Sporting Goods - RVing and Travel Books and How To Videos - Kindle Accessories and Books - The RVers Gift Shop - The RVer Mall - Buy or Sell An RV - The NASCAR Collectibles Store

Comments for Problem Filling the Fresh Water Tank on Travel Trailer

Average Rating starstarstarstarstar

Click here to add your own comments

Back flow when filling water tank
by: Anonymous

The smaller, clear tube near the intake opening was clogged with bug larvae/ / cacoon. I used a long stick to push out and then flushed with water. Problem solved!

Fresh water filling problems
by: Gary from Montana

I finally figured out an easy fix to my problem of filling and a constant air lock causing water to come back out the fill neck. I never could get my fresh water tank completely full. Had to fill with just a trickle coming out the hose, could take all day.

My water fill is on the very rear of my 30' 5th wheel. Now I lower the nose of the camper as low as possible, raising the rear and it fills fine even full blast out the hose.

fresh water problems
by: Anonymous

While filling the rv with fresh water, the water is going into the holding tank. dont know why.

Filling fresh water tank.
by: Anonymous

The air is not able to leave your tank as you fill it. This is causing the water to be pushed out of your tank.

Open all faucets in trailer to allow the air to escape as you fill your tank. Your overflow line may be stopped up also.
You can take it off at the tank to let air flow out, then reattach it after the tank is filled.

Click here to add your own comments

Return to Ask an RV Question.