with Lorelle and Brent VanFossen

Fixing RV Water Damage

Brent removes the wall of our slideout to repair water damage, photograph by Lorelle VanFossenWater damage from moisture inside and leaks outside can do amazing damage on an RV, especially an older one. Phrannie’s Handling Moisture in RVs article is a great indepth, step-by-step description of what to look for in every part and piece of your trailer, motor home, or van to stop the drips, leaks, rot, mold, and mildew. The fixes range from emergency fast fixes on the road to more indepth ripping and tearing.

If you can take something that’s leaking apart, do it. Then seal the mating surfaces and put it back together. A “seal” can be a gasket (like under the air conditioner) or an RV putty tape (doors, windows, roof vents and the like) or “Kool Seal Patching Tape” (lots better that RV putty tape). However, smearing globs of caulking all over everything is not sealing—and it doesn’t work.

“Caulking” is something you reserve only for things that can’t be fixed properly in the first place (or that you’re too lazy to fix properly). Caulking is also “insurance.” First you seal something (like a roof vent); then, for insurance, you caulk it to keep moisture from getting at the seal that does the real job.

“Coating” is the last step. After you’ve applied your sealing material and assembled things properly (without a lot of holes and gaps) and caulked (if necessary); then you coat the whole surface if appropriate.

Coating can be as simple as paint (prevents weathering, ultraviolet decay, rust and makes the thing look decent); or more complex (elastomerics that provide more durability and insulation) or more complicated and expensive (like custom-fitted vinyl sheeting—the so-called “Rubber Roof”).

Fixing: There’s no point in doing any of the above unless you first repair structural defects. Impossible to cover all variations, but here are some that many people don’t consider.


  • Sharon and Jim
    Posted July 8, 2006 at 16:51 | Permalink

    What do you do when you have no water pressure at all and the pressure at the outside faucet is good? We are stuck! Please help!

  • Posted July 9, 2006 at 1:22 | Permalink

    I’m sure you already checked, but just in case, check your hose. It can sometimes get blocked. Hook it to the outside faucet and run water through it to see that the pressure through the hose is good. Clean out all filters and screens in the hose and make sure there are no leaks or kinks.

    Once it is hooked back to the trailer, then check again to find out if there are any leaks at the connection.

    Check the connection. Are you using a water pressure regulator or reducer of any kind. There are small ones and larger metal ones that will reduce the water flow so that the water pressure will not hurt the pipes inside.

    If you have a water filter of any kind on the outside or inside of your RV, change the filter. Or at least check it, or bypass it so you can see if the filter is the culprit.

    Check basements and try to trace the water path inside and all around your RV to see if there is a leak somewhere that you are missing.

    Check every faucet you have. Make sure that the water pressure is the same in the bathroom as well as the kitchen. If you have an outside water faucet or shower, check to see if the water pressure is different there or better in one place than another. That might help narrow things down. Sometimes faucets or the pipes running to them need to be replaced because they are clogged with minerals or deposits. ALWAYS use a filter between the faucet and your water hose outside of the RV to keep the water coming into the house and into your RV as clean as possible.

    If your water heater is damaged in any way, it could clog up your hot water lines, but it shouldn’t impact cold water. Check to see if there is a difference between hot and cold.

    These are the typical things we do when we have a problem. Sometimes just disconnecting and reconnecting fixes things. We have an on/off valve on our water hose connection and sometimes we’ve forgotten to open it or didn’t open it all the way.

    If it was working fine before, then start at the outside faucet and go through everything step by step and maybe you will find it.

    If not, and you can’t move the RV to a repair and maintenance facility, or another spot in the campground to see if that makes a difference, then call a mobile RV repair guy. Explain your story as much as possible over the phone so they can get to work as soon as they show up. It might cost you $50 to $100 but they are really good at tracking things down. They will do what I just described, so make sure you go through that process at least three times in case you overlooked something before you call.

    I hope you fix it. Please let me know what it was.

  • Jim Worden
    Posted July 20, 2006 at 8:58 | Permalink

    Hi Lorelle….I read your response regarding the folks that could not get water at any of the taps inside their RV. You gave them good advise but missed one point I have found to be a culprit in similar situations. Just recently, during a trip to Florida in our motorhome, The people next to us in a one year old motorhome had the same problem. No water inside. Because I am in the RV water business and am well versed about these issues, I offered to take a look. Everything was hooked up properly and water pressure/flow was good up to the inlet to the motorhome. I went inside and there was not a drop of water at the bath or kitchen sink. There was a trickle in the shower. I unscrewed the screen from the kitchen sink faucet and, low and behold, it was packed solid with algea. So was every other outlet in the unit. The owner was horrified. This is not an uncommon problem. This can happen when contaminates get into the water system. We have been educating people on the importance of regularly cleaning the RV water system with soap and bleach and using a good quality filter system at the point of entry. The quality of the water found around the country can range from good to horrible. The truth is, we are to trusting and complacent. We need to take control of the water coming into our RV’s.
    We market a high quality water filtration system and have a full range of “How To” articles on managing RV water. I would be more than happy to provide any reader with information and instructions on how to maintain the RV water system and keep it clean. Just send me an email request. There is no charge for this information.

  • Posted July 20, 2006 at 9:22 | Permalink

    Thanks for the information and I may take you up on your offer soon.

  • Sara Fagan
    Posted August 7, 2006 at 1:31 | Permalink


    I have a question for you, or anyone else that may have an answer. We inherited a 1973 Dodge motorhome, not sure the model, from a friend. It has sat for 10 years, and, amazingly, most things have not been too much of an issue. The biggest problem is that this is our first RV, and our friend does not remember much about how things work! We finally managed to get the pilot light on the water heater working, and the water heater itself, but can’t get water out of the heater to the faucets. I read your posting on algae, and thought maybe that is the problem–there is a yeast smell (smells like bread dough) coming from the water drained from the water heater drain outside. So, I need info on how to clean it out. The cold water works fine, and there is water pressure through it if we bypass the water heater. But, if the water goes through the heater, you can hear water going in, it heats up, and nothing comes out of the hot water line.

    My husband and I are debating on what could be the issue. We also see two pipes that drop down below the floor boards (you can see them underneath), one with a male end and one with a female end. The hot water line to the shower and sink come from the male end pipe, and the other pipe goes into (we think) the water heater. Is this a winterization issue? I mean, could someone have taken off the connecting pipe underneath for winterization? If so, should hooking them together fix the problem? Hopefully, it is something silly like that, and we can fix it easily.

    Thanks for your input! It is so nice to be able to search for topics like this and get helpful information!


  • Posted August 7, 2006 at 10:42 | Permalink

    To get an answer from Jim, you’d have to talk to him directly, but he didn’t leave a website. Sorry.

    As for an answer from me, it sounds like water is getting “into” the water heater but not coming out? The odds are that it had water sitting in it and it is filled with minerals and possibly rust. Bad news.

    For a cheap possible fix, I recommend a good rust and hot water tank cleaner available from decent RV supply stores. They will have a recommendation on what product to use.

    It sounds like you have a plumbing issue, though. Something is stopping the water from leaving the hot water heater at the exit point. If you are mechanical, I recommend you drain all the water out of the motor home (NEVER turn on the hot water heater without water in the tank – filled!) and disconnect the pipes going to and from the water heater, since you don’t know which is which. You might have to remove the water heater carefully and check it disconnected from the vehicle. Depending upon your configuration, it might be an easy job, it could require a professional.

    If it is the original hot water heater from 1973, don’t mess with this any more. Replace it. And replace it with a gas/electric model. It will probably leak or have other damage anyway, so don’t waste time to patch it when it will probably break when it gets hot anyway.

    The pipes through the floor boards have nothing to do with winterization. The process of preparing your vehicle for storage is to drain all the water out, and “blow out” the water from the system, or put a non-freezing and non-toxic chemical in your water supply that will keep the water from freezing. The pipes were probably disconnected for other reasons.

    If no water comes out of the disconnected pipes, then I don’t know what this is. If it needed to be connected, then water would flow out of the hot water heater looking for an escape.

    I honestly recommend you haul this thing to an RV expert/service center, and not just because of this issue.

    An RV of any kind sitting for even a year often has many issues you will never see until you are driving down the road and looking through your rear view mirror to see cars swerving to miss the parts and pieces dropping from your vehicle. 1973 is OLD. No matter how long it sat, it’s old. Tires rot, axles rust and sag, and engine parts and hoses – ARGHH! They rot. I just had to replace all of them in a 1988 motor home that also sat, but not that much.

    All pipes, hoses, gears, refrigerator, AC, and many electrical wires, parts, and pieces probably need replacing, if not thorough inspection by experts. Our trailer is a 1994 and it has major problems just because of age. You could have micro leaks in the roof, window, or seams and water damage you can’t even imagine.

    I don’t mean to scare you, but before you spend one night in this thing, make sure that it is seriously inspected. Mold, mildew, leaking gases, all can kill you.

    I know this isn’t the quick fix help you needed, but trust me, been there, done that, suffered for it. A motor home that age is nothing to mess around with, no matter how clean the rugs are.

  • Jim Worden
    Posted August 9, 2006 at 19:27 | Permalink

    Hi Lorelle,
    I just this minute returned to your web site and found your posting to me along with Sara Fagan’s. Please accept my apologies for not responding sooner.
    Your advise to Sara regarding her water heater is spot on. I would suspect that after ten years in storage, the water heater is probably plugged solid with rust and corrosion. Save your self a lot of trouble and replace it. I would have the water, electrical, propane and sewer systems checked by a good shop at the same time. Water incursion into the RV is a curse we all must watch for. I would carefully examine and replace caulking around all roof openings and windows as soon as possible.
    I would be happy to send you instructions on how to sanitize and maintain the fresh water system and how to store fresh water properly. Good Luck!!!

  • Posted August 9, 2006 at 22:54 | Permalink

    Thanks, Jim, for responding and checking in.

    As a general policy, I don’t allow emails to be published on my website, as that is risking privacy violation issues, though I will forward any questions to you.

    Do you guys have a website where I can better direct people who have questions and from where they can contact you directly? That would be really helpful. If not, can we talk. ;-)

    Thank you again!

  • Jim Worden
    Posted August 10, 2006 at 9:10 | Permalink

    Hi Lorelle…..Our web site is about to be completed and released. http://www.covesystemsinc.com
    It may be a few more days to get all the pictures placed properly, but we are close. Although we will be marketing water processing equipment, my concern is to educate the RV world regarding water while on the road and taking care of the on-board water system. If I sell a filter along the way, so much the better. Thank you and take care.

  • Posted August 10, 2006 at 10:32 | Permalink

    Thanks again, Jim. And we look forward to your new site. Again, it is MY policy not to permit private information in comments. The risk is too great. I have stored the information, though, for future reference and referrals. I highly recommend that your “site” be or have a blog more than just a static website, as they are near to useless nowadays. If you want to inform, inform regularly with frequent tips and articles, and a blog is highly interactive. A website is not. You can learn more here. I’m a little bit of an expert on this – you on water. What a pair! ;-)

    Good luck!

  • Posted June 20, 2008 at 10:17 | Permalink


    Why would you think I could help you? Contact the manufacturer or look for a support forum that handles boat issues. We don’t boat. Good luck.

  • Donna
    Posted May 20, 2009 at 15:23 | Permalink

    Our rv water tank is draining out the over flow until it’s empty. (mostly only while the pump is on)Do you have any ideas?

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