Skip to Content

RV Plumbing Leak Troubleshooting & Repair – Practically For Free!

RV Plumbing Leak Troubleshooting & Repair – Practically For Free!

We demonstrate lots of RV repairs. This time, we’ll show you how we diagnose and repair a problem, saving ourselves a trip to the shop.

Special Bonus!! We’ll be answering your questions live on the air on The RV Show USA on November 1st! That’s right… we’ll once again be joining our friend Alan Warren “The RV Guy” on his nationally syndicated radio show – the only one about RVing in the country. Our topic this time will be this video and the tips and tricks we use to diagnose and repair things on our own RV.

CALL US LIVE ON THE AIR on The RV Show USA on Wednesday, 11/1/17 — (855) 296-7469. The show starts at 7 pm Central Time, and Alan will be opening up the phones for you to call in at about 7:30 (we’ll be on for the full hour). We’d love to hear your comments or questions!

We’d love to feature your questions! After watching the video, you can submit a question related to it in the comments section below, or on The RV Show USA Facebook page. Alan will then ask us as many of those viewer-submitted questions as we have time for live on the air next Wednesday evening, November 1, 2017.

We’ll be live at 8pm Eastern / 5pm Pacific. Visit The RV Show USA website to find out if your local station carries the show. You can also watch the live Facebook feed, broadcast from the show’s studios in Texas (or view it later on).

If you miss the live show on November 1, you can still hear the archived version at any of the following locations:

If you missed us on the October 18th broadcast of The RV Show USA,
you can listen to both of our segments on their podcast here.

This video is a great example of our very favorite type of DIY project. It was fun to sleuth out the problem, surprisingly easy to complete, incredibly inexpensive, and every bit as good (or better!) quality work than a shop would have done. Best of all, we took what could have been a really challenging problem to figure out, and made quick work of it. Talk about the satisfaction of doing the job ourselves… this is the very definition of it! :)

Some problems are actually easier to figure out on our own than by a trained tech. That’s because some things just take a bit of observation, time, research and thought to diagnose. The last thing you want your tech to have to do is take too much time to figure out the problem, since diagnosis time is charged at the same exorbitant hourly rate that the actual repairs go for.

In this particular case, there’s also a good chance that a tech could have gone for a quick, easy, seemingly obvious (but more expensive) fix…. the wrong fix!

Instead, we did the entire job ourselves, for free! The only costs we might have incurred were a replacement part and the special tool to install it. But since we already owned the tool, and had the small, inexpensive replacement part on hand in our parts bin, we literally got the job done for free!

Recent & Related Videos:

Featured & Related Products:

We'd Love It If You Shared This!

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Bob Sanders

Friday 27th of September 2019

Hi Guys, I have an 07 Ventana, with a tank fill valve issue, where did you find your replacement valve? I also want to replace the valves on the hot water tank bypass as well as the winterizing valves that isolate the lines, so if you know where I can locate these valves it would be appreciated. Thanks, Bob


Friday 27th of September 2019

Hi Bob! Always great to hear from a fellow Newmar owner. Unfortunately we're sorry to report that last we checked, Newmar did not have those valves available any more, and they've ben replaced with a similar, but not identical part. We just happened to have a couple of spares in our spare parts bin, because we removed the water filter under our kitchen sink when we installed our Acuva system. The bypass for that original filter included a couple of the exact same valves, which we'd kept. So it was just a fluke that we had them available for re-use. We'd suggest contacting Newmar's parts department to see if there's been any change in availability, and if the replacement part they offer will work for you.


Tuesday 12th of February 2019

Hi Kevin! We have indeed used SharkBite connectors before, and they are excellent and reliable. They are however fairly expensive, especially in comparison to PEX crimp rings. And you probably will still need a PEX cutting tool to get it to the correct length/position to install the SharkBite connector. While the PEX crimping tool is fairly expensive, buying one does allow you to have that in your toolbox. That was a plus for us, as we like having it around since the entire RVC’s plumbing system uses PEX. One of the reasons we went with PEX rings was because we generally prefer to put the RVs systems back exactly as they were whenever possible during a repair. That said, if you decide to go with SharkBite products, you can’t go wrong. They’re pretty cool, and work very well.

Shirley & marv

Monday 7th of January 2019

We have water dripping off the back underside of our Jayco 27.5. We checked for leaks near the water heater, shower, bathroom sink and kitchen sink. The outdoor shower fittings are not leaking. We are hooked to city water. The water on the underside is dripping near the fresh tank area, but there is no water in the tank. Any suggestions for us to continue? We are camping for two months away from home and the camper is less than a year old!


Monday 7th of January 2019

Hi Shirley & Marv! First off, so sorry to hear that you're having this problem, especially with such a new unit! Tracking down the source of water leaks can be a bear, as the water can flow and follow hoses and wires and show up someplace pretty far from the source. The fact that the fresh water tank is empty, certainly eliminates that from the equation (assuming it's intentionally empty... and not because all the water has leaked out of it! ?). Simple question... but since you're on city water, it bears asking... are you using a pressure regulator for your city water connection? Hooking up directly to a spigot could mean that you are over pressurizing your RV's plumbing system, and the water could be coming out of a fitting somewhere that can't take the pressure.

Unfortunately, we don't have anything more specific to tell you to do other than to try drying things out and seeing if you can find where the source is coming from. Barring that, since your unit is less than a year old, it should still be covered by warranty... so maybe you can find a local Jayco dealer who'd be willing to take a look at it (not that you want to spend time from your camping trip at a dealer, but if they can fix it, it might be worth it!).

You could also try posting your question in the Jayco Owner's forum over on ( ). It's free to join, and free to post, and it's your best bet to find out if there's a known issue with your particular floorpan/year/model that maybe someone else has already dealt with, so they could give you some more specific direction on where to look!

Sorry we can't be of more help, but please keep us in the loop as the repair unfolds.

jeffrey & kim

Thursday 7th of June 2018

hi gents, we've enjoyed & appreciate your videos, being new owners of our 2002, 43', newmar mountain aire tag-axle coach !

when your faulty valve was causing the water pump to cycle due to pressure loss, did you have any water leaking from the faulty valve onto the pvc tray below your water control panel ? we have been hooked up to city water for 2 months (travel working) & recently noticed the coach was dripping onto the ground in several places along our undercarriage, which we had been attributing to the several weeks of on/off rain & standing water causing condensation on the metal undercarriage. to our dismay, when retrieving items in the through-body compartment, we discovered the carpet, and several items in the basement, were saturated, but the slide-out trays & items have always been dry (fortunately). to rule out the water problem being caused by a roof leak making its way to the basement due to the rain, we figured a quick test of the plumbing system would be in order. we turned off the city water & turned on the water pump, since we had a full fresh water tank (we bleach cleaned the fresh water tank/plumbing system during our travel, as you recommended) and the pump worked beautifully, but discovered it short-cycled every 20 seconds when there was no water demand ... uh oh. since our water control compartment is bone dry, there must be something more significant going on. have you notice water leaks being mostly due to valve failures, rather than pex connection failures ? looks like we'll have to remove the water control panel to investigate for leaks behind it as what we can touch behind the panel seems to be dry. we did remove the peg board concealing the tanks on the curb side of the coach, since it was wet at the bottom, and the top of the water tank & bottoms of grey and black tanks look to be dry, and dusty.

we have reached out to a locally recommended maintenance fella, but it may take a few days for him to arrive. at least we have the leak controlled if we depressurize the plumbing system when not needed. thoughts ? thanks, jeffrey !


Thursday 7th of June 2018

Hi Jeffrey & Kim. Always great to hear from fellow Newmar owners. We're sorry to hear what you're going through. Water leaks, whether from outside or from the plumbing system can be really challenging... and damaging. We have had three total experiences with leaks, one of which equates to yours. The other two are the ones we've featured in videos, and not the same problem your having. The first was a drainpipe leak, featured here, again not your issue. The second was the leak in this post. But that was an internal leak within the valve, which was allowing water through even when it was closed. Obviously, your issue is more serious in that it's allowing water to leak out of the system into the RV.

So... that third leak we've dealt with is more like yours. We didn't do a video about it because it was such a challenge to deal with it that we simply could not be distracted rolling cameras. It went like this... We were working on something under the refrigerator on a project completely unrelated to plumbing. We had the mesh cover off that hides the area under the fridge, and happened to notice a VERY small amount of water on the floor in there. Of course there shouldn't be ANY water... so we investigated. Since there was so little, and the area is on the wet wall in the shower, it was easy to see that it was coming from the shower. We couldn't tell if it was the plumbing or the drain yet, but we knew it was the shower. A look under the shower floor (through the round vent hole below it) revealed bone dry conditions.... dusty dry. So not likely the drain or the seals around the shower door.

We removed the silicone sealant around the shower control, and removed the control so that we could see the hot and cold plumbing connections in the shower wall. Here's where we discovered a very disturbing reality. The gray plastic fittings that connected the PEX to the shower control were in obvious decay. It's as if the plastic had been slowly breaking down over the years, simply eroding away. Sure enough, one of those gray fittings had decayed just enough to finally allow a pinhole of water to seep out. It was surely on the verge of becoming a really serious issue, and we were incredibly lucky to have spotted it by chance in its infancy.

We replaced the plastic fittings with brass ones and have had no problem since. Maybe it was just a defective batch of plastic fittings? Who knows.

Not that this is your problem, but it does give you an idea that the most likely point of failure in the system is the fittings/connection points. PEX is extremely robust. The only way we can imagine a failure of an actual PEX tube is through abrasion over time. More likely, you have a single bad fitting/connector/elbow somewhere. We say "single" because the odds are that it's less likely that you happened to spring two leaks at the same time... although possible of course.

Here's what we'd do.... you have to sleuth out the source of the leak, obviously. Look for the wettest area. The carpet has almost certainly wicked water all over the place, making it hard to find the source. If you've had the water off long enough now for the carpet to dry out, that can help you find the source (if not, let it dry, maybe with the help of a fan or two, which will also stop mold from growing, too). Once its dry, turn the pump back on (using the pump instead of city water will let you confirm how fast water's leaking by listening for the frequency of the pump cycling). If it's cycling faster that it was before, your leak is getting worse. That could be a blessing in disguise, since that might help you locate it faster. Based on one cycle every 20 seconds, you already have a pretty substantial leak.

Once things are as dry as possible, a keen eye kept on the situation (before the water gets wicked all over the place again) can help you pinpoint where the wet is starting from. You need to home in on it. Use a flashlight and a borescope to look into as many crevices as you can (or use other methods of seeing into hidden spaces that we outlined here). Trace along the plumbing lines. Remove panels as needed/possible to follow the lines. Once things are dry down there overall, ANY new water will help lead you to the source of the leak.

Hopefully you can not only find it, but access it. Those are the two challenges of course, in that order. If you can sleuth out where it's coming from, and it's accessible, the third step... the repair... is the easy part, as long as you can get to it. Best of luck, and please let us know how you make out.

Allan Kirch

Wednesday 1st of November 2017

Hi Guys,

As always this is another great video! I would like to know what tools you have in your assortment of tools. In the Favorite RV Gear page, there is a "Tools" link. Besides the usual assortment of wrenches, sockets, screwdrivers, do these tools represent the additional tools you carry? Also in the page there is a Locking Oil Filter pliers. Have you ever considered a strap wrench? They fit a very wide range of diameters. Good for taking off oil filters, water filters, pipes or anything round. The best kind to buy is the nylon strap type because of the strength of the nylon. However sometimes the nylon can slip. I went to my local bike store and got a discarded bicycle inner tube, cut off a small section and threaded the nylon strap through it. The rubber has provided a sticky grip on slippery items. Here's a link to a typical strap wrench:


Wednesday 1st of November 2017

Hi Allan! Thanks for the nice note. We do have a lot of miscellaneous tools that see a lot less use, so most of the more obscure ones haven't make it onto our favorite gear page yet. We do have two strap wrenches (large & small), similar to the type you mentioned, except they're rubber instead of nylon. They're still very strong, and they work great for anything other than the most extreme situation. The only time the large one failed to do the job was removing our air dryer, which was stuck on like a rock! They're similar to this one: We don't use the large one very often (we have a dedicated oil filter wrench for that purpose), and we keep the smaller one in the kitchen for opening jars. ;-)

This site uses Akismet to reduce spam. Learn how your comment data is processed.

PLEASE NOTE: We're handy RVers, not professional technicians. We're happy with the techniques and products we use, but be sure to confirm that all methods and materials you use are compatible with your equipment and abilities. Regardless of what we recommend, consult a professional if you're unsure about working on your RV. Any task you perform or product you purchase based on any information we provide is strictly at your own risk.

We participate in affiliate programs from many companies (including the Amazon affiliate program), which provides a means for us to earn a small commission by linking to products there. But our opinions are our own and we only link to products we can recommend to friends with complete confidence. And using our links won't cost you an extra penny!