Chasing down a water leak in 5th wheel

[azcowgirl12]

We have a 2018 GD 220RK 5th wheel that has developed a water leak between the flooring and the first carpeted riser (of the interior steps) that leads up to the bathroom and bedroom. We initially thought that maybe it was a roof vent causing the leak as we had heavy rain while at the RV park, so my husband got up on the roof and put a bead of silicone around the suspected roof vent, but the water leak reappeared sometime during the night (we had no rain through the night) and was discovered when I checked it early the next morning (it’s about a 8” diameter puddle). We had camped in it for 10 days at an RV park in Colorado early July then hauled it to an RV park in northern AZ, and were connected to water both times and we didn’t have the issue when we were in Colorado. When we left CO and drove to AZ, we did hit some rough roads so we are now suspecting that a connection may have come loose. I am wondering if the water line(s) are routed behind the stair riser which might may lead to the bathroom. Has anybody experienced this before? If so, is it a pain in the butt if we attempt to fix this ourselves or are we better off taking it to an RV repair facility?

[Jkwilson]

Sorry to hear you are having problems!

It’s fairly easy to take out the basement wall to get access to that area so you can see what’s going on and make a repair as needed.

For future reference, silicone isn’t a good choice for sealing the roof. There are special sealants and tapes that remain somewhat tacky that handle RV roof duty better.

[Country Campers]

There is a removable wall on the rearward side of the pass thru storage, a few screws on each end, unfortunately you will have to empty this storage area. Behind this you will get access to plenty of the plumbing pipes. I would guess that there is one going up to the bathroom area that may have a leak. This tubing may be soft hose or pex. The pex will be easy to fix, the soft hose you may have to remove it and replace with pex. If you are handy this is not too bad of a job to do, and if you do not mind tight places with very little room to work. This will also provide you with a look at some other items that you may need to access at some time.

Brian

[azcowgirl12]

Thank you both for your response! My husband discovered that the water line going to the toilet was the culprit. It had come loose so he tightened it up and after a day of having it hooked up to water at our home, we have not seen the water puddle anymore. But that brings me to my next question. Should we be using a water pressure regulator? While I was researching our water leak, I have seen a few articles that suggested that we use a pressure regulator as the water systems in RVs are designed for a maximum of 45 PSI, and connecting to city water systems and/or RV park water systems can have a water output greater than what the RV water system is designed for. Sorry for the dumb questions, but this is our first 5th wheel and we are still learning! Thank you in advance!

[Jkwilson]

Thank you both for your response! My husband discovered that the water line going to the toilet was the culprit. It had come loose so he tightened it up and after a day of having it hooked up to water at our home, we have not seen the water puddle anymore. But that brings me to my next question. Should we be using a water pressure regulator? While I was researching our water leak, I have seen a few articles that suggested that we use a pressure regulator as the water systems in RVs are designed for a maximum of 45 PSI, and connecting to city water systems and/or RV park water systems can have a water output greater than what the RV water system is designed for. Sorry for the dumb questions, but this is our first 5th wheel and we are still learning! Thank you in advance!

A regulator is a really good idea.

[Country Campers]

I have always used the camco brass regulator which is about 45 psi. The system in the RV is tested and rated for higher pressures but I do not like to chance this, water leaking is the enemy.

A similar version here Amazon.com: Camco (40055) RV Brass Inline Water Pressure Regulator- Helps Protect RV Plumbing and Hoses from High-Pressure City Water : Automotive

Brian

[Cate&Rob]

An inlet pressure regulator has no control over the maximum water pressure created within the RV plumbing system by the water heater. There are many threads on this topic. See https://gdrvowners.com/forum/operati...water-pressure particularly post #14 for more details. The only time that I would use an inlet pressure regulator (which is a significant flow restriction) would be if my system pressure gauge showed park pressure above 50 psi . . . which would be a rare occurrence. Of course . . . this requires having a system pressure gauge . . . which (as I have said many times before) is the best $15 you can spend on understanding many things about your RV water system.

Rob

[Lonestar]

It looks as if there may be a fair amount of folks not using pressure regulators (or monitoring with a gauge) on the water input of their trailers. I have not seen a reliable source that the trailers are engineered for pressures of 90 - 100 psi, but I'll assume that's correct. I would not want to take a chance on pressures above 50 psi.

I'm just wondering if not all, but some of those reports we are seeing of water leaks at the PEX to braided hose connections may be enhanced by unreasonable high water pressure?

[TedS]

It looks as if there may be a fair amount of folks not using pressure regulators (or monitoring with a gauge) on the water input of their trailers. I have not seen a reliable source that the trailers are engineered for pressures of 90 - 100 psi, but I'll assume that's correct. I would not want to take a chance on pressures above 50 psi.

I'm just wondering if not all, but some of those reports we are seeing of water leaks at the PEX to braided hose connections may be enhanced by unreasonable high water pressure?

Look to the RVIA for the standard for water system pressure design.

[Cate&Rob]

A pressure regulator controls water pressure coming into the RV, but once the water is past the inlet check valve, it is contained within the RV plumbing and beyond the control of the pressure regulator. The same thing happens with the onboard pump. It will supply water until its shut-off pressure is reached, but then the check valve in the pump locks that water in the RV system in the same way.

Heating the water in this closed system beyond the supply check valves, causes the pressure to rise. The air dome in the water heater will absorb some of this expansion and the soft hose will absorb some. Beyond that, the pressure relief valve in the water heater opens. This happens when the system pressure reaches 140 psi.

The static water pressure in an RV system will regularly climb beyond 70 psi. Many on this forum have observed this by installing a system pressure gauge T'd into any cold water line.

Rob