Water supply plumbing in RV's

How reliable is the plastic plumbing used for water supply lines in RV's?  I've seen connectors with crimped ferrules and threaded compression type connectors.  Given the damage (lotsa $$$) that a leaky connection can cause, and the adverse conditions to which connections are subjected (vibration, wide temperature swings, varying supply pressures, etc.), is there a better solution than the plastic lines and fittings?  What about sweated copper lines and fittings, such as are used in non-mobile houses?

I'm asking this question since my son's house is plumbed with crimped ferrule type plastic supply lines, and there is a huge class-action suit being brought by homeowners whose homes have experienced major damage from leaking water supply lines of this material.  My concern is, if a stationary home plumbed with this stuff is at risk of damage, what about an RV, where the conditions are much more severe?

John in SW Ohio

John,

My MH is a '96 with crimped joints and plastic pipe, and haven't had any problems. Like any other piping, freezing and bursting can be a problem, but with proper care it shouldn't be. Retrofitting with copper would be a costly, if not impossible task, due to the majority of the plumbing running beneath, inside, next to floors and walls. Not worth the cost and effort IMHO. As you mentioned, supply pressures can vary all over the place, and most of us have installed whole-house pressure regulators. Those little ones you can buy at various camping/rv stores for $5-$10 are just too restrictive to be of any use.

It doesn't seem to be a problem. I won't claim that no one ever had an Rv water  fitting leak - far from it - but the incidence of problems is small, even without considering the rigors of travel.

I have the same sort of fittings in my home water supply system - it is 36 years old now and there has never once been a leak at a crimped connector or a failed flex line.  Not all types and brands of flex fittings are failure prone.

I've serviced a few RV's and the most common problems were with the toilet leaking. The actual plumbing seems to stand up well, however we shut our water pump off whenever we leave the rig. Paranoid because we had a friend who left for a few hours, there was a leak, and his rig was flooded. Unusual though....only one I know of. Keep in mind that the older gray pipes are no longer used in Rv's and they have gone to the "white." Reason was for health standards.

RV plumbing is designed to take 45 psi of pressure.  I have been in campsites where the pressure went upwards towards 100 psi (Salt Lake City).  Always use a 45 psi pressure regulator.  It is also an excellent idea to turn off the water at the hose bib if you are leaving for the day.

What are these whole-house pressure regulators and where do you get them? What do you mean the small RV ones are too restrictive?

I actually was wondering about the plumbing question raised above as well conerning specifically the polybutylene product.  My Pace Arrow has the grey polybutylene plumbing throughout and the copper fitted joints with the crimp ring style fitting.  This product was used in houses built from the 70' through around 1995 or so until Shell got their pant sued off.  Some of this product was part of a class action lawsuit (household plumbing that is) but not all of the grey polybutylene.  I had both my yard supply line (which was a blue color but definitely PB) and interior plumbing fail within 3 weeks of each other when the house was 7 years old!  Many of my neighbors that had similar houses of the same vintage and builder had the same problems at nearly equal intervals.  I had the house and yard replumbed as part of the class action suit in 2001.  My reading on the subject has revealed that there are a couple of things that make the situation better such as copper joints instead of plastic joints, lower chlorine levels in the water and of course age of the product.  It doesn't sound like this is a widespread problem in MH's which I am glad to hear!  However, when it failed in my house it was a mess at mine failed in the crawl space.  I would guess that if one has pex or cPVC then the plastic is not any more of a concern than anything else in the MH failing, but I am keeping a watchful eye on the grey polybutylene and definitely will be turning off the hose bib or water pump when I am out of the rig for more than a short period.

davidsimmonds said:

What are these whole-house pressure regulators and where do you get them? What do you mean the small RV ones are too restrictive?

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You can find whole house regulators at most well stocked home improvement stores like Lowes or Home Depot.  Amtek is one major manufacturer, but there are others.

The typical regulator sold for RV, like the Marshall Brass ones, are designed for irrigation systems and the restrict the flow rate significantly.

Carl Lundquist said:

RV plumbing is designed to take 45 psi of pressure.  I have been in campsites where the pressure went upwards towards 100 psi (Salt Lake City).  Always use a 45 psi pressure regulator.  It is also an excellent idea to turn off the water at the hose bib if you are leaving for the day.

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Carl

I believe that the RVIA spec for plumbing is 125 PSI. I know of one water/filter vendor who gives FMCA seminars that says he never uses a pressure regulator, tho his competitors do sell them.

I don't use a regulator until the pressure gets over 80psi and have not had any problems.  I've connected to supplies that showed 100psi before using the regulator, but I shut it off as soon as I read the pressure.

What do you use to read the pressure? Another device available at Home Depot?

I have a pressure gauge that attaches to my water hose on one side and a quick connect fitting on the other that attaches to my water filter.  The gauge is available from most RV stores, but you can also get whole house regulators with attached pressure gauge.  I prefer the separate gauge as I can use it without the regulator.

davidsimmonds said:

What do you use to read the pressure? Another device available at Home Depot?

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Camping World and other RV outlets.? I use an adjustable mobile home regulator to get better volume at 45 psi.? Since the regulator is adjustable I hook up the pressure gauge on the outlet side of the regulator to be able to properly adjust to 45 psi.? ?You can see the examples of one vendor's line by clicking HERE.

The small ones are about 1-1/2" long and look like an anti-siphon device you would place on a hose bib. Yes, they do reduce the pressure, but at the cost of reducing water flow to a great extent. The better ones are true pressure regulators; some with and some without gauges. I prefer those with the gauge so you can regulate the pressure without having to make a seperate reading with a seperate gauge - your choice.

As was said, your MH plumbing system may very well handle pressures up to and including 125 psi, but if and when a leak or rupture happens, I'd rather have it occur at 45 or 50 psi than one at something a lot higher. More time (less water) to correct the problem before serious water damage occurs.   

I keep my big regulator set at 55-58 psi. I like some extra pressure in the shower whenever possible.

I bought a Watts Series 25AUB-Z3 regulator. It's 3/4" fitting size. $60cdn. I had to add a few fittings onto it to put a gauge and the water hose connectors on it. This made it about 12" long and brought the price to about $98cdn. It can be adjusted to 75psi but it is preset to 50psi. The water pressure is much better now compared to using the standard RV store issue so called pressure regulator.

I have tried several pressure regulators and in fact carry a spare

Fair, but flow is too low - Marshall brass

Better (Still good regulaton but better flow) Campoing world's "Hi Volume" one

Best, by far, the type DavidSimmonds uses (Whole house pressure regulator) you should be finding one of these on E-bay soon, the plumbing store had 2 and was getting ready when I walked in the door... Mine is set to 45psi though  I had to add a fitting or 3 as well

Also on the recently aqurired list is a spring loaded check valve (3/4 inch) this will go between the supply hose and the flusher hose when I flush out the tank... Sequence will be supply hose, Cut off valve, check valve, quick disconnect, flusher hose (short hose) and inlet on the MH.  I found out the other day that if a park uses 1/2 inch hose for the Non-Potable Water spigot and cuts the end off (Commonly done) it fits perfectly in the quick disconnect.

If they use 3/4 inch hose, i have an adapter