I've already mentioned the failings of cheap inline garden hose regulators HERE. After a high water pressure scare, I decided to rethink my water feed and system controls a bit hoping to discover something better and safer. This article covers what I did and hopefully a few folks out there find the information contained herein helpful.

My "tower" of controls. An outlet for tinkering or perhaps something useful.

For those that have the Intellitec system you have multiple "water pump" on/off buttons located near all sinks and the shower. If you are primarily using city water service this button seldom gets used except for the occasional RV park water outage. With a few simple components you can put this button to better usage and make a more versatile system that provides safer water control.

Water mode control switch installed for easy access.

The goal here is to use the "water pump" button as a general water ON/OFF control regardless of where you are getting your water from (city or local pump). A switch (like the one shown above) allows you to easily direct the "water pump" button's function to control the local pump (default) or a solenoid shut off valve (added function).

In my situation the switch remains mostly in "city" mode. I've wired my relay so the normally closed contacts direct the 12 volt feed coming from the Intellitec system to the solenoid valve. In "city" mode when the "water pump" button is ON the solenoid valve opens and supplies water. When you are done using water and/or leaving the vehicle simply press the "water pump" button to close the solenoid valve and shut off the water supply. This prevents a potentially damaging flood that might come from an unattended fully pressurized plumbing system rupture. It's expected if you are around you might see (or hear) a water leak and take corrective action immediately thus reducing the severity of any damage that might occur. A water shut off control doesn't remove the risk of a plumbing failure, it simply allows a plumbing system to be depressurized when it can't be attended. No pressure means no out of control leaks when you're away or sleeping at night.

If a plumbing system's failure can be correlated to the number of hours it remains under pressure, then pressurizing it only as required means a longer elapse time before a failure occurs. Why have a system at full pressure if it isn't going to be required to produce any water??

After a high pressure scare and a busted outdoor fitting (which resulted in an ice rink being created) we figured a shut off valve was a must. It also brings one peace of mind during outings and overnights. We've gotten into the habit of always turning the water off when it isn't needed. With just a push of a button it's very easy to do and shortly becomes second nature. One never knows when a hose is going to let go and most likely it will let go when you are out for an extended time. Murphy was a genius. Faucet feeder hoses and washer hoses are known trouble spots.

If you've done my pressure gauge project, an added bit of information can be gotten about the integrity of your plumbing system. On a perfectly tight system, water pressure will maintain itself after the main shut off valve is closed. If your pressure gauge begins to "bleed" down after you shut the water off then a leak is present somewhere in your system. That might be as innocent as a dripping faucet or as dangerous as a hose dripping before it lets go completely. A convenient water pressure gauge and easy shut off mean you'll check things often. If you can avoid one bad gusher that would do thousands of dollars of damage it's well worth the small amount of extra effort.

Normal closed solenoid valve and regulator combination installed at the city water stand pipe.

Inline garden hose regulators are subject to failures. When they go, full city water pressure may pass through to your plumbing system which could greatly exceed its rating of 45 PSI. Use a simple screw on pressure gauge to check your water pressure.

A simple gauge can be used to check that your regulator is working properly.

Hoses and fittings are subject to the corrosive effects of water. Dissimilar metals in the presence of water containing minerals creates an effect known as galvanic action. This eats away the metals and will cause catastrophic failure in some pipe and hose fittings.

A suspicious hot water hose fitting.

This one let go. Luckily it was outside. Got ice rink!

The control circuit is stupidly simple. You'll install a SPST switch in a convenient spot and run one wire from it into your plumbing bay. That controls the coil (on/off) of a SPDT relay. The relay sends the Intellitec "water pump" feed wire to either the water pump or solenoid valve. The toggle switch controls which mode the "water pump" button will be in.

Ice cube relay with 12VDC coil in plumbing bay. An easy hookup.

Make sure to fuse everything per proper electrical safety rules. I always fuse every battery feed at 7" or less from the source. Make sure fuses are sized just enough to handle the load but blow quickly if a short develops anywhere along wire runs. Size all wiring to handle the required amperage of the loads they will be feeding. I usually run 12ga stranded copper wire for anything around 10 amps or less. This is very conservative. See circuit diagram below:

Suggested circuit diagram for water mode control. It's just one approach.
BIG photo of circuit diagram HERE.

Complete slide show with captions HERE.

If you have an ice maker you'll need to consider that when shutting off your water. After looking at how Norcold ran its water hose into the freezer box, I disabled the ice maker immediately. A 5 Lb bag of ice lasts us 2 weeks and it tastes better. Hope a few find this interesting and helpful. Stay dry and safe out there.
Evolve and simplify!
Scott Bridgman, Why not join and post your own comments??
scott@muniac.com (email me)