Automatic Water Shutoff Valve

[Seangie]

Hey all -

I have been searching to see if anyone has used a solenoid to automatically turn off the water supply when the fresh water tank is full. I have not found anything in the archives so I figured I'd propose an idea here and see what you guys have come up with.

I am thinking that I could use a water solenoid to control the on/off flow of water to the fresh water tank when hooked up to city water.  I will have one manual on/off valve on the cold water manifold to fill the fresh water tank and in line with that would be a solenoid that will automatically turn off when the tank is full. 

Trying to think through what I would use for a trigger.  Different ways to do this using either an NO or NC solenoid. With an NC solenoid I'm thinking that I'd like to have a manual switch inside the coach that would "open" the solenoid by turning the switch on and applying voltage but I can't think of an easy way to automatically remove the voltage once the tank is full.  Maybe some kind of water sensor in the tank that opens the circuit when it gets wet.

I know some of the newer coaches have systems like this and I am sure its nothing ground breaking.  I was just wondering if any of you had built anything and how well it worked before I try to reinvent the wheel.

Thanks.

-Sean

[Brassman]

A place to research a float switch:  http://www.gemssensors.com/Products/Level/Single-Point-Level-Switches/Float .

[Melbo]

I think Scott Bennett was trying to figure this out a spell back

I don't know if he did or not but you might check with him and see.

HTH

Melbo

[06 Bill]

A pressure switch out of a automatic washing machine.    06 Bill

[luvrbus]

Mine is a Aquatec Valve tied to a pressure switch you can either have it automatic or manual control kinda of waste IMO I am always using CLR to remove the deposits caused by the water to keep it working  

 The way it works is it has air release valve(Watts) on the tank to expel the air while filling when the water hits the valve it closes and builds pressure turning on the pressure switch then closing the valve then it by passes the tank and goes to the city water supply  

More trouble than it's worth keep it simple use over flow tubes on the tank and turn the water off when it is full

[Ed Hackenbruch]

Mine is setup so that i can hook up a hose to a quick dis-connect fitting and have water all of the time without filling the tank or running the pump.....i never use it because i do not want to take the chance of a leak or broken pipe flooding the bus while i am gone somewhere during the day.  What i do is hook up to the other quick dis-connect fitting and fill my tank and then shut the hose off. I then use my pump to supply water as needed. If i am going to be away from the bus for a day or longer i just flip a switch to turn off the power to the pump. We can go a week on 100 gallons of water if needed, but i just usually fill the water tank and dump the black tank every 3-4 days.  In 9 years of fulltiming we have had 3 leaks,.... ( it is not a question of IF you will have a leak, just a question of WHEN you will have a leak and how much of a mess it will make! ). Twice it was the old ice maker which is no longer with us. The other time it was a fitting in one of the bays that cracked. Luckily i found all 3 leaks before they got bad,(one was in the middle of the night,   heard the pump cycling), doing it my way the most water that i would have lost would have been 100 gallons if the tank was completely full at the time. Using the other part of the system and developing a leak could result in many hundreds or even thousands of gallons of water lost into the bus if i was not there at the time.  Don't know how old the pump was when we got the bus but i did have to replace it a couple of years ago. All in all, a pretty fool-proof and easy system....no floats, switches, relays, etc. to worry about.

[zubzub]

fwiw commercial espresso machines have a very nice valve that runs on 120 that does just that..... uses a couple of rods in the water to sense level to turn on and off.  Have this on my espresso machine, works flawlessly, would  work in other applications.

[Seangie]

So this project has been stuck in my head for a while and I had to put it down on "paper" to get it all out.

Special thanks to Scott Bennett for inspiring this (without the inspiration I might have had a good nights sleep )

A place to research a float switch:  http://www.gemssensors.com/Products/Level/Single-Point-Level-Switches/Float .

Also thanks to Brassman for turning me on to the single point level float switches

Attached is the drawing that I came up with.  The overall objective is to keep this really simple. 

I am always using CLR to remove the deposits caused by the water to keep it working

Cliff - I think you make a good point about the solenoid clogging up from the deposits and not working correctly.  I have 2 filters inline that will hopefully help reduce this problem. 

The basic operation is turning on the switch inside the coach which closes the autofill circuit.  The float valve is NC (Normally Closed) so that when the tank is less than full the circuit is powered and causes the solenoid to open and fill up the tank.  When the tank is full the float valve then opens the circuit and turns off the solenoid. 

Some additions that I would like to add to this are -
1. A light that comes on in the coach when the tank is full (could probably use tank indicator lights but a simple light indicating that the autofill circuit is open is what I am thinking here)
2. A moisture/spill indicator in the overflow tube that powers a circuit with an alarm to let you know that water is flowing through the overflow tubes.

Because my coach is 12v I will keep all things electrical 12v as well.  You could changes the parts/pieces to fit your coach.

I think I could pull this off for less than 100$.   I have seen 1/2"  12v solenoids for less than 30$ on amazon.  The single point valve fromt he gems website is $35 or so and I am sure that I could find one cheaper.  The relay and switch would be about 10-12 bucks and the wire would cost about 20$ unless I have some lying around somewhere.

I have a 3/4" FPT opening and a 1.5" FPT opening on the top of my freshwater tank.  My Idea is to have the 1/2" pex line feed into the 1.5" opening  along with the connection to stick a hose in to fill up as well.  The 3/4" opening would be where I would screw in the float switch.  They look pretty small on paper and I think I would have no problem fabricating something that would just screw into the top of the tank.

This project is a ways off for us but when I get to it I will post my success failures on our website and here as well. 

If anyone else wants to get a head start on me take lots of pics and let us know how you do.

-Sean
www.herdofturtles.org

[bobofthenorth]

K.I.S.S.

Every stock watering trough in the country has a dead simple mechanical float that shuts off the water when the trough gets full.  Go to Tractor Supply - I'll bet they're less than $10 per each.  And did I mention - they're dead simple.

[gus]

My tank has a simpler solution, water just runs out the top vent!

[Ed Hackenbruch]

Sean, your idea of "really simple" is a lot different than mine!

[belfert]

I believe Scott didn't want water running out and making a muddy spot around the bus. 

[luvrbus]

Sad part he still needs to go outside to disconnect and turn the hose off then roll it up

[bobofthenorth]

My tank has a simpler solution, water just runs out the top vent!

That's the way mine works too Gus.  If its a quiet day & I take the time to stand there and listen carefully I can hear it start to gurgle when it gets close to overflowing.  But generally I lose interest, go off to some other project and come back in a while to find a puddle.  I know its been full for a while when my feet get wet. 

[Seangie]

Sad part he still needs to go outside to disconnect and turn the hose off then roll it up

Cliff - still working on the automatic hose disconnect and rollup machine.  

www.herdofturtles.org
1984 Eagle Model 10S