Floatless Valve Gotcha!

It took me a bit of time to figure this thing out.. so maybe this post will save someone else the trouble.

Typical floatless valve. There are many brands, all work and look exactly the same

Floatless fill valves are excellent for farm use. Originally designed for the tank of a toilet, these things are extremely accurate on water level, and operate with no externally moving parts inside the water tank.  There are, however, a few gotchas!

1. always install near the bottom of the tank, the max water level allowed is about 2 feet. If you need water deeper than that, just move the valve higher up the side of the tank.

2. Use a standard toilet tank water connector to connect hte supply. This will adapt the weird 5/8 inch thing on the bottom to standard male pipe threads. You can then use 1/2 inch nipple and  1/2" npt to water hose adapter.  Simple and dependable.

3. Be sure to install this right!  That is the part that took a while to figure out. This valve work on differential pressure.. it compares the pressure of the water level inside the tank to the air pressure outside the tank. To accomplish this, it MUST be installed exactly as shown.

The valve installes with the top part inside the tank, threads sticking out. It is VERY IMPORTANT to put the black rubber washer INSIDE the tank. It will not work if this washer is outside.  Also, it must be oriented THIS WAY with the wide edge next to the valve.  Do not turn it around, it wont work. 

On the outside of the tank, use ONLY this weird looking washer, and nothing else. See the little hole at the top? This hole is what makes all the magic work. Plug this hole, and nothing! So make sure that this side is the side facing the wall of the tank.  If you turn this washer/nut around the other way and attach, it will RARELY work.  There are tiny grooves in the side of the valve, above the threads, that allow the outside air pressure to leak past this nut into the inside of the valve without letting water out.  This is how the unit senses outside air pressure. 

This is the OUTSIDE of the nut that holds  the valve in place. (the other side of the above pic). This side, with all the little compartments, must face away from the wall of the tank. Turn it around and you will go nuts trying to adjust the level. 

That's it! Installed right, these little jewels can provide years of faithful service, out of reach of animals and whatever is inside the tank. The level is kept constant and it just works!