Supplying Water to Toilet from Gravity Feed Tanks

[erness.wild]

ter closet. I'm filling the large tank with water from a sump pump.

er closet doesn't function using the gravity feed supply. However the regul ator works fine when using the city supply for water.

k with very low pressure water supply?

I'm back, just read most of the replies.

What I ended up doing is taking the shut off valve a part (it was easy) and removing the large rubber rings that are used to quiet the water flow. I t hink that's what they're in there for. I left only the small one that actua lly shuts off the water when the ball arm is lifted to the top of the tank by the water height. So the low water pressure works now and I've been using the system all mont h. It takes about six minutes for the toilet tank to fill enough for another f lush. With the large rings removed I can hear the water trickling into the tank, but I don't mind as it lets me know its working okay. Thanks for all the input.

[hrhofmann]

Great to have the final feedback

[nestork]

Ahh, finally. I finally got the proof I needed to show that toilet ballcocks (at least the FluidMaster A400) use the water pressure in the supply line to open and close, and not the buoyancy force of the float, which was a contentious issue in this thread.

Readers are referred to Fluidmaster's own tech support page here

The above PDF file explains exactly how the diaphragm (which they call the "seal") is pushed up and down by water pressure acting on it.

Clare_Snyder: The water valves in clothes and dish washers operate exactly the same way, it's just that they use an electromagnet to pull a plug out of a hole in the diaphragm and a spring to push it back in. But, it's still the _water_pressure_ that pushes the diaphragm off the seat and water pressure that pushes it back onto the seat, not the electromagnet. The electromagnet merely pulls the plug out to release the water pressure on the large area side to cause the valve to open and the spring just pushes that plug back in to cause the valve to close.

[Brad Tuttle]

This is a really old thread but in case someone else views it, Jobe makes a flow valve that works with any water pressure above zero. It is sold on Amazon. I use it for gravity fed water troughs for my goats but it would work great inside a gravity fed toilet.