How To Flush Your Toilet When Water Is Off. Open any of the faucets in the house to completely drain the pipes. Collect the water in a large bucket that you will be able to lift and pour.
You want the water to be clean (no debris) but it doesn’t have to be drinkable water since it’s going down the toilet anyway. Make a slight upward bend in the arm of the float ball. One reassuring part of using the bucket method is that it doesn't matter what water you use since it's all going down the toilet anyway.
Take some water and fill the tank with approximately 3/4 of a gallon.
Collect the water in a large bucket that you will be able to lift and pour. Use a bucket of water (or two) to flush the toilet. With about a gallon of water, poured in the bowl slowly at first then more rapidly near the end, you can force any matter down the toilet without having to even pull the handle down. In order to understand how to get your toilet to flush without a connection to your main water supply, we'll first have to look at how a toilet functions.