- Check the toilet water supply valve, which is on the wall behind the toilet and supplies the water in the tank for flushing. To locate the valve, follow the water supply pipe or hose connected on the underside or back of the tank until it meets the valve. Ensure that the valve is in the open position by rotating the valve counterclockwise as far as it will go.
- Check the water supply hose for kinks. If the line between the water supply valve and the tank is bent or kinked, water will not be able to reach the tank. Straighten out the hose. Attach the hose to a wall with a clamp to keep it up and out of the way.
- Replace the water supply hose. If debris or rust is blocking the hose, it also won't be able to supply water. To replace, first turn off the water supply valve by rotating it clockwise. Unscrew the metal coupling on the hose from the water supply valve. Unscrew the other end of the hose from the tank. Wrap the threads on both the water supply valve and the tank inlet with Teflon plumber's tape. Reattach the hose to the water supply valve and the tank inlet. Restore the water supply.
- Replace the toilet fill valve. The fill valve connects to the water supply hose and fills the toilet with a supply of water for each flush. To replace, shut off the water supply and disconnect the supply hose. Unscrew the plastic retaining nut on the underside of the tank and lift the fill valve out of the tank. Apply a few dabs of silicone grease to the underside of the washer on the new fill valve and set it in the bottom of the tank. Screw the retaining nut onto the threads at the bottom. Wrap the inlet with plumber's tape and reconnect the hose. Restore the water supply.
Things You Will Need
- Teflon plumber's tape
- Water supply hose
- Fill valve
- Although it's technically possible to repair a fill valve rather than replacing one, older fill valves may no longer be up to code if repaired. New fill valves are inexpensive and more efficient, especially ones with integrated floats.