Why Your Toilet Takes So Long to Fill

Read on to find out three common reasons why a toilet fills slowly, how to figure out what’s wrong, and what you can do to fix it.

Here are three reasons why your toilet might take a long time to fill with water:

The knob that sticks out of the wall just below your toilet tank is the water supply valve. It controls how much water flows into your toilet tank. If it’s only partly closed or not working right, it might not let the right amount of water out at the right speed. Another thing that could go wrong with the valve is a buildup of debris, which can slow the rate at which the valve fills.

Check the valve to make sure it’s fully open as a troubleshooting tip. If you open the valve all the way and still don’t get enough water to fill the tank, call a licensed plumber to check the valve for debris buildup.

2. Float Ball Sank

The amount of water going into the tank is controlled by a float ball that sits on top of the water. If the float ball is full of water, it won’t let the tank fill up as quickly as it could. Because of this, it can stop the right amount of water from getting into the tank or cause the water to fill up more slowly than desired.

Tip: Take off the lid of the toilet tank and look at the water level. If the tank is only half full or the ball isn’t floating near the top, the float ball may be full of water. The good news is that it’s easy to change the float ball. Just pull the old one off the float arm and put the new one in its place.

A float ball is an old way of making a toilet work. If this mechanism stops working, you might want to replace it with newer parts.

3. Fill Valve Tube Issues

The fill valve is attached to a device inside the toilet tank that looks like a vertical tube. The fill valve controls how much water is in the tank. Fill valves can wear down, get clogged, or move out of place over time. Any of these problems can make the toilet not fill with water properly.

Tip: If you’ve ruled out the water supply valve or a float ball that’s clogged with water, it’s time to look more closely at the fill valve. Check the valve to see if there are any signs of wear and tear or if it is in the wrong place inside the tank. It should usually be attached to the left side of the tank, with a tailpiece going through the bottom of the tank to connect to the supply tube and shut-off valve.

1. Open the valve that lets water in. The water supply valve might only be partially open sometimes. Make sure the valve is fully open by checking it.

2. Change the filling valve. To change the fill valve, do the following:

• Take off the top of the tank and look for the fill valve, which is usually on the left side of the tank.
• Make sure the fill valve is attached to its tube in a way that is tight and even.
• To let more water into the tank of an older toilet, loosen the adjustment screw with a flathead screwdriver and raise the fill valve.
• To let more water into the tank of a newer toilet, turn the fill valve adjustment knob by hand.
• Make sure the water level in all toilets is about 1 inch below the top of the overflow tube.
• Flush the toilet and then look to see if the tank fills with the right amount of water at the right rate.

3. Wash the Fill Valve. See any gunk or mineral buildup on the valve? Here’s how to get it clean:

• Turn off the water to the toilet and take the tank lid off.
• Take the fill cap off by unscrewing the screws on top of the fill valve.
• Turn the water on slowly while holding your hand over the valve to keep it from getting sprayed.
• Let the water flow freely through the valve. This will flush out any dirt or buildup that has gathered there.
• After letting the water flow for a few seconds, turn off the water.
• To find the washer, turn the fill cap upside down. Take it off with a screwdriver and scrub away any mineral buildup with a soft cloth.
• If you see cracks, you should get a new fill valve.
• Lastly, put the valve back in place, tighten it with the screws, and turn on the water to see if the problem is fixed.

4. Fix or replace a float ball that is full of water

• Check to see if the float ball’s arm is attached too low in the tank. If that’s the case, slightly bend the arm up so the ball rises higher in the tank and lets more water in.
• If this doesn’t work and you still think the float ball is the problem, you may need to install a new float ball or talk to a local plumber about upgrading to a newer style of mechanism and for drain cleaning services.

5. Fix a Valve Tube Problem. To fix a valve tube that is clogged, you must clean out the tube.

• Turn off the water supply to start.
• Take the parts off of the valve.
• To clean out the tube, use a thin wire or a bottle brush.
• Open and close the water supply valve a few times to clear all the clogs and get rid of any leftover debris.
• Replace the hardware and the tube, and check to see if the toilet starts to fill properly after you flush it.

Install a new valve tube if the old one has holes, tears, or looks worn or damaged.