Why Is My Toilet Slow to Fill?

Have you noticed that your toilet is taking longer to refill after flushing? This is a known toilet predicament with numerous possible reasons. Fortunately, none of them are major concerns or costly to address. Follow this guide to get your slow toilet flowing properly again. 

How to Address a Slow-Filling Toilet 

Finding out why your toilet is slow to refill is the first step toward fixing it. Consider these possible reasons and the best way to handle each one. 

Partially Closed Water Supply Valve 

Look behind the toilet for the water supply line connected to the wall. You’ll see a valve connecting to it, which allows you to close off the water when repairs or full replacement of the tank is needed. Make sure this value is open by turning it to the left. 

Issues with the Fill Valve or Tube 

The fill valve, which can be found attached to the top of a vertical tube-shaped part in the toilet tank, regulates the water flow into the tank. A toilet fill valve might wear out, clog or slip out of alignment after years of use, stopping the tank from filling right. Follow these instructions to adjust, clear out or fix the fill valve: 

  • Locate the fill valve: Lift the toilet tank lid and find the fill valve inside. It’s normally mounted on the left side with a tailpiece extending through the bottom of the tank and attaching to the supply tube and shut-off valve. 
  • Adjust the fill valve: Make sure the fill valve is secure and evenly attached to the tube. Adjust the fill valve height if needed by twisting the adjustment knob (typical to newer toilets) or use a flathead screwdriver to loosen and adjust (required for older toilets). Then, make sure the water level is approximately one inch below the top of the overflow tube. 
  • Clean the fill valve: To take out mineral buildup and other sludge from the valve, first shut off the water in the back of the toilet and remove the fill cap. Then, slowly turn the water back on, cupping your hand over the valve to keep from being sprayed. Let some water flow for a few seconds to flush out the buildup. Next, scrub away mineral buildup from the fill cap. If you notice cracks or excessive wear and tear, replace the valve. 
  • Clean the valve tube: Debris inside the valve tube could also be at fault. Shut off the water supply and remove the valve hardware. Next, run a thin wire or bottle brush down the tube. Turn back on the water supply slightly to clean away the excess residue. Re-install the valve hardware and check if the toilet fills faster now. 

Waterlogged Float Ball 

The float ball in older toilet models rises with the water level, shutting the fill valve once the tank has filled. If the float ball is damaged or punctured and fills with water, it keeps the tank from filling efficiently. 

Remove the tank lid and peek inside. A partially submerged float ball could be waterlogged. Before you replace the ball, check the float arm it’s secured to. If the arm is directed too low in the tank, bend it up slightly to raise the ball’s height. 

If that does not do the trick, you might want to simply buy a new float ball; the average cost of this product ranges between $7-$20 in most hardware or home improvement stores. Just be aware that this is an older toilet design, so it may be better to update the existing tank hardware or switch out the toilet entirely. 

Clogged Plumbing Vent 

Your home plumbing system features vents that enable air to enter the pipes. If they are clogged, tension may build throughout the pipes, stopping the water from flowing. This can, in turn, make your toilet slow to fill or even cause the bowl to overrun. 

You should grab a ladder and climb up on the roof to check for clogged plumbing vents. Start looking for long, vertical PVC pipes poking up from the shingles. Clear away any animal nests, deep snow or other obstructions you find to help your plumbing work as intended. 

Leaky or Blocked Pipe 

If nothing is wrong with the water supply valve, fill valve and tube, float ball or plumbing vents, the slow toilet dilemma could stem from your supply pipes. A water line leak could restrict your toilet tank from filling properly. It’s a good idea to hire a licensed plumber to handle these issues. 

Schedule Toilet Repair with Service Experts Heating, Air Conditioning & Plumbing 

Is your toilet still not working right? Turn to Service Experts Heating, Air Conditioning & Plumbing for dependable toilet repair in the U.S.. We can figure out the reason why this is happening and perform the most appropriate repair. If the fixture has reached the end of its useful life span, our team can propose high-efficiency toilet replacement in the U.S.. We’ll help you find the replacement model and install it for you. Relax knowing that every job we execute is supported by a 100% satisfaction guarantee! To schedule a visit from us, please contact Service Experts Heating, Air Conditioning & Plumbing today. 

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