Why Is My Toilet Slow to Fill?

Is your toilet tank filling more slowly than usual? This is a known toilet predicament with multiple possible reasons. Thankfully, none of them are major concerns or costly to correct. Follow this guide to get your slow toilet functioning efficiently again. 

How to Repair a Slow-Filling Toilet 

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

Partially Closed Water Supply Valve 

Check behind the toilet for the water supply hose connected to the wall. You’ll see a valve connected to it, which helps you to turn off the water when your toilet is being repaired or replaced. 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 connected to the top of a vertical tube device in the toilet tank, regulates the water level flowing into the tank. A toilet fill valve might break down, clog or shift out of alignment after years of use, stopping the tank from filling appropriately. Follow these tips to adjust, unclog or fix the fill valve: 

  • Locate the fill valve: Remove the toilet tank lid and find the fill valve inside. It’s normally installed 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: Check that the fill valve is secure and evenly fastened to the tube. Change the fill valve height if needed by turning the adjustment knob (found in newer toilets) or find a flathead screwdriver and loosen the adjustment screw (required for older toilets). Next, check that the water level is about one inch below the top of the overflow tube. 
  • Clear debris from the fill valve: To eliminate mineral buildup and other sludge from the valve, first shut off the water in the rear of the toilet and take off the fill cap. After that, slowly turn the water back on, cupping your hand over the valve to keep from being sprayed. Let the water flow for 15-20 seconds to flush out debris. Next, scrub away mineral buildup on the fill cap. If you notice cracks or substantial wear and tear, replace the valve. 
  • Clean the valve tube: Dirt inside the valve tube could also be to blame. Shut off the water supply and take off the valve hardware. Then, run a slim wire or bottle brush down the tube. Turn back on the water supply slightly to rinse away the leftover residue. Re-install the valve hardware and verify if the toilet fills quicker. 

Waterlogged Float Ball 

The float ball in older toilet models rises with the water level, closing the fill valve when the tank has filled. If the float ball is filled with water, it prevents the tank from filling correctly. 

Take off the tank lid and peek inside. A partially submerged float ball might be waterlogged. Before you replace the ball, look at the float arm it’s attached to. If the arm is fixed too low in the tank, bend it up somewhat to lift the ball’s height. 

If that fails to solve the issue, 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 remember that this is an older toilet design, so it might possibly be better to update the existing tank hardware or switch out the toilet completely. 

Clogged Plumbing Vent 

Your home plumbing system uses vents that enable air to enter the pipes. If they are clogged, pressure may build inside of the pipes, preventing the water from flowing. This can, in turn, make your toilet fill at a snail’s pace or even cause the bowl to overrun. 

You need to get on the roof to search for clogged plumbing vents. Search for long, vertical PVC pipes poking up from the tiles. Get rid of any animal nests, deep snow or other obstructions you notice to help your plumbing work as intended. 

Leaky or Blocked Pipe 

If there’s nothing apparently 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 problem with the water line itself could prevent your toilet tank from filling properly. It’s best to hire a licensed plumber to handle these issues. 

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

If these tips did not handle your issue, look to Service Experts Heating, Air Conditioning & Plumbing for reliable toilet repair in the U.S.. We can figure out the reason why this is happening and perform a cost-effective repair. If the fixture has hit the end of its average life span, our specialists can recommend high-efficiency toilet replacement in the U.S.. We’ll help you find the replacement model and install it on your behalf. Rest assured that every job we complete is protected by a 100% satisfaction guarantee! To schedule a visit from us, please contact Service Experts Heating, Air Conditioning & Plumbing today. 

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