Why Is My Toilet Slow to Fill?

Is your toilet tank filling more slowly than usual? This is a common toilet problem with numerous possible culprits. Luckily, none of them are major concerns or costly to correct. Follow this guide to get your slow toilet functioning properly again. 

How to Address 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 

Look behind the toilet for the water supply line attached to the wall. You’ll notice a valve connected to it, which helps you to shut off the water when repairs or full replacement of the tank is needed. Examine the value to ensure it is fully open. 

Trouble with the Fill Valve or Tube 

The fill valve, which can be found attached to the top of a vertical tube device in the toilet tank, controls the flow of water into the tank. A toilet fill valve may break down, clog or reposition out of alignment after years of use, stopping the tank from filling right. Follow these tips to adjust, clean or fix the fill valve: 

  • Locate the fill valve: Remove the toilet tank lid and find the fill valve inside. It’s usually mounted on the left side with a tailpiece extending through the bottom of the tank and connecting to the supply tube and shut-off valve. 
  • Adjust the fill valve: Be sure that the fill valve is secure and evenly fastened to the tube. Adjust the fill valve height if necessary by twisting the adjustment knob (found in newer toilets) or find a flathead screwdriver and loosen the adjustment screw (required for older toilets). After that, 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 dirt from the valve, first shut off the water in the back of the toilet and take off the fill cap. Then, slowly turn the water back on, cupping your hand over the valve to prevent from being sprayed by the water. Let the water flow for several seconds to flush out the buildup. Next, scrub away mineral buildup off the fill cap. If you notice cracks or significant wear and tear, replace the valve. 
  • Clean the valve tube: Debris lodged in the valve tube could also be at fault. Turn off the water supply and remove the valve hardware. Next, run a thin wire or bottle brush down the tube. Start the water supply slightly to flush away the leftover residue. Replace the valve hardware and verify 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 whenever the tank is full. If the float ball is damaged or punctured and fills with water, it prevents the tank from filling correctly. 

Pull up the tank lid and peek inside. A partially sunken float ball might be waterlogged. Before running out to buy a new ball, check the float arm it’s connected to. If the arm is pointed too low in the tank, bend it up a little bit to lift the ball’s height. 

If this doesn’t work, then it might be time to just replace the component entirely. Just be aware that this is old toilet technology, so it may be better to upgrade the existing tank components or switch out the toilet completely. 

Plugged Plumbing Vent 

Your home plumbing system uses vents that allow air to enter the pipes. If they end up clogged, tension may build throughout the pipes, stopping 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 look for clogged plumbing vents. Look for long, vertical PVC pipes poking up from the roof tiles. Get rid of any animal nests, deep snow or other obstructions you see 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 issue could stem from your supply pipes. A leak or blockage in the water line could restrict your toilet tank from filling appropriately. It’s best to hire a licensed plumber to fix 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 reliable toilet repair in the U.S.. We can identify the reason why this is happening and perform the most appropriate repair. If the fixture has hit the end of its average life span, our company can suggest 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 perform 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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