Why Is My Toilet Slow to Fill?

Is your toilet tank filling more slowly than usual? This is a known toilet issue with several possible reasons. Luckily, none of them are major concerns or expensive to address. Follow this guide to get your slow toilet flowing quickly again. 

How to Repair a Slow-Filling Toilet 

Finding out why your toilet is slow to fill is the first step toward fixing it. Keep in mind these potential reasons and how to deal with each one. 

Partially Closed Water Supply Valve 

Take a peek behind the toilet for the water supply hose attached to the wall. You’ll see a valve connecting to it, which helps you to shut off the water during toilet repairs and replacements. Make sure this value is open by turning it to the left. 

Trouble with the Fill Valve or Tube 

The fill valve, which is connected to the top of a vertical tube device in the toilet tank, controls the water flow into the tank. A toilet fill valve could wear out, clog or shift out of alignment after years of use, stopping the tank from filling properly. Follow these instructions to adjust, clean or fix the fill valve: 

  • Search for the fill valve: Lift the toilet tank lid and find the fill valve inside. It’s usually secured 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. Change the fill valve height if needed by turning the adjustment knob (found in newer toilets) or use a flathead screwdriver to loosen and adjust (required for older toilets). Next, ensure that the water level is roughly one inch below the top of the overflow tube. 
  • Wash the fill valve: To take out mineral buildup and other debris from the valve, first shut off the water in the rear of the toilet and take off the fill cap. Right after that, slowly turn the water back on, cupping your hand over the valve to avoid getting sprayed. Allow the water to flow for 15-20 seconds to flush out the buildup. Next, scrub away mineral buildup on the fill cap. If you detect cracks or excessive wear and tear, replace the valve. 
  • Clean the valve tube: Debris trapped in the valve tube could also be at fault. Turn off the water supply and take out the valve hardware. Afterward, run a slim wire or bottle brush down the tube. Start the water supply slightly to flush away the excess residue. Re-install the valve hardware and confirm if the toilet fills faster now. 

Waterlogged Float Ball 

The float ball in older toilet models rises with the water level, sealing the fill valve whenever the tank is full. If the float ball is filled with water, it keeps the tank from filling correctly. 

Remove the tank lid and peek inside. A partially submerged float ball might be waterlogged. Prior to replacing the ball, look at the float arm it’s attached to. If the arm is fixed too low in the tank, bend it up a little bit to elevate the ball’s height. 

If this doesn’t work, 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 old toilet technology, so it might possibly be better to update the existing tank hardware or change out the toilet completely. 

Clogged Plumbing Vent 

Your home plumbing system includes vents that enable air to enter the pipes. If they end up being clogged, tension may build throughout the pipes, stopping the water from flowing. This can, in turn, make your toilet fill slowly or even cause the bowl to overflow. 

You should grab a ladder and climb up on the roof to search for clogged plumbing vents. Look for long, vertical PVC pipes poking up from the shingles. Clear away any animal nests, deep snow or other obstructions you find to guarantee that your plumbing can function 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 appropriately. It’s a good idea 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 dependable toilet repair in the U.S.. We can pinpoint the reason why the water flow is so slow and perform a budget-friendly repair. If the fixture has come to the end of its typical life span, our team can suggest high-efficiency toilet replacement in the U.S.. We’ll help you decide on the replacement model and install it on your behalf. Relax knowing that every job we perform is backed by a 100% satisfaction guarantee! To schedule a visit from us, please contact Service Experts Heating, Air Conditioning & Plumbing today.