Why Is My Toilet Slow to Fill?

Is your toilet tank filling more slowly than usual? This is a frequent toilet problem with multiple possible reasons. Fortunately, none of them are major concerns or costly to address. Follow this guide to get your slow toilet functioning properly again. 

How to Fix a Slow-Filling Toilet 

Finding out why your toilet is slow to fill is your first step toward fixing it. Think about these possible reasons and how to handle each one. 

Partially Closed Water Supply Valve 

Check behind the toilet for the water supply line attached to the wall. You’ll find a valve connecting to it, which allows you to close off the water when your toilet is being repaired or replaced. Make sure this value is open by turning it to the left. 

Problems with the Fill Valve or Tube 

The fill valve, which can be found close to the top of a vertical tube device in the toilet tank, regulates the flow of water 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 tips to adjust, clean or fix the fill valve: 

  • Search for the fill valve: Remove 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 connecting to the supply tube and shut-off valve. 
  • Adjust the fill valve: Be sure that the fill valve is secure and evenly connected to the tube. Modify the fill valve height if necessary by twisting the adjustment knob (found in newer toilets) or loosening the adjustment screw with a flathead screwdriver (required for older toilets). After that, check that the water level is about one inch below the top of the overflow tube. 
  • Clean the fill valve: To take out mineral buildup and other dirt from the valve, first shut off the water in the back of the toilet and remove 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 the buildup. Next, scrub away mineral buildup on the fill cap. If you observe cracks or substantial wear and tear, replace the valve. 
  • Clean the valve tube: Dirt lodged in the valve tube could also be to blame. Shut off the water supply and take out the valve hardware. Afterward, run a thin wire or bottle brush into the tube. Turn back on the water supply slightly to rinse away the excess residue. Reconnect the valve hardware and check if the toilet fills quicker. 

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 filled with water, it prevents the tank from filling correctly. 

Remove the tank lid and peek inside. A partially sunken float ball may 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 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. But it’s worth remembering that this is an older toilet design, so it may be better to modernize the existing tank components or replace the toilet entirely. 

Plugged Plumbing Vent 

Your home plumbing system features vents that permit air to enter the pipes. If they become clogged, stress may build inside of the pipes, blocking the water from flowing. This can, in turn, make your toilet fill at a snail’s pace or even cause the bowl to overflow. 

You need to get on the roof to look for clogged plumbing vents. Search for long, vertical PVC pipes poking up from the shingles. Do away with any animal nests, deep snow or other obstructions you see 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 issue could stem from your supply pipes. A problem with the water line itself could restrict your toilet tank from filling appropriately. It’s safest 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 quality toilet repair in the U.S.. We can pinpoint the reason why this is happening and perform a cost-effective repair. If the fixture has hit the end of its useful life span, our team can recommend high-efficiency toilet replacement in the U.S.. We’ll help you find the replacement model and install it on your behalf. You can relax knowing that every job we complete is backed by a 100% satisfaction guarantee! To schedule a visit from us, please call Service Experts Heating, Air Conditioning & Plumbing today.