Why Is My Toilet Slow to Fill?

Is your toilet tank filling more slowly than usual? This is a known toilet predicament with numerous possible reasons. Thankfully, none of them are serious concerns or costly to address. Follow this guide to get your slow toilet flowing quickly again. 

How to Address a Slow-Filling Toilet 

Understanding why your toilet is slow to fill is your first step toward fixing it. Think about these possible reasons and how to deal with each one. 

Partially Closed Water Supply Valve 

Check behind the toilet for the water supply hook-up connected to the wall. You’ll notice a valve connected to it, which enables you to turn off the water during toilet repairs and replacements. 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, manages the flow of water into the tank. A toilet fill valve might degrade, clog or slip out of alignment after years of use, preventing the tank from filling appropriately. Follow these instructions 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 commonly mounted on the left side with a tailpiece extending through the bottom of the tank and linking to the supply tube and shut-off valve. 
  • Adjust the fill valve: Make sure the fill valve is secure and evenly connected to the tube. Modify the fill valve height if necessary by turning the adjustment knob (typical to newer toilets) or loosening the adjustment screw with a flathead screwdriver (required for older toilets). Then, verify that the water level is approximately one inch below the top of the overflow tube. 
  • Clean the fill valve: To eliminate mineral buildup and other sludge from the valve, first shut off the water in the back of the toilet and take off the fill cap. After that, slowly turn the water back on, cupping your hand over the valve to avoid getting sprayed. Let some water flow for several seconds to flush out dirt. Next, scrub away mineral buildup off the fill cap. If you observe cracks or significant wear and tear, replace the valve. 
  • Clean the valve tube: Debris lodged in the valve tube could also be the culprit. Turn off the water supply and take out 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 confirm 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 when the tank has filled. If the float ball is damaged or punctured and fills with water, it keeps the tank from filling efficiently. 

Pull up the tank lid and view inside. A partially sunken float ball may be waterlogged. Before running out to buy a new ball, examine the float arm it’s attached to. If the arm is pointed too low in the tank, bend it up slightly 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 may be better to update the existing tank parts or replace the toilet entirely. 

Plugged Plumbing Vent 

Your home plumbing system features vents that enable air to enter the pipes. If they become clogged, tension may build inside of the pipes, preventing 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 check for clogged plumbing vents. Look for long, vertical PVC pipes poking up from the roof tiles. Clear away any animal nests, deep snow or other obstructions you see to ensure your plumbing works properly. 

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 issue could stem from your supply pipes. A problem with the water line itself could restrict your toilet tank from filling appropriately. It’s a good idea to hire a licensed plumber to tackle 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 identify the reason why your toilet is slow to fill and perform a budget-friendly repair. If the fixture has hit the end of its typical life span, our company can propose high-efficiency toilet replacement in the U.S.. We’ll help you pick out 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 call Service Experts Heating, Air Conditioning & Plumbing today. 

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