Why Is My Toilet Slow to Fill?

You flushed and now you have to wait; sound familiar? This is a frequent toilet problem with multiple possible causes. Thankfully, none of them are major concerns or costly to deal with. Follow this guide to get your slow toilet working properly again. 

How to Fix a Slow-Filling Toilet 

Learning why your toilet is slow to refill is step #1 for fixing it. Think about these possible reasons and how to deal with each one. 

Partially Closed Water Supply Valve 

Take a peek behind the toilet for the water supply hose connected to the wall. You’ll see a valve connected to it, which allows you to close off the water during toilet repairs and replacements. Check this valve to make sure it’s completely open. 

Issues 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 level flowing 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 appropriately. Follow these tips to adjust, clear out or fix the fill valve: 

  • Search for the fill valve: Remove the toilet tank lid and find the fill valve inside. It’s commonly 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. Alter the fill valve height if needed by twisting the adjustment knob (typical to newer toilets) or find a flathead screwdriver and loosen the adjustment screw (required for older toilets). After that, ensure that the water level is about one inch below the top of the overflow tube. 
  • Wash the fill valve: To get rid of mineral buildup and other debris from the valve, first shut off the water in the back of the toilet and remove the fill cap. Then, slowly turn the water back on, cupping your hand over the valve to keep from being sprayed. Let some water flow for 15-20 seconds to flush out debris. Next, scrub away mineral buildup from 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 the culprit. Turn off the water supply and take out the valve hardware. Afterward, run a thin wire or bottle brush down the tube. Start the water supply slightly to clean away the remaining residue. Replace the valve hardware and confirm if the toilet fills properly. 

Waterlogged Float Ball 

The float ball in older toilet models rises with the water level, sealing the fill valve once the tank has filled. If the float ball takes on water, it blocks the tank from filling properly. 

Take off the tank lid and view inside. A partially submerged float ball might 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 that fails to solve the issue, you may be able to install a new float ball. Just remember that this is an older toilet design, so it may well be better to upgrade the existing tank hardware or switch out the toilet completely. 

Clogged Plumbing Vent 

Your home plumbing system features vents that enable air to enter the pipes. If they become clogged, stress may build within the pipes, blocking the water from flowing. This can, in turn, make your toilet slow to fill or even cause the bowl to overrun. 

You should grab a ladder and climb up on the roof to look for clogged plumbing vents. Start looking for long, vertical PVC pipes poking up from the roof tiles. Do away with any animal nests, deep snow or other obstructions you find 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 dilemma could stem from your supply pipes. A problem with the water line itself could stop your toilet tank from filling properly. It’s a good idea to hire a licensed plumber to tackle 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 come to the end of its average life span, our team can suggest high-efficiency toilet replacement in the U.S.. We’ll help you pick out the replacement model and install it on your behalf. You can relax knowing that every job we execute is backed by a 100% satisfaction guarantee! To schedule a visit from us, please connect with Service Experts Heating, Air Conditioning & Plumbing today. 

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