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 reasons. Thankfully, none of them are major concerns or costly to fix. Follow this guide to get your slow toilet working efficiently again. 

How to Repair a Slow-Filling Toilet 

Learning why your toilet is slow to fill is step #1 for fixing it. Think about these potential reasons and the best way to handle each one. 

Partially Closed Water Supply Valve 

Check behind the toilet for the water supply line connected to the wall. You’ll see a valve connecting to it, which allows you to shut off the water when your toilet is being repaired or replaced. Examine the value to ensure it is fully open. 

Issues with the Fill Valve or Tube 

The fill valve, which can be found connected to the top of a vertical tube-shaped part in the toilet tank, manages the water level flowing into the tank. A toilet fill valve could degrade, clog or shift out of alignment after years of use, hindering the tank from filling appropriately. Follow these instructions to adjust, unclog or fix the fill valve: 

  • Find the fill valve: Lift the toilet tank lid and find the fill valve inside. It’s usually installed 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: Check that the fill valve is secure and evenly connected to the tube. Modify the fill valve height if required by twisting the adjustment knob (typical to newer toilets) or use a flathead screwdriver to loosen and adjust (required for older toilets). After that, ensure that the water level is about one inch below the top of the overflow tube. 
  • Clean the fill valve: To eliminate mineral buildup and other dirt from the valve, first shut off the water behind the toilet and take off the fill cap. Right after that, 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 observe cracks or substantial wear and tear, replace the valve. 
  • Clean the valve tube: Debris lodged in the valve tube could also be at fault. Shut off the water supply and take out the valve hardware. Next, run a slim wire or bottle brush into the tube. Open the water supply slightly to rinse away the excess residue. Reconnect the valve hardware and see 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 once the tank is full. If the float ball is damaged or punctured and fills with water, it prevents the tank from filling correctly. 

Remove the tank lid and look inside. A partially submerged float ball may be waterlogged. Before running out to buy a new ball, look at the float arm it’s attached to. If the arm is pointed too low in the tank, bend it up a little bit to raise the ball’s height. 

If this doesn’t work, you may be able to install a new float ball. But it’s worth remembering that this is an older toilet design, so it may be better to update the existing tank components or change out the toilet altogether. 

Blocked Plumbing Vent 

Your home plumbing system uses vents that enable air to enter the pipes. If they are clogged, tension may build throughout the pipes, preventing 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 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 shingles. Get rid of any animal nests, deep snow or other obstructions you find 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 prevent your toilet tank from filling correctly. It’s a good idea 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 dependable toilet repair in the U.S.. We can figure out the reason why your toilet is slow to fill and perform a cost-effective repair. If the fixture has hit the end of its useful life span, our team can propose 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 execute is supported 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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