Why Is My Toilet Slow to Fill?

Is your toilet tank filling more slowly than usual? This is a common toilet issue with multiple possible culprits. Luckily, none of them are major concerns or costly to fix. Follow this guide to get your slow toilet working quickly again. 

How to Repair a Slow-Filling Toilet 

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

Partially Closed Water Supply Valve 

Check behind the toilet for the water supply line connected to the wall. You’ll find a valve connected to it, which enables you to close off the water during toilet repairs and replacements. Examine the value to ensure it is fully open. 

Trouble with the Fill Valve or Tube 

The fill valve, which is connected to the top of a vertical tube-shaped part in the toilet tank, controls the water flow into the tank. A toilet fill valve could break down, clog or shift out of alignment after years of use, hindering the tank from filling right. Follow these instructions to adjust, clear out or fix the fill valve: 

  • Locate 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 connecting to the supply tube and shut-off valve. 
  • Adjust the fill valve: Be certain the fill valve is secure and evenly fastened to the tube. Adjust the fill valve height if needed by twisting the adjustment knob (found in newer toilets) or find a flathead screwdriver and loosen the adjustment screw (required for older toilets). Next, check that the water level is roughly one inch below the top of the overflow tube. 
  • Wash the fill valve: To get rid of mineral accumulation and other gunk 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 keep from being sprayed. Let some water flow for 15-20 seconds to flush out debris. Next, scrub away mineral buildup off the fill cap. If you observe cracks or excessive wear and tear, replace the valve. 
  • Clean the valve tube: Dirt inside the valve tube could also be to blame. Shut off the water supply and remove the valve hardware. Then, run a slim wire or bottle brush down the tube. Open the water supply slightly to flush away the excess residue. Re-install 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, sealing the fill valve when the tank has filled. If the float ball is filled with water, it blocks the tank from filling efficiently. 

Remove the tank lid and view inside. A partially sunken float ball could be waterlogged. Prior to replacing the ball, check the float arm it’s secured to. If the arm is directed too low in the tank, bend it up somewhat to raise the ball’s height. 

If that does not do the trick, then it might be time to just replace the component entirely. Just remember that this is old toilet technology, so it might possibly be better to update the existing tank hardware or replace the toilet altogether. 

Clogged Plumbing Vent 

Your home plumbing system features vents that permit air to enter the pipes. If they end up clogged, stress may build within 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 flood. 

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 roof tiles. Get rid of any animal nests, deep snow or other obstructions you see to help your plumbing work as intended. 

Leaky or Blocked Pipe 

If you can’t find anything wrong with the water supply valve, fill valve and tube, float ball or plumbing vents, the slow toilet problem could stem from your supply pipes. A leak or blockage in the water line 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 

If these tips did not handle your issue, look to Service Experts Heating, Air Conditioning & Plumbing for dependable toilet repair in the U.S.. We can pinpoint the reason why your toilet is slow to fill and perform a cost-effective repair. If the fixture has reached 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 execute is protected 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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