Why Is My Toilet Slow to Fill?

Is your toilet tank filling more slowly than usual? This is a frequent toilet issue with numerous possible causes. Luckily, none of them are serious concerns or expensive to address. Follow this guide to get your slow toilet working properly again. 

How to Repair a Slow-Filling Toilet 

Finding out why your toilet is slow to refill is step #1 for fixing it. Think about these possible reasons and how to handle each one. 

Partially Closed Water Supply Valve 

Look behind the toilet for the water supply hook-up attached to the wall. You’ll find a valve connecting to it, which enables you to close 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 is close 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 degrade, clog or reposition out of alignment after years of use, preventing the tank from filling appropriately. Follow these instructions to adjust, unclog or fix the fill valve: 

  • Find the fill valve: Open the toilet tank lid and find the fill valve inside. It’s commonly installed 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: Be certain the fill valve is secure and evenly connected to the tube. Change the fill valve height if needed by turning the adjustment knob (common to newer toilets) or find a flathead screwdriver and loosen the adjustment screw (required for older toilets). Next, verify that the water level is about one inch below the top of the overflow tube. 
  • Wash the fill valve: To eliminate mineral buildup and other gunk 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 the water flow for several seconds to flush out the buildup. 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 trapped in the valve tube could also be the culprit. Turn off the water supply and remove the valve hardware. Then, run a thin wire or bottle brush down the tube. Start the water supply slightly to rinse away the remaining residue. Replace 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, closing the fill valve once the tank has filled. If the float ball is filled with water, it prevents the tank from filling correctly. 

Remove the tank lid and view inside. A partially submerged 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 directed too low in the tank, bend it up somewhat to elevate the ball’s height. 

If that fails to solve the issue, 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 upgrade the existing tank parts or change out the toilet entirely. 

Clogged Plumbing Vent 

Your home plumbing system uses vents that enable air to enter the pipes. If they become clogged, pressure may build inside of the pipes, stopping 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’ll need to jump up on the roof to search 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 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 problem could stem from your supply pipes. A leak or blockage in the water line could restrict your toilet tank from filling correctly. 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 this is happening and perform a cost-effective repair. If the fixture has hit the end of its average life span, our specialists can suggest high-efficiency toilet replacement in the U.S.. We’ll help you find the replacement model and install it on your behalf. Relax knowing that every job we perform is backed by a 100% satisfaction guarantee! To schedule a visit from us, please call Service Experts Heating, Air Conditioning & Plumbing today. 

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