Why Is My Toilet Slow to Fill?

Is your toilet tank filling more slowly than usual? This is a common toilet problem with multiple possible reasons. Luckily, none of them are serious concerns or expensive to correct. Follow this guide to get your slow toilet flowing properly again.

How to Fix a Slow-Filling Toilet

Finding out why your toilet is slow to fill is the first step toward fixing it. Consider these potential reasons and the best way to handle each one.

Partially Closed Water Supply Valve

Take a peek behind the toilet for the water supply hose attached to the wall. You’ll find a valve connecting to it, which allows you to shut off the water when your toilet is being repaired or replaced. Make sure this value is open by turning it to the left.

Trouble with the Fill Valve or Tube

The fill valve, which can be found attached to the top of a vertical tube device in the toilet tank, regulates the water flow into the tank. A toilet fill valve could break down, clog or slip out of alignment after years of use, hindering the tank from filling appropriately. Follow these tips to adjust, unclog or fix the fill valve:

  • Locate 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 attaching 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. Adjust the fill valve height if required by twisting the adjustment knob (found in newer toilets) or find a flathead screwdriver and loosen the adjustment screw (required for older toilets). After that, ensure that the water level is roughly one inch below the top of the overflow tube.
  • Clear debris from the fill valve: To remove mineral accumulation and other dirt from the valve, first shut off the water behind the toilet and take off 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 off the fill cap. If you observe cracks or significant wear and tear, replace the valve.
  • Clean the valve tube: Dirt trapped in the valve tube could also be at fault. Shut off the water supply and remove the valve hardware. Afterward, run a thin wire or bottle brush down the tube. Start the water supply slightly to flush away the leftover residue. Reconnect the valve hardware and verify if the toilet fills properly.

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 takes on water, it prevents the tank from filling efficiently.

Pull up the tank lid and view inside. A partially sunken float ball could be waterlogged. Before you replace the 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 lift the ball’s height.

If that fails to solve the issue, you may be able to install a new float ball. But it's worth remembering that this is old toilet technology, so it might possibly be better to modernize the existing tank hardware or switch out the toilet completely.

Blocked Plumbing Vent

Your home plumbing system features vents that allow air to enter the pipes. If they are clogged, tension may build throughout 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 need to get on the roof to search for clogged plumbing vents. Start looking for long, vertical PVC pipes poking up from the roof tiles. Clear away any animal nests, deep snow or other obstructions you notice to ensure your plumbing works properly.

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 dilemma 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 fix these issues.

Schedule Toilet Repair with Service Experts Heating & Air Conditioning

If these tips did not handle your issue, look to Service Experts Heating & Air Conditioning for reliable toilet repair in Longmont. We can pinpoint the reason why this is happening and perform the most appropriate repair. If the fixture has come to the end of its useful life span, our specialists can suggest high-efficiency toilet replacement in Longmont. We’ll help you pick out the replacement model and install it for you. Rest assured that every job we complete is supported by a 100% satisfaction guarantee! To schedule a visit from us, please contact Service Experts Heating & Air Conditioning today.

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