Why Is My Toilet Slow to Fill?

You flushed and now you have to wait; sound familiar? This is a known toilet predicament with numerous possible culprits. Fortunately, none of them are serious concerns or costly to deal with. Follow this guide to get your slow toilet flowing properly again. 

How to Repair a Slow-Filling Toilet 

Finding out why your toilet is slow to refill is the first step toward fixing it. Think about these potential reasons and how to handle each one. 

Partially Closed Water Supply Valve 

Take a peek behind the toilet for the water supply hook-up connected to the wall. You’ll find a valve connecting to it, which allows you to shut off the water during toilet repairs and replacements. Examine the value to ensure it is fully open. 

Problems with the Fill Valve or Tube 

The fill valve, which you’ll find attached to the top of a vertical tube device in the toilet tank, regulates the water level flowing into the tank. A toilet fill valve may break down, clog or move 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: 

  • Search for the fill valve: Open the toilet tank lid and find the fill valve inside. It’s usually mounted 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 attached to the tube. Modify the fill valve height if needed by twisting the adjustment knob (common to newer toilets) or find a flathead screwdriver and loosen the adjustment screw (required for older toilets). Then, check that the water level is about one inch below the top of the overflow tube. 
  • Wash the fill valve: To take out mineral buildup and other debris from the valve, first shut off the water in the back of the toilet and take off the fill cap. Then, slowly turn the water back on, cupping your hand over the valve to avoid getting sprayed. Allow the water to flow for a few seconds to flush out dirt. Next, scrub away mineral buildup off the fill cap. If you detect cracks or significant wear and tear, replace the valve. 
  • Clean the valve tube: Debris inside the valve tube could also be at fault. Turn off the water supply and remove the valve hardware. Next, run a thin wire or bottle brush down the tube. Turn back on the water supply slightly to rinse 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 when the tank is full. If the float ball is damaged or punctured and fills with water, it prevents the tank from filling properly. 

Remove the tank lid and peek inside. A partially submerged float ball may be waterlogged. Before running out to buy a new ball, examine the float arm it’s secured to. If the arm is directed too low in the tank, bend it up somewhat to lift the ball’s height. 

If that does not do the trick, you might want to simply buy a new float ball; the average cost of this product ranges between $7-$20 in most hardware or home improvement stores. Just remember that this is an older toilet design, 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 includes vents that allow air to enter the pipes. If they end up clogged, tension may build inside of the pipes, stopping the water from flowing. This can, in turn, make your toilet slow to fill or even cause the bowl to overflow. 

You’ll need to jump up on the roof to check 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 guarantee that your plumbing can function 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 water line leak 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 

When all else fails, turn to Service Experts Heating, Air Conditioning & Plumbing for reliable toilet repair in the U.S.. We can pinpoint the reason why your toilet is slow to fill and perform a budget-friendly repair. If the fixture has come to the end of its typical life span, our team can propose high-efficiency toilet replacement in the U.S.. We’ll help you pick out the replacement model and install it on your behalf. Relax knowing that every job we complete is backed by a 100% satisfaction guarantee! To schedule a visit from us, please contact Service Experts Heating, Air Conditioning & Plumbing today. 

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