Why Is My Toilet Slow to Fill?

You flushed and now you have to wait; sound familiar? This is a known toilet issue with several possible reasons. Luckily, none of them are serious concerns or expensive to correct. Follow this guide to get your slow toilet working properly again. 

How to Fix a Slow-Filling Toilet 

Learning why your toilet is slow to refill is the first step toward fixing it. Keep in mind these potential reasons and the best way to handle each one. 

Partially Closed Water Supply Valve 

Look behind the toilet for the water supply hose attached to the wall. You’ll find a valve connecting to it, which enables you to turn 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 you’ll find connected to the top of a vertical tube device in the toilet tank, regulates the water flow into the tank. A toilet fill valve might degrade, clog or shift out of alignment after years of use, hindering the tank from filling appropriately. Follow these instructions to adjust, clear out or fix the fill valve: 

• Locate the fill valve: Remove 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 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. Adjust the fill valve height if needed by twisting the adjustment knob (found in newer toilets) or loosening the adjustment screw with a flathead screwdriver (required for older toilets). After that, check that the water level is about one inch below the top of the overflow tube. 
• Wash the fill valve: To remove mineral buildup and other dirt from the valve, first shut off the water in the rear of the toilet and remove the fill cap. After that, slowly turn the water back on, cupping your hand over the valve to keep from being sprayed. Let the water flow for a few seconds to flush out debris. Next, scrub away mineral buildup on the fill cap. If you detect cracks or significant 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 remove the valve hardware. Afterward, run a thin wire or bottle brush down the tube. Turn back on the water supply slightly to clean away the remaining residue. Reconnect the valve hardware and see 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 is full. If the float ball is filled with water, it prevents the tank from filling efficiently. 

Take off the tank lid and view inside. A partially sunken float ball may be waterlogged. Before you replace the ball, check the float arm it’s attached to. If the arm is fixed too low in the tank, bend it up a little bit to raise the ball’s height. 

If that fails to solve the issue, then it might be time to just replace the component entirely. But it’s worth remembering that this is an older toilet design, so it may well be better to update 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 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 overflow. 

You need to get on the roof to check for clogged plumbing vents. Start looking for long, vertical PVC pipes poking up from the shingles. Do away with any animal nests, deep snow or other obstructions you find 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 a good idea to hire a licensed plumber to tackle 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 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 hit the end of its useful life span, our company can suggest high-efficiency toilet replacement in the U.S.. We’ll help you decide on the replacement model and install it for you. 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.