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 costly to fix. Follow this guide to get your slow toilet functioning quickly again. 

How to Fix a Slow-Filling Toilet 

Learning why your toilet is slow to refill is step #1 for fixing it. Keep in mind these possible reasons and how to deal with each one. 

Partially Closed Water Supply Valve 

Check behind the toilet for the water supply hook-up attached to the wall. You’ll see a valve connected to it, which helps you to turn off the water when repairs or full replacement of the tank is needed. Make sure this value is open by turning it to the left. 

Problems with the Fill Valve or Tube 

The fill valve, which is connected to the top of a vertical tube device in the toilet tank, manages the water flow into the tank. A toilet fill valve might wear out, clog or shift out of alignment after years of use, hindering the tank from filling appropriately. Follow these tips to adjust, unclog or fix the fill valve: 

• Find the fill valve: Lift 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 attaching to the supply tube and shut-off valve. 
• Adjust the fill valve: Be sure that the fill valve is secure and evenly attached to the tube. Adjust the fill valve height if necessary by turning the adjustment knob (found in newer toilets) or use a flathead screwdriver to loosen and adjust (required for older toilets). Next, check that the water level is about one inch below the top of the overflow tube. 
• Clear debris from the fill valve: To remove 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. Right after that, slowly turn the water back on, cupping your hand over the valve to prevent from being sprayed by the water. Let some water flow for 15-20 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: Dirt trapped in the valve tube could also be to blame. Shut off the water supply and remove the valve hardware. Afterward, run a slim wire or bottle brush down the tube. Turn back on the water supply slightly to flush away the remaining residue. Reconnect the valve hardware and check if the toilet fills properly. 

Waterlogged Float Ball 

The float ball in older toilet models rises with the water level, sealing the fill valve once 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 you replace the ball, look at the float arm it’s secured to. If the arm is pointed too low in the tank, bend it up a little bit to elevate the ball’s height. 

If that fails to solve the issue, 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 be aware that this is an older toilet design, so it might possibly be better to modernize the existing tank hardware or switch out the toilet completely. 

Clogged Plumbing Vent 

Your home plumbing system uses vents that allow air to enter the pipes. If they end up being clogged, stress may build throughout the pipes, blocking the water from flowing. This can, in turn, make your toilet fill slowly or even cause the bowl to flood. 

You should grab a ladder and climb up 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 see 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 issue could stem from your supply pipes. A leak or blockage in the water line could restrict your toilet tank from filling correctly. It’s a good idea to hire a licensed plumber to fix these issues. 

Schedule Toilet Repair with Service Experts Heating, Air Conditioning & Plumbing 

Is your toilet still not working right? Turn to Service Experts Heating, Air Conditioning & Plumbing for dependable toilet repair in the U.S.. We can figure out the reason why this is happening and perform a cost-effective repair. If the fixture has reached the end of its average life span, our company can suggest high-efficiency toilet replacement in the U.S.. We’ll help you pick out the replacement model and install it on your behalf. Rest assured that every job we execute is backed by a 100% satisfaction guarantee! To schedule a visit from us, please contact Service Experts Heating, Air Conditioning & Plumbing today.