Why Is My Toilet Slow to Fill?

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

How to Fix a Slow-Filling Toilet 

Understanding why your toilet is slow to fill is step #1 for fixing it. Keep in mind 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 see a valve attached to it, which allows you to turn off the water during toilet repairs and replacements. Make sure this value is open by turning it to the left. 

Problems with the Fill Valve or Tube 

The fill valve, which you’ll find close to the top of a vertical tube-shaped part in the toilet tank, manages the water flow into the tank. A toilet fill valve may wear out, clog or move out of alignment after years of use, preventing the tank from filling properly. 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 usually secured 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: Be sure that the fill valve is secure and evenly fastened to the tube. Alter the fill valve height if necessary by turning the adjustment knob (typical to newer toilets) or loosening the adjustment screw with a flathead screwdriver (required for older toilets). Then, check that the water level is approximately one inch below the top of the overflow tube. 
• Clean the fill valve: To take out mineral buildup and other gunk from the valve, first shut off the water in the rear of 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 the water flow for 15-20 seconds to flush out the buildup. Next, scrub away mineral buildup on the fill cap. If you observe cracks or excessive wear and tear, replace the valve. 
• Clean the valve tube: Dirt lodged in the valve tube could also be the culprit. Shut off the water supply and remove the valve hardware. Then, run a slim wire or bottle brush into the tube. Turn back on the water supply slightly to rinse away the leftover residue. Re-install 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 blocks the tank from filling properly. 

Remove the tank lid and peek inside. A partially sunken float ball may be waterlogged. Before running out to buy a new ball, check the float arm it’s connected to. If the arm is pointed 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 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. 

Blocked Plumbing Vent 

Your home plumbing system features vents that permit air to enter the pipes. If they are clogged, pressure may build throughout the pipes, blocking 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 look 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 problem could stem from your supply pipes. A problem with the water line itself could restrict your toilet tank from filling correctly. It’s best 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 dependable toilet repair in the U.S.. We can figure out the reason why your toilet is slow to fill 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 for you. Rest assured that every job we perform is supported by a 100% satisfaction guarantee! To schedule a visit from us, please contact Service Experts Heating, Air Conditioning & Plumbing today.