Why Does My Toilet Double Flush? Troubleshooting Guide From Experts

Imagine pressing the toilet handle down once to flush and unexpectedly hearing a second flush. If your toilet flushes twice, you are not the only one facing this. In fact, it is a really common occurrence.

Now, you might wonder, why does my toilet double flush? Well, there might be many causes – maybe it’s the toilet flapper that’s not functioning well or your tank discharging too much water. Or, there might be some issues with the fill valve adjustment.

Whatever the issue, you might fix it by yourself or, even better, ask for professional help. Read on to know more!

Toilet Flushes Twice? Here’s Why

Ever wondered how your toilet functions? When you are done performing the “business” in your toilet, it is sucked through a bent pipe by gravity. From the toilet bowl, more water gets drawn below when the water plugs against the air underneath, creating suction.

As this depends on the rate of water flow, it stops working when the rate becomes too low. Thus, a gurgling sound is often heard when the seal breaks.

However, when the toilet flushes twice, it indicates that the bowl still receives water even though the flush stopped. It might be due to too much water cascading down into your toilet bowl, pushing a double flush.

Let us explore some more issues below and some easy fixes to stop the double flush.

Toilet Flapper Malfunctioning

Often, toilet flappers are the real culprits behind your double flushing problems. Every time you flash, these are responsible for delivering water from the toilet tank to the bowl.

However, if your flapper stays up for too long, your toilet might flush twice. After a flush, the generic toilet flappers are considered too lightweight to fall back into position. Or, flappers cannot just offer the perfect seal.

No matter what the issue is, water gets through and flushes your toilet again.

Other Common Flapper Issues

  • Toilet flappers dry out if the toilet is not in use for a long time without any water in its tank. This might have stopped the rubber from offering the perfect seal.
  • Its chains might be inappropriately adjusted. Thus, to effectively plug the water inside the tank, the flapper needs adjusting.

Replacing Your Toilet Flapper

Observe to see if your toilet flapper needs any sort of adjustments or replacements. If they do, follow the steps below:

  • Turn the Water Off

Shut the water supply off to your toilet. You can do it by closing its shut-off valve. If you are not much concerned about toilet shut-off valve, please read these article.

  • Flush

Next, flush the toilet multiple times to drain excess water, emptying the tank.

  • Detach the Flapper

Unclip the old flapper to detach them from your flush valve. Do not fret if the chain comes off in the process, as the new flapper would have a new chain.

  • Pull It

Drag your old flapper to free it from the overflow outlet. If made of rubber, the flapper will easily come off. On the contrary, plastic flappers will emit a popping sound.

  • Stick to the Flush Valve

Before you slide your new flapper over a tubular overflow valve, attach it to a flush valve.

You may read our guide on different toilet flushing systems available in the market.

  • Adjust Your Chain Length

Ensure that it goes straight up and down as much as possible. Also, note that it has low slack. Remember that the flapper might not perform efficiently if the chain is too tight or has excess slack.

  • Test It

Open your water supply to see if it’s working.

Toilet Fill Valve Issue: Too Much Water Flows Through

If you are still asking yourself, “Why does my toilet double flush?” probably it’s because your flush is really powerful or too weak. Adjusting your toilet fill valve will let the appropriate amount of water replenish your toilet tank.

When water levels inside a toilet tank rise, it causes water to gush out, stimulating a double flush.

Two Ways to Adjust the Fill Valve

  • Float Arm: Employ a screwdriver and use it to lower the float arm to adjust the valve’s screw on top.
  • Float Cup: For these fill valves, squeeze the cup and slide down the cup to lower the water level of the tank.

You might even need to remove and replace the fill valve to fix the double flush issue.

How to Remove the Fill Valve?

Before removing it you must know which types of toilet fill valve will most fit in your toilet tank. If you know your valve types, here’s the process for you.

  1. Take off the tank top.
  2. Take off the refill tube.
  3. Keep flushing until your tank is empty.
  4. Dry your toilet tank using a rag or sponge. Keep a bucket below your supply tube to keep water from spilling out.
  5. Remove your coupling nut away from its shank.
  6. Using the adjustable wrench, loosen the locknut and remove it. Finally, remove your fill valve and get a brand new valve as replacement. We recommend you to read our toilet fill valve buying guide to get the best one.

How to Replace the Fill Valve?

Let’s go through the step-by-step process.

Step 1: Switch Off the Water Supply

Locate your shut-off valve and then rotate it clockwise.

Step 2: Gather the Current Fill Valve

Place your rubber washer out of the kit and take it to your fill valve tailpiece’s bottom flange. Keep in mind to make sure that your fill valve fits your toilet. Move the screw on your stem piece till you reach the right height.

Step 3: Insert the Valve

Put back your fill valve and attach the water supply and nut to the bottom.

Step 4: Establish a Fill Hose

Examine your rubber tube to get the right length by trimming it to adjust your toilet. Next, place an end on the fill valve’s top. On the tube’s other end, place the adapter and link its adapter.

Step 5: Examine the Repair

Switch on the water supply. Now, rotate the valve anti-clockwise till you feel the resistance. Next, fill your toilet tank up to its marked line to see if the problem is solved or not.

Here we simply discuss about the replacement process. Anyway, we published an exclusive guide on toilet flush valve replacement, please do read it.

Final Words

This is a wrap-up for now. We hope that the solutions mentioned above have done wonders for you, and you now have the answer to your question –why does my toilet double flush?

Still, if you need professional help, do go for it!

Hello, I'm Jon C. Brown, an expert in the field of toilets. With over 15 years of experience in this industry, a significant portion of my life has been devoted to crafting high-quality toilets and bathrooms. Consequently, I've received countless inquiries about the toilet and bathroom industries. That's why, I've launched this website to provide top-notch solutions for all your toilet and bathroom related needs.

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