When to Replace Toilet Flush Valve

Best Selling Toilet Flush Valve

Maintaining your toilet in top working condition makes both environmental and economic sense since you can conserve water and save money. It is said that toilet flushing accounts for up to 20% of domestic water consumption, therefore, even a small leakage degenerates quickly to a bottomless pit for your hard-earned cash. For that reason, you need to act swiftly if your toilet flush valve is damaged or develops a fault.

What is a Flush Valve?

For a standard gravity-flush toilet, a flush valve is a large metal or plastic assembly that sits in the middle of the toilet tank. It is meant to control water flow into the toilet bowl to flush down the waste into the drains.

The flush valve system includes a long overflow tube connected to the flush valve seat which fits into the large opening at the bottom of the tank. There is also a flapper that works to seal the opening and holds water in the tank until flushing is done.

When to Replace Toilet Flush Valve

The clearest sign that your toilet requires flush valve replacement is when your toilet runs continuously. This is even after the flapper, fill tube, flush valve seat, rubber gasket and other components that may possibly cause continuous running toilet have been taken care of.

The possible reason why your toilet continues to run is that the flush valve seat is worn out or cracked, thus preventing the flapper from delivering a watertight seal. If your toilet flapper is in good shape but does not seal well, most likely your it is the old toilet flush valve that requires replacement.

Even though it is difficult to do toilet repairs and replacements, an average handy homeowner can effectively manage to replace a toilet flush valve. We’ll get into the details on how to replace your toilet flush valve.

 How Can I Replace My Toilet Flush Valve?

A leak from your toilet tank could be occasioned by any of the following reasons:

  • The flush valve is damaged
  • Worn out flapper
  • The flush valve does not seal tightly because of excess mineral deposits build-up

You can confirm the leaks by turning off the water supply to the tank, mark the water level, and wait for a few minutes and check whether water has dropped from the level you marked. If it has, you have a leaking flush valve.

Even if it is a small leak, it is important not to ignore it as it might progress to damage your floor and raise your water bills. So, how can you fix it all by yourself?

Tools and Supplies Needed

  • Adjustable wrench
  • Hacksaw blade – if necessary
  • Channel locking pliers
  • Large slot screwdriver
  • Replacement flush valve
  • Water supply tube – if necessary
  • Two toilet tank bolts
  • Bucket and an abrasive sponge


Turn off the Water Supply

Start by shutting off the water coming to the toilet by closing the water supply valve located at the tailpiece on the toilet’s fill valve. Often, this is found at the bottom left side of most toilet tanks. But if your toilet does not have a shutoff valve or does not shut off the water completely, you can shut the water from the main shutoff for the whole house.

Flush down the toilet and then remove the toilet tank lid. Use the sponge to remove as much water remaining in the tank to allow easy and messy-free removal of the water tank. Use the channel locking pliers or the adjustable wrench to unscrew the water supply tube from the end of the toilet fill valve.

 Remove the Tank Bolts

How to fix water leaking past toilet bolt? - Home Improvement ...

Your tank bolts may come with a second set of nuts holding onto the toilet tank and they require removing too. If they are so rusted, cut them off with the hacksaw blade. Equally, you can cut through the rubber washer. However, you can reuse newer tank bolts if they are in good shape or replace them when replacing the flush valve.

Remove the Toilet Tank

The toilet water tank is often held in place by tank bolts that are threaded through the holes in the bottom of the tank down through the top of the bowl, then secure with nuts. Often, the nuts threaded onto the water tank bolts are simple wing nuts that you can easily remove by hand. If your tank has the traditional nuts, you can use the pliers or wrench to unscrew.

Be sure to unscrew the nuts while holding the bolt in place with a screwdriver from the insider so as to stop it from spinning. Should the bolts refuse to come out due to corrosion, you can cut them off with the hacksaw blade. Once you remove the bolts, carefully remove the tank from the bowl and set a stable place to work on it.

Remove the Old Flush Valve

Toilet: can I replace this Mansfield flush valve with a flapper ...

After the tank bolts are out, you can now remove the large foam gasket covering the plastic mounting nut on the tailpiece of the flush valve. Use the channel-lock pliers to unscrew the mounting nut. Once the nut is removed, carefully pull the flush valve out of the tank. Clean the tank before you install a new flush valve and other components.

Installing the New Flush Valve

New Tank Flush Valve

Installing the correct size adjustable new flush valve is the best option since you can set it to whatever height necessary. Regardless, most universal flush valves work with most toilet models and you can find one from your local store.

Start by sliding the large beveled side onto the end of the toilet flush valve in a way that the side of the washer faces down. Insert the flush valve through the opening in the toilet tank from the inside. Carefully, orient the toilet flush valve unit inside the tank as per the manufacturer’s instructions.

Often, the vertical overflow tube should be positioned near the back of the tank. Also, thread the mounting nut onto the flush valve tailpiece from the exterior of the tank. Tighten the mounting nut with the channel-lock pliers. While tightening the nut, slightly compress the beveled side washer inside the tank to seal the flush valve opening. However, be careful not to over tighten the nut because you might end up breaking it.

Put the large foam gasket over the toilet flush valve tailpiece extending through the bottom of the tank. The gasket will serve as a shock absorber that cushions the tank when setting the tank on the toilet bowl.

Install the New Tank Bolts

Stainless steel universal water tank bolt

Thread the tank bolts through holes from the bottom of the tank and place a rubber washer under the head of each bolt. Equally, put a rubber washer and metal washer threaded over bolts of each bolt from the outside.

As such, you would have sandwiched the porcelain toilet water tank with rubber washers. Thread a mounting nut onto each of the bolts and tighten enough to only compress the rubber washer just a little.

Install the Tank onto the Bowl

How to Install a Toilet in 8 Steps - This Old House

With a lot of care put the toilet tank onto the bowl with the tank bolts sliding down through the holes in the top of the bowl. Thread the metal washers and nuts onto the bolts and tighten them by hand. Proceed to tighten the nuts by the wrench enough to hold the toilet tank in position without cracking the porcelain material. Alternatively, you can let the tank fill with water and push the tank down thus allowing you to tighten the nuts properly.

 Connect the Water Supply

Connection to toilet tank | Toilet tank, Leaky toilet, Leaking toilet

Once the toilet tank is well secured on the toilet bowl, reattach the water supply tube to the tailpiece on the fill valve. You may also replace the water supply tube with a new one if necessary at this point. Once secure, turn on the water to fill the toilet tank. Connect the flapper chain to the toilet handle from the inside.

You may adjust the flush valve height so as to keep the water level at the recommended line with the overflow tube being at about 1-inch above that. Flush the toilet and check whether the flush valve and everything else works well.

When Should I Replace My Toilet Fill Valve?

The fill valve on a standard flush toilet is not essentially complicated. A fill valve is a simple tube fitted with a shut-off valve that’s connected at the bottom of the toilet tank to the water supply.

It also features an air-filled cup or ball that is connected to the fill valve. The cup or ball floats in the water inside the tank and triggers the valve shutting off when the water level reaches a particular height.

However, fill valves just like the flush valves wear out and so they require to be replaced to keep your toilet working efficiently. So, when should you replace your toilet fill valve? There are a couple of signs that indicate that your toilet fill valve requires immediate replacement. Here are some of the common signs:

Your Toilet Running Continuously

The most common sign is your toilet running continuously. This is usually occasioned by a leaking flapper which allows the toilet tank to drain slowly, thus making the fill valve run continuously. It can also happen due to the fill valve being worn out.

To determine if the problem is the flapper or valve, you can put a dye into the water inside the toilet tank. Allow it to settle for a few hours the flush to check and see if the eater in the bowl has changed colour. If the colour is not changed, then the problem lies with the fill valve.


When the metal components of an older ballcock style valve get won out, the toilet flush valve tends not to open and close smoothly like before. This implies that water force is directed through the aperture thus produce some odd sounds. However, you may not hear the low humming sound that is often the first noise. The sound will get louder because the metal components have loosened and the valve is almost failing.

How Can I Replace the Fill Valve?

Replacing your fault fill valve is quite easy. Follow the following steps:

Turn off the water supply

Reach the water inlet valve and shut it off and flush down the water in the water tank. The remaining water will continue leaking and you need to place a rag on the floor to catch the water that might overflow.

Loosen the Fill Valve

Loosen the fill valve from the underside of the tank to disconnect it. However, you need to detach the fill hose, which is very simple to disconnect. With the help of adjustable pliers, loosen the nut holding the fill valve inside the tank.

Replace with the New Fill Valve

Now that you have removed the old valve, it is time to install a new one. Place threaded end through the hole and hold it against the bottom of the tank. Thread a nut from the bottom of the tank and tighten it. However, be careful not to overtighten as you might damage the ceramic parts of the tank.

Secure the Water Supply

Reconnect and secure the water supply to the new fill valve. Adjust it to the new height if necessary. Reconnect the refill hose back to its place and turn on the water. When flushed, water in the tank should fill to the right level, without running or leaking from the bottom of the toilet tank.

When to replace toilet flush valve? Toilet problems are inevitable and once they occur, it is important that you take action to fix the issues or replace the fault unrepairable part. That way, you will be able to keep your toilet running efficiently and saving water in the long run.

  1. […] require cleaning regularly. When cleaning your toilet, be sure to clean outside the bowl, the tank, toilet seat and the flush handle. Additionally, disinfect your toilet brush after using it. Experts […]

  2. […] is, without a doubt, one of the best substitutes for toilet paper. However, is it vital that you first make sure that the water you are using is not […]

  3. […] need to consider how big or severe the clog is. If your toilet backs up a little and then starts to drain down slowly, then what you have is a partial clog. A […]

Leave a reply

Smart Straw
Enable registration in settings - general