The toilet is one of the most essential fixtures in our homes. Its importance cannot be understated, as we rely on using a functional toilet every single day. However, it can be a cause for alarm to hear rattling, thuds, or other loud noises when you flush the toilet. Any unusual noise from the toilet usually signals a plumbing problem that needs to be explored.

The good news is that malfunctioning toilets are simple to fix. Most replacement parts are fairly inexpensive, so the repair process should be quick, cheap, and easy. Your first step is to identify the underlying issue with the help of a plumbing professional. The plumber will be able to diagnose why the toilet makes a loud noise after flushing.

Here are the reasons why there might be a noise from the pipes when the toilet flushes:

Water Hammer

A water hammer is often responsible for the strange loud noise coming from the toilet in most homes. This phenomenon is especially common in older homes with cast-iron pipes. When running water is abruptly cut off, it hammers the pipes and results in a loud thud. This noise is followed by vibrations as the pipes move around the impact.

The hammer occurs because of high water pressure, but it can also be due to faulty valves or trapped air in the system. Diagnosing the issue is tricky because the cause for the noise may come from a valve nowhere near the toilet. If left untreated, the excessive water hammer can damage the fittings in your plumbing system.

To prevent this issue, you can install a water hammer arrestor. This works by absorbing the energy produced when the water in your pipes comes to a sudden halt. Install the arrestor as close to the source of the problem as possible. This can either be attached by simply screwing them onto the pipes or installing into the wall.

High Water Pressure

The water pressure in an average household should not be higher than 60 PSI. Water pressure that exceeds this level will hurt all major plumbing fixtures. If the other fixtures near the toilet make the same noise, then high water pressure is probably the issue. To determine how high your water pressure is, you need a water pressure gauge. This gadget is inexpensive and can be purchased at your local home improvement store.

Attach the water pressure gauge to a hose bib, then read the value. If the pressure level is higher than 60, you have found the root cause of the noise from pipes when a toilet is flushed. The solution is to install a pressure regulator at the point where the water comes into your home. This will adjust the high level of water pressure and keep it at a steady threshold.

Loose Pipes

The pipes installed under your floors or in your walls are usually strapped in place to keep them from moving. However, they can weaken over time, causing the pipes to move around. Most people think that water flows through pipes smoothly, but that isn’t the case. Changes in direction and air bubbles make the water look like river rapids instead of a calm stream. This energy can be transferred to the pipes, causing them to move in all directions.

If the system has loose straps or clamps, the pipes will begin to bang into things and eventually lead to failed fitting. To confirm if this is the root cause, consult with a residential plumber to perform a visual inspection. After diagnosing this issue, you can purchase clamps or straps of the right size, then screwing them into joists or studs.

Other Noises Coming from Toilet

Sometimes, the strange toilet noise does not originate from the pipes, but it comes from the nearby parts instead. For example, the noise may be caused by a dirty valve, which you can identify by a foghorn sound. The noise might also come from a clogged toilet drain, especially if you hear a loud bang when the toilet flushes. Flushing the wrong items down the toilet often leads to clogged drains.

The noise may come from the toilet tank as well. When water travels from the supply and into the toilet tank, it flows through the float valve. This is held in the tank with a flapper. If some parts of the valve’s assembly are faulty, it leads to a water hammer effect. A fluttering sound may be heard if the valve closes and opens rapidly due to a worn-out diaphragm. The solution is to replace the flapper and fill valve.