Although it may seem harmless to flush the toilet while in the shower, doing so might have disastrous results. It’s not a good idea to flush the toilet while you’re in the shower since the force of the flush might cause a drop in water pressure.

This can create a suction effect that draws water out of the shower and tub, leading to gurgling noises and flooding. 

This article will explain what happens when you flush the toilet while showering and offer advice on avoiding this scenario. 

What Happens When You Flush The Toilet While Showering?

The water pressure in the shower temporarily drops when the toilet is flushed. This can cause a gurgling sound because the water in pipes is forcibly expelled and pulled back into the toilet bowl or sink. The suction created by flushing can also draw water out of a shower or tub, causing flooding.

Showering And Flushing: How To Maintain Them

1. Limit Using The Flush When Someone’s In the Shower

If someone is taking a shower and you flush the toilet, it might drastically lower the water pressure and disrupt their routine. Because of this, it’s preferable to use a different bathroom or wait until the shower is through before flushing the toilet.

2. Increase Water Availability

The water pressure in your plumbing system relies on having a steady flow of water. Expand your water supply pipe and install a larger water heater. This will guarantee plenty of water for things like showers and toilet flushes.

3. Reduce Water In The Tank

It takes a lot of water to flush the toilet, mainly when the tank is full. You may lower the tank’s water level by reducing the flapper or purchasing a high-efficiency toilet to save water when flushing. This will help conserve water and decrease the strain on your plumbing system whenever you flush the toilet.

What Happens When You Flush The Toilet While Showering

4. The Shutoff Valve

A shutoff valve can be installed to relieve pressure in the plumbing system during flushing. The valve is wired to a switch that shuts off water to the toilet whenever it is flushed, preventing any loss of water pressure and minimizing plumbing system disruptions. A shutoff valve is a simple and effective solution to keep your plumbing safe during flushing.

5. Thermostatic Mixing Valve

Installing a thermostatic mixing valve may further lessen the strain on your plumbing system during flushing. The valve controls the flow and pressure of cold and hot water supplies. This prevents the water pressure in the shower from fluctuating unexpectedly when the toilet is flushed.

6. Install A Larger Hot Water Tank

A bigger hot water tank can be installed to provide more hot water for showers and toilets. This can relieve some of the strain on the pipes while still delivering adequate hot water for washing and flushing. A bigger tank also helps save money on utility bills since it requires less frequent reheating of the hot water supply.

7. Upgrade The Pipes With More Efficient Pipes

Finally, replacing older pipes with newer, more efficient ones can help lessen the impact of water pressure and other plumbing-related disruptions. 

PEX piping and other modern, long-lasting plumbing systems are engineered to reduce water resistance and boost water pressure. This can assist in keeping your water pressure steady if you need to flush the toilet while showering.

Why A Shower Goes Cold When A Toilet Is Flushed

1. The Plumbing Setup

Showers become cold when you flush the toilet because of the plumbing configuration. When a toilet is flushed, the water pressure suddenly drops. This pressure drop might disrupt the plumbing system, leading to more cold water in the shower and bathtub.

2. Turning On The Shower Before Flushing

If you switch on the shower before the flush, the shower can go cold when you flush the toilet. This is because the water pressure in the shower will drop, making the shower experience less than pleasant.

3. Insufficient Water Supply

A lack of available water supply may also account for the sudden loss of hot water in the shower after flushing the toilet. Flushing could further reduce the pressure if your home already has a low water supply. 

Because of this, your plumbing system may have trouble keeping up a constant pressure, which leads to cold water coming out of the shower head.

4. The Toilet Flush

There is also a correlation between the water pressure in your plumbing and the toilet flush you use. When using an older toilet with a large tank, the flushing process will consume more water than newer models, which might result in a rapid drop in water pressure. 

Modern toilets have smaller tanks because they consume less water, which means less water is wasted and less possibility of getting a cold shower after flushing.

What Happens When You Flush The Toilet While Showering

5. The Tank is Too Small 

If your hot water tank isn’t big enough, your shower can go chilly after you flush the toilet. If the tank isn’t big enough, the pressure in the pipes will drop suddenly when you flush, leaving you with a chilly shower or no water.

6. Flushing Uses Up Hot Water 

When you flush the toilet, it might use up hot water, causing your shower to become chilly. The shower’s water temperature drops due to a drop in pressure since the tank’s hot water supply is diverted to the toilet during a flush.

7. Malfunctioning Valve Is Letting Cold Water

A broken valve that permits cold water to flow into the hot water line might also result in a cold shower after flushing the toilet. This may occur if the valve becomes jammed open, enabling cold water to flow into the hot water pipe and upsetting the delicate pressure balance.

7. Pipes are Too Small and Have Air Pockets

Lastly, a shower’s temperature might drop when a toilet is flushed if the pipes are too narrow or contain air pockets. If air pockets are in your lines, it will be more difficult for your plumbing system to sustain constant pressure, which might result in a drop in water temperature in your shower after you flush your toilet.

Why Does Flushing The Toilet Make The Shower Hot?

Water pressure suddenly increases when a toilet is flushed. Because of the boost in pressure, hot water may travel further through the pipes and reach the showerhead faster. To avoid this, check that the water pressure is enough and the pipes are the right size for your house.

Why Does Flushing The Toilet Affect The Shower?

Depending on how your plumbing system is set up, flushing the toilet might create a rapid drop in water pressure or a rise in water pressure, throwing off the system’s delicate pressure balance. As the pressure in the system shifts, the shower temperature may change when the toilet is flushed.

To guarantee the best shower performance, check that your plumbing system is adequately sized and has adequate water pressure. You may lessen the load on your shower even more by using a modern, low-flow toilet and turning off the water supply to the shower beforehand.

What Happens If The Toilet Is Connected To Hot Water?

Flushing a toilet linked to a source of hot water might result in an immediate temperature rise. This rapid temperature rise can reduce water pressure by overloading the hot water tank.

The abrupt pressure drop might cause the shower to turn cold if the plumbing system cannot keep up with the pressure. There’s also the possibility of a rise in the monthly water bill due to the increased use of hot water needed to replenish the storage tank.

Is It Okay To Flush The Toilet With Hot Water?

No. If you want to keep the toilet’s flushing pressure constant, you shouldn’t use hot water. This can throw off the pressure balance in the plumbing system, resulting in a sudden loss of hot water in the shower whenever the toilet is flushed.

Another potential downside is the additional cost of heating water to replenish the tank. To avoid unpleasant surprises, check to see that the toilet has a connection for cold water and that the shower is turned off before you flush. 

This will assist in keeping the plumbing system in good condition and provide a more enjoyable showering experience.

Does Hot Water Break Down Toilet Paper?

No. Toilet paper does not degrade in hot water, unfortunately. It is advised that you use hot water while flushing the toilet, as this will aid in breaking down and dissolving any solid waste.

However, you should be aware that flushing hot water can generate pressure shifts, which might throw off the pressure equilibrium in your plumbing system and suddenly force the shower to become cold.