Can You Flush The Toilet When The Power Is Out?

Power outages, an increasingly common occurrence in society today, can be extremely unpleasant, inconvenient, and potentially dangerous. While many of your home’s general functions will be hindered, some processes will be able to continue. The toilet’s ability to function during a power outage depends on several factors.

Suppose the toilet in your home is of the standard gravity-flush variety with municipal water. In that case, you should be able to flush the toilet during power outages. The same applies if you have a reservoir supplying water to your toilet. Septic tank systems and upflush toilets may not function.

It’s important to understand the system you have in place in your home to establish if it is safe, wise, or even possible to flush your toilet during a power outage. Some systems will function perfectly without electricity, while others may not. Others will work for a limited period before problems start to arise.

Toilet, Flushing Water, close up
Image from Lange Plumbing & Fire Protection

Can You Flush The Toilet When The Power Is Out?

With increased natural disasters and numerous other issues, power outages are becoming more commonplace. It’s important to know how to function during power outages while ensuring we do not incur any damage to our homes.

Equipped with a certain degree of knowledge about how your home functions, you should be able to prepare sufficiently for any unexpected power outage.

Generally speaking, your toilet’s ability to flush during power outages will depend on three factors:

  • The type of sewer system
  • The type of toilet
  • The type of water supply

Combining these three factors will determine whether your toilet will function optimally during a power outage, for a short while before causing problems, or be unable to function.

Once you are aware of the toilet’s ability to function during these periods, you will be able to take the necessary measures to ensure your household can perform basic human functions while the power is out.

When The Toilet CAN Be Flushed During A Power Outage

There are some cases where your toilet can be flushed during a power outage with no issues whatsoever. Suppose you are connected to a municipal supply of water. In that case, you will most likely be able to flush your toilet with no issues.

gravity-flush toilet
Image from Annapolis Home Hardware Building Centre

This is only true if your toilet is of the standard gravity-flush variety. This type of toilet is not generally affected when the power goes out, as the entire system relies solely on gravity to function effectively.

Provided there is still a fully functional water supply and your sewage system does not require electricity, you should have no issue flushing your toilets. Provided the wastewater vanishes down the toilet bowl when you depress the flush and the toilet’s tank refills with water, you should not encounter any issue.

Bear in mind when flushing your toilet that there may be a limited supply of water that may run out before the electricity returns.

If you live in an urban – or suburban – area with a relatively high population density, you should be able to flush your toilet without the need for any electricity. This is due to large holding tanks that function using gravity to supply the homes in the area.

Gravity will create sufficient pressure to allow the water supply and wastewater systems to function effectively without any disturbances in the flow.

a reservoir tank
Image from The Haiti Water Project

If you rely on water from a well, you will be able to flush your toilets during power outages, provided you have a reservoir tank. Bear in mind that you will only be able to flush your toilet as long as there is water in the tank, as no new water will be pumped into the reservoir while the power is out.

When The Toilet CANNOT Be Flushed During A Power Outage

Suppose your wastewater system relies in any way on electricity. In that case, you will naturally not be able to flush your toilets conventionally while the electricity is out.

Many septic tank systems rely on a pump to remove the effluent from the tanks to the drain field or any other treatment system located at a higher level. While the power is out, you will be able to flush the toilet, provided you have a water supply.

However, without the tank being emptied by the pump, it can quickly overflow and cause a backing up of wastewater into your home.

upflush toilet
Image from Jenner’s Plumbing

Certain types of toilets require electricity to function, such as upflush toilets. This type of toilet is plugged directly into a wall outlet. Electricity is required to provide power to the pump that transfers waste to the sewer system. If there are macerating blades in the system, these too will require electricity.

As a result, this type of toilet system will be unable to flush whatsoever if there is no power supply.

If you live in a high-rise apartment building, gravity may not be sufficient to supply water to the entire building. As a result, these buildings generally use a pump to circulate water throughout the building. When the power goes out, the water cannot be circulated through the building. As a result, you will not be able to flush your toilet in the usual way.

How To Flush Toilet When Water Flow Is Stopped

If there is no water flow to your toilet and you do not have a septic tank system that requires a pump to empty it, you can use manual methods to flush your toilet.

This will require that you obtain water from another source, such as a swimming pool or pre-filled bathtub. You must fill it manually because the toilet’s tank will not refill automatically when there is no water supply.

bathtub with water

Simply open the toilet tank’s lid and fill it up before depressing the flush lever. Alternatively, you can quickly pour a gallon of water directly into the toilet’s bowl to flush it. This method may create a certain amount of splashback as you will have to pour the water in with force to help create an adequate amount of pressure.


While some people will be unaffected in their ability to flush the toilet when the power is out, others will not be able to flush their toilets whatsoever. It depends on your sewer system, toilet type, and water supply type. These three factors will determine your toilet’s ability to flush during power outages.

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