Collapsing building © Daniel Friedman Toilet overflow emergency: what to do
How to stop an overflowing toilet

  • TOILET OVERFLOW EMERGENCY - CONTENTS: how to stop an overflowing toilet & what to do about cleaning up sewage spills from a toilet overflow. First aid for toilet problems - how to keep a toilet from overflowing or how to stop an overflowing toilet. How to respond to backing up drains or overflowing toilets - emergency toilet repair guide. How to prevent a septic or sewer system backup during heavy use of a private septic tank and system.
  • POST a QUESTION or READ FAQs about how to stop an overflowing toilet & what to do about cleaning up sewage spills from a toilet overflow
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How to stop a toilet from overflowing: this article describes simple and quick steps you can take to stop an overflowing toilet or a toilet whose bowl is filling and that is about to overflow. Our unpleasant page top photo illustrates the problem with which you may be confronted, often alone, perhaps just after having used the toilet.

Here we explain that quickly lifting the toilet tank lid and taking one or two simple steps can avoid a messy toilet overflow catastrophe.

We also explain how to prevent a septic or sewer system backup during heavy use of a private septic tank and system.

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Emergency Toilet Overflow Rescue Procedure - how to stop a toilet from overflowing

Toilet with tank lid on seatIf the toilet is about to overflow here is what you do to prevent sewage from running over the toilet bowl and onto the floor:

Take off the toilet tank lid - Quickly but carefully
, remove the lid from the toilet tank and set it aside.

You can place the toilet tank lid right across the toilet bowl.

Don't knock the lid on the floor - they break.

Don't waste time moving towels and stuff - we're in a rush to stop the toilet from overflowing.

Toilet flush valve being pushed shutReach inside the toilet and push down the flapper valve that is letting the tank empty water into the toilet bowl - this will stop water from entering the toilet and if you're quick enough, prevent sewage from overflowing onto the floor.

This will be a rubber valve in the center of the bottom of the toilet tank.

This will stop water from flowing from the toilet tank into the toilet bowl.

Don't be afraid to touch the water in the toilet tank - it's sanitary.



Toilet fill valve held shut
Stop the toilet & its tank from further filling by lifting up the float
that operates the toilet tank fill valve.

This will stop water from entering the toilet tank from the toilet supply line.

The photo shows that water is stopped and the flapper in the toilet tank bottom is shut.


If the water level in the toilet bowl is dropping slowly, keep holding the toilet tank float up in its highest position so that water stops flowing into the tank and into the toilet bowl.

Wait a minute - if in the next minute or two the water level in the toilet bowl slowly drops down to a normal level, you'll be able to release the toilet tank float and let the tank and toilet bowl refill without danger of overflowing onto the floor.

Closing the toilet fill valve
If the water level in the toilet tank is not dropping,
after a minute or until you can't bear standing there any longer, continue to hold up the toilet tank float while you close the toilet supply valve near the floor or in the wall behind the toilet.

Still holding up the float so that the toilet tank stops filling, reach down and carefully turn off the toilet fill valve. Turn the handle clockwise to close the valve.

If you can't do both, let the float drop and quickly close the valve.

If the toilet supply valve is hard to turn do not force it - it could break and give a terrible supply leak on top of your blocked drain problems.

Toilet bowl fill tube connected normally
If you cannot close the toilet fill valve, or if there isn't one
, remove the little flexible rubber or plastic tube that is sending water into the toilet bowl through the vertical standpipe.

The photo at left shows this tube in its normal position and you can see it shooting water into the toilet bowl refill tube.

The standpipe also supports the flapper valve but the water squirting into the tube is going right into the toilet bowl.

Toilet bowl fill tube disconnected
Aim the flexible little bowl-fill tube into the toilet tank instead.

Now you can let the float drop and let the toilet tank fill.

The reason for this step is that that little tube is sending extra water into the toilet bowl even when the main toilet tank flapper valve has shut.

You're trying to avoid filling and overflowing the toilet tank.

The photo shows us directing the bowl-fill tube water into the toile tank instead.

Once the toilet tank has filled you can clip this tube back in place where as shown in the photo before this one.

OK so You Prevented the Toilet From Overflowing onto the Floor, What Next:

  • Stop using all toilets and fixtures: stop running water in sinks and showers etc. while you investigate.
  • Try using a toilet plunger to see if you can clear a blocked drain. Don't splash sewage all over yourself, or if you do, wash carefully afterwards. Don't give up too soon. Sometimes repeated plunging for a minute will remove a blockage in a house drain. If during plunging the toilet you see sewage coming up in a nearby tub drain, close the tub drain and try again.
  • Investigate the problem to find out the probable cause. Check all of the bathrooms and all plumbing fixtures, starting with the fixtures lowest in the building.
  • When checking upper floor fixtures have an accomplice keep an eye on the lower floor toilets and drains - otherwise you may think that upstairs drains are working when in fact they're simply backing up out of the lower floor toilets.

    See Backups and Clogged Drains diagnosing septic backups and septic system failures versus clogged drains - for details on how to diagnose blocked drains and septic or sewage backups.
  • If only one drain or toilet is blocked, is there another bathroom that's working? If so you may have just a local problem and you can survive by not using the problem toilet.
  • If all of the toilets or drains are backing up or slow, you may have a blocked system drain or a flooded failing septic field. If so you will have to stop using toilets and sinks indoors. It's possible that after letting the drainfield rest for an hour or so you may be able to return to modest use of toilets. Meanwhile do not run any water into any drains if you can avoid it.
  • If your home is connected to a private septic tank, look outside at the septic fields: do you see evidence of septic effluent at the surface? If so, no amount of plunging will correct the problem.
  • If your home is connected to a municipal sewer, you may have a blocked main drain.
  • If your home uses a sewage ejector pump or septic pump, check that the pump has electrical power, is turned on, and is working. See Pumps Septic pumps, sewage ejector pumps, grinder pumps, effluent pumps, sump pumps, & septic pumping stations compared; pump alarms. Advice.
  • Call a plumber to try clearing a blocked drain and or ...
Photo of septic tank being pumped
  • Call a septic pumping company to ask for an emergency pump out.

    This won't fix a broken septic system but if the problem is indeed a flooded drainfield, the empty septic tank will permit your guests to use bathrooms as needed during the event in your home.

  • Porta potti
    Use a portable or chemical toilet: Call a port-a-john portable toilet company, if all else fails and you have lots of guests who will be in the building over an extended time.

    You can rent one or more portable toilets.

    In a pinch you may be able to borrow a camping toilet or chemical toilet like this Thetford porta-potty from someone who has that device.

If you have had sewage back up and spill out of toilets into the building, cleanup is needed and you may face bacterial hazards. See SEWAGE CONTAMINATION in BUILDINGS for advice.

Why Does the Septic or Sewer System Back Up During a Party?

Sewage backup into bathtub
Indeed it seems to be just the luck that we are living happily along not giving the septic tank a thought until we have a bunch of guests over for Thanksgiving, Chanukah, Christmas, or a graduation party. Why is it that at events we often see the septic system backing up?

The photo shows sewage water backing up into a bath tub. This is what can happen at bottom floor fixtures in a home when the main drain is blocked or the septic system is blocked and you keep flushing toilets or running fixtures at upper floors. Don't do this.

Septic systems seem to fail during a party because the septic system was already in trouble, but our usage was modest enough that we just weren't noticing it.

The surge of waste water entering the septic tank cannot flow into a flooded drainfield so sewage may back up into the home, usually at the lowest plumbing fixture. Sometimes it's not the wastewater surge but someone flushing something down a toilet that blocks a drain - that's a problem that can be cleared by a plumber using a plumbing snake or drain router. But often the problem is in the septic field itself.

Readers should see CAMPING & EMERGENCY TOILETS and also see ALTERNATIVE & WATERLESS TOILETS for a discussion of camping toilets, chemical toilets, emergency-use toilets, waterless toilets, graywater systems, composting toilets, home health care toilets, incinerating toilets, outhouses, and latrines.


Continue reading at TOILET REPAIR GUIDE or select a topic from the More Reading links shown below.

Or see BLOCKED DRAIN REPAIR METHODS to try clearing your blocked drain before going to more drastic measures.

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TOILET OVERFLOW EMERGENCY at - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

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