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How To Stop An Overflow

How To Stop An Overflow

By Greater London Properties

An overflowing toilet can be a common problem in the home, but the good news is that preventing it from happening or stopping it in its tracks can be easy when you know the cause. There are various things that can lead to a toilet overflow including blocked vents, clogged pipes, and sewage issues. These are some potential causes of an overflowing toilet to be aware of to prevent water damage and plumbing issues in your home.

Clogged Pipes:

A clog in your toilet or in the nearby pipes will prevent the water from draining when you flush. Using too much toilet paper is the most common cause of these types of clogs. This is more common with older low-flow toilets that tend to clog easily and often require you to flush more than once. Thankfully, clogs can be fixed quite easily with a plunger. If you are struggling to remove the clog on your own, get in touch with Greater London Properties who can send a maintenance professional to help.

If you’re struggling to remove a clog from your toilet, you should shut off the water supply to prevent the problem from worsening. You can usually do this by finding and turning the stopcock, which is typically located underneath the kitchen sink. Protect your home by ensuring that the affected area is dried and disinfected thoroughly. A professional will need to check the property if you notice any dirty water or bad smells as a result of the overflow.

Clogged toilet bowls are the most common reasons for an overflowing toilet, and typically happen when something is flushed down the toilet that shouldn’t be. Waste, water, and toilet paper are the only objects that should be flushed down the toilet. Flushing items such as sanitary products, paper towels, wet wipes, nappies, and anything else can lead to a clog since they do not break down easily.


Blocked Vents:

Plumbing vents are vertical pipes that connect to all plumbing fixtures in the home. It allows air to enter the pipes to replace the air that goes down the drain when you flush the toilet. Usually, the outlet for this vent is located on the roof. If it clogs with debris such as leaves, the vent might stop draining or drain very slowly. Even if the toilet does not overflow, it might cause bad smells or bubbling sounds when you flush. If you suspect that this is the problem with your toilet, get in touch with Greater London Properties who will arrange to have a contractor sent to your property to clean the vent.

Sewage Problems:

Your home is connected to the main sewer line by pipes. In some cases, these pipes can become blocked, especially if you have trees in your garden. They can also become clogged by flushing objects such as paper towels or wet wipes down the toilet over time. Unfortunately, some cleaning products that are advertised as being safe to flush do not always break down quite as easily as toilet paper, which can lead to clogging and an overflowing toilet. When the sewage cannot drain correctly, it will work its way back up the plumbing and may re-enter through the toilet. If your toilet is still overflowing after you have switched off the water at the mains, it could be due to a blockage in the sewer pipes.

Plumbing Problems:

Finally, if you are struggling to stop an overflowing toilet with a plunger, there might be an issue with your toilet’s plumbing. The issue could be with a broken tank flat mechanism or with the flush handle. It is important to get in touch with Greater London Properties who will arrange for a plumber to check your toilet if you suspect that the overflow is due to broken plumbing.

What to Do When there is a Great Overflowing of Water from Your Toilet:

  1. Turn off the water: Firstly, switch off the water supply to your property using the stopcock. This can usually be found underneath the kitchen sink. Turning off the water supply will ensure that there is no water running to your toilet.
  2. Unblock the toilet: If you suspect that the overflow is the result of a clog, make sure that you are using a toilet plunger to unblock the toilet. A toilet plunger has a centre flange that creates a tight seal around the drain opening in the toilet. You can use petroleum jelly to coat the edges of the plunger to improve its effectiveness. Increase downward pressure and speed as you work to break the clog up.
  3. Cleaning: If the toilet has overflowed into your bathroom, clean carefully. Often, the water may be contaminated with dangerous bacteria, so it’s important to use the right cleaning products and protect your hands with rubber gloves while cleaning. If the bathroom has flooded quite seriously, professional cleaners may be required.

How to Stop Toilet Water Tank from Overflowing


To stop an overflow quickly remove the tank lid on the back of the toilet. Reach inside the tank and lift the float for the fill valve until you see the water in the bowl stop rising. The fill valve is attached to the largest object in the tank and uses a float on one end. You want to lift the float in order to seal the fill valve so that the water will stop rising and prevent overflow. 

 Saniflo toilets

Some toilets are fitted with a Saniflo Macerator Pump, which breaks up material and pumps water into the drains of the property. They are used when a toilets position is too far from the drain pipe-work for it to be plumbed in normally.

If you have a Saniflo toilet you should be able to see a box, where the pump is located and you will hear the pump working when you flush the toilet. This sound is completely normal, though if you notice it increasing in volume or the sound changes, you should contact your property manager as there may be a fault with the pump.

Everyday use

The most important thing to note with Saniflo toilets is that you cannot put anything other than small amounts of toilet paper down them. Any items other than toilet paper can break the macerator. It is expensive to replace Saniflo pumps and if they break down due to misuse, you will be charged for repair or replacement.


You can use normal toilet cleaning products in your Saniflo toilet, though you should never use drain unblocking products, as this will damage the rubber components within the unit.

To de-scale a Saniflo toilet you must purchase the branded de-scaling product from a Saniflo supplier (these can be sourced from an internet search engine).

For both de-scaling and general cleaning you should follow this procedure;

1.       Turn off the pump unit

2.       Pour a strong dose of descalant, bleach or toilet cleaner

3.       Flush the WC

4.       Leave to stand for 30 minutes

5.       Switch power back on to pump unit and flush WC

Hopefully this answers your question on How to stop an overflow.

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