What is a Sump Pump and How Do Sump Pumps Work?

Technician installing sump pump

May 16, 2019


You’ve probably heard of sump pumps before. They are often mentioned by people after severe flooding or heavy storms. Sump Pumps are a vital part of the basement waterproofing system and in this article, we will explain not only what a sump pump is and how it works? but also answer the most frequently asked questions by our customers.

What Is A Sump Pump?

A sump pump is a pump that is used to remove water that accumulates in a water-collecting sump basin.  They’re commonly found in basements that are below the water table.

Water entering a home, due to heavy rain or high water table levels, is collected through the perimeter drains of a basement waterproofing system. The drains will funnel the water into the sump basin and the pump will then remove the collected water to the nearest drainage point.

Sump pumps are usually made of metal or plastic and are commonly submersed inside the chamber. The job of a sump pump is to direct water away from the house, to a place where it is no longer problematic, because of this, the pump will often be used in the basement of homes or areas where the water table is above the foundation level.

It is very easy for groundwater to collect in basements and crawl spaces. It will rise through cracks in your foundations and penetrate through your walls, often during long periods of rain or heavy storms.

If there is a possibility of flooding in your home, it is recommended that you have a sump pump installed. When the water level inside the chamber reaches a certain level, the pump will turn on automatically and drain the water away to a convenient drain off point.

Some pumps also have an alarm to let you know when the water level is too high. Other pumps come with a battery back-up system so they can work in the event of power failure.

How Does A Sump Pump Work?

A sump pump will be installed in the lowest part of your basement where a hole around 2 feet deep and 18 inches across is cut into your concrete floor and the pump is placed in the sump pit, also known as a sump basin.

The water will flow into the sump pit where it will be collected until the pump is activated.

A sump pump is activated by a float, similar to the one in your toilet tank, when the float rises to a set level the pump will start and the water will be pumped out of the sump basin.

The water is then taken by the pipes out of the home via a drainage point and safely discarded several feet away from the foundation of the property.

Sump pumps work really well when there is heavy rainfall, strong storms or rapidly melting snow. Instead of these weather elements flooding your home, they will be collected in the sump pit and pumped to a safe drainage area.

Choosing a Sump Pump

There are many different options for choosing a sump pump but when looking to choose which one there are a number of choices you will need to make before making your decision:

Manual or Automatic Pump

The automatic pump is predominately what most people have installed as it is more convenient than a manual pump.

The Amount of Horsepower

There needs to be a right balance of the amount of horsepower the sump pump needs to be able to deal with any potential basement flooding that could occur.

If there is too little horsepower for the motor to pump out the water, then flooding is going to be a problem. The sump pump system will not be able to deal with large amounts of water efficiently.

If the horsepower for the motor is too high, then it can run the risk of burning out. The recommended choice for a sump pump is between one-quarter to one-third horsepower.

Head Pressure

The head pressure should also be considered during the decision making process for choosing a sump pump. The head pressure is also known as the height at which the pumped water can rise to. The sump pump must allow the water to rise out of the chamber and then into the discharge pipe.

Back up and Alarm Systems

Sump pumps can stop working during a power cut, so you need a make sure that there is a battery backup system in place. A sump pump alarm is a useful attachment to let you know when the water level is rising too fast, and the property is at risk of flooding.

What are the Different Types of Sump Pumps?

There are two main types of sump pumps and these are the pedestal sump pump and a submersible sump pump. These are both designed to pump water out of the basement to prevent risk of flooding.

Pedestal Pump

The pedestal sump pump is often the more economical sump pump option. As it is mounted above the sump with an exposed motor it makes it easier for repairs to take place if needed.

The pedestal sump pump is the more visible pump, but often won’t last as long as the submersible sump pumps. There are also issues that pedestal pumps are noisy and more than likely going to overheat due to the motor being exposed.

Submersible Pump

The submersible pump is completely mounted inside the sump and sealed. This makes it the more visually appealing sump pump, but it does mean it is tricky to complete repairs if needed.

The submersible sump pump will tend to cost more than the pedestal sump pump. However, due to the motor being placed inside of the sump basin, it will last longer, be less obtrusive and quieter too.

It is important to note when choosing one of these primary sump pumps make sure you consider the following:

  • Sump pump alarm
  • Sump cover
  • The addition of a battery backup sump pump

Battery Backup Sump Pumps

Sump pumps are powered by electricity which means that when there is a power outage, for example during a storm, that the sump pump will stop working. This is when you want the pump to work the most.

Having a battery backup pump will provide you with the extra reassurance that even when there is no mains power the sump pump will continue to work.

The way that backup sump pumps work is that when the water starts to rise in the sump chamber and the main pump does not work for whatever reason then the battery backup pump will turn on automatically. The battery backup pump will then start to pump the water out of the property.

Do I Need a Sump pump in My Basement?

Depending on where your property is located your basement may not need a sump pump installed. If your basement has never suffered from standing water and it is warm and dry on a regular basis then a sump pump would not necessarily be needed.

If your house suffers from floods or it is damp or smells musty then it is more than likely that your property is suffering from moisture finding its way through into the basement.

Working alongside waterproofing solutions, having a sump pump in your basement will not only provide you with that extra protection from flooding, but also make sure that it is a dry, habitable living space.

What To Do If My Sump Pump Alarm Goes Off?

In the event of your alarm sounding, don’t panic! Sometimes condensation will make contact with the sensor inside the chamber and set off your alarm.

To find out if the water level inside your pump is too high, then listen to see if your pump is running constantly. It will sound similar to a dishwasher. The pump may be continuously running for various reasons, most of which can be easily fixed.

If you require an engineer to carry out sump pump repair then give us a call on 0800 019 9949 and we will endeavour to get someone out to help you as soon as possible.

How Long Do Sump Pumps Last?

Submersible sump pumps generally last up to 10 years if not longer. Regular service will ensure your pump lasts as long as possible. As submersible pumps can be expensive to replace, it will be cheaper for you in the long run to prolong the life of your sump pump.

However, it is always worthwhile checking with the manufacturer of your pump to find out how long they advise the manufacturer’s warranty is valid for.

How Long Can a Sump Pump Run For Continuously?

A good quality sump pump can run for an average of 20-24 hours straight and a low quality sump pump can run between 6 to 18 hours.

Sump pumps should not run continuously for a long period of time and if it does then there is cause for concern. If the sump pump runs for too long, then this can lead to them burning out.

Make sure if the sump pump has been running for over 24 hours, that it is checked out for any problems. The problems can range from having a frozen or clogged drain line to a dirty sump pit.

We would recommend having a qualified engineer come out and inspect your basement sump pump system. They can then assess whether the sump pump needs repairing, cleaning or a replacement installation.

Why Do I Need My Sump Pump Serviced?

Once your sump pump is installed, it’s easy to forget it is even there. Many people only become aware that they have a sump pump fitted if suddenly their basement starts to flood. Flooding can occur if your pump has broken, if the pump isn’t powerful enough or if there is a blockage in your perimeter channel.

An annual service may be required to validate any insurance or guarantee on your basement in the event of a flood and to avoid any loss of personal property that may be housed near your pump. Regular maintenance is recommended to ensure your pump is functioning properly.

How Often Should I Get My Sump Pump Serviced?

To keep your sump pump in good working condition, we recommend having a service every 12 months. However, some pumps are used more frequently than others.

For example: We attend many pumps in London that are heavily used due to a build-up of silt in their basement drainage channels, so in such instances, we would recommend a service every 6 months to ensure the pump is working as it should. The Basement Sump Pump Company can offer competitive discounts to customers who require a service every 6 months.

Your pump will also be heavily used if it disposes of water from a washing machine or dishwasher. We also service sewage pumps, which may require a deep clean every other year. This can be assessed at the time of your pump service.

Why Do You Need A Sump Pump?

If you have a beautifully finished basement that is nicely converted into the perfect space to relax and unwind with gorgeous carpets, the latest electronics and more, then you definitely need a sump pump installed.

It will help avoid the risk of bad weather, or a change in water table levels, destroying your dream basement space.

You should also be considering a sump pump repair if your basement has flooded before. If you live in a flat or low lying area with soil that readily and easily traps water.

If you live somewhere that has lots of extreme weather such as frequent heavy rain or snow or if your existing pump is 6 years old or more as they will usually last up to 10 years.

In order to get the most out of your pump, it is vitally important that they receive a regular service to keep them working efficiently and prevent any unwanted buildup.

If you would like a basement sump pump servicing then get in touch with us by calling 0800 019 9949 or contact us online.

Contact Us Online


  1. Wil Lenton

    Hi There,
    Could you please give estimate for installation of a cellar sump pump, in order to keep cellar dry.

    The cellar size is approx 3.27M x 2.77M

  2. Rob

    Hi Wil,

    Thank you for getting in touch with The Basement Sump and Pump Company. If you could send your contact details to info@basementcare.co.uk our customer services team will be touch to provide you an estimate for installing a cellar sump pump.


    The Basement Sump and Pump Company

  3. Tom

    My town house is Victorian era and has three floors. We have been doing some work in the lower ground floor and discover water under the floorboards and wooden beams. This accumulates when it rains and then drains away but it has been in contact with the wood so we need to replace them and install a sump and pump. As this is a raised floor with wooden beams do we have to install a DPC and concrete over or can we just dig a channel and install a sump and pump. Drainage for the pump is easy as there are storm drains on the lower ground floor.

  4. Rob

    Hi Tom, Thank you for getting in touch with The Basement Sump and Pump Company. If you could send your contact details to info@basementcare.co.uk our customer services team will be touch to go through what the best option would be.


    The Basement Sump and Pump Company

  5. Christopher Juden

    Due to a steeply sloping site there is already 1.3m headroom under the floor on one side of my house. So I propose to underpin the ridiculously shallow foundations of the downhill wall and create a cellar utility room. The floor, unfortunately , will be 20-40cm below the invert of the drains, so I’ll have to pump the waste from a sink and washing machine up to some higher point in the soil stack, before it can go down them. Can I direct this waste to a sump and have the one pump take care of both this and any damp problems? Note: the drains here already carry rainwater in addition to waste and there is no risk of flooding. (Don’t really need a sump pump, could simply run a land drain a few metres further down the 1:5 hill!)

  6. Yasmin Naqushbandi

    What is the life time of a sump pump ?

  7. Rob

    The lifetime for a sump pump is up to 10 years.

  8. Hugo van der Meer

    Hallo. Just enquiring whether your service is country wide or whether you only operate within a specific geographical location. I’m in Derbyshire.

    Many thanks.

  9. Rob

    Hi Hugo, Thank you for getting in touch. We are a nationwide company and we cover the Derbyshire area. If you contact our team online, email us at info@basmentsumpandpump.co.uk or call us on 0800 019 9949.

  10. Ayden

    Thanks for the info, i couldnt find another posts to even come close to explaining this for me, thanks!

  11. Denise

    Hi, please can you tell me if you cover West Yorkshire. I live in Huddersfield and would like to have my sump pump serviced. If so please could I have a quote. Thankyou.

  12. Basement Carer

    Hi Denise, we do cover West Yorkshire – if you give the team a call on 0800 019 9949 we’ll be able to help you further.

Submit a Comment

Your email address will not be published. Required fields are marked *