When your sump pump fails it can mean a basement flooding and thousands of dollars in water damage. Sump pumps may seem like confusing machines but most pump problems can be attributed to a few common problems.
Our team of sump pump experts put together a list of the most common reasons for your pump to stop working. Keep reading to learn more about keeping your pump running properly!
In this guide we’ll take a look at the most common reasons for pump failure:
Broken Float Switch
The most common reason for a pump to fail is a broken or stuck float switch. When the float switch is not rising and falling correctly the motor does not run at the right time.
A broken float switch in the sump pump can cause the motor to activate when the water rises in the basin or not turn off after the pit draining – resulting in a burned-out motor.
Clogged Discharge Pipe
Always make sure to check the discharge pipe if you are experiencing sump failure. Many times the lines will be clogged with debris like leaves which will make it seem like the pump has failed as water fills up the sump pit. We recommend checking the sump pump’s drain lines during quarterly maintenance to keep pump failure to a minimum.
If you consistently notice a build-up in the discharge lines consider installing additional filters to prevent clogs in the discharge line.
Mechanical Damage
One of the most common reasons for a pump to fail is mechanical damage to the pump, check valve or float switch. Brands like Zoeller, Wayne and Superior Pumps are well made but can all be damaged if dropped or buy rocks that get past the filter.
The most common part to suffer mechanical damage is the float switch. Always make sure this piece is free from obstruction and can rise and fall with the water level.

Need a pump you can count on to keep your basement dry that does not cost a small fortune? We recommend the Zoeller M53 Mighty Mate!
Improper Installation
An improperly installed sump pump may work for a few hours but is subject to failing after extended use. Most sometimes are easy to install and maintain but if the float switch is set up incorrectly it will not work. We recommend testing your set up to make sure the float can rise and fall with the water level – if it is touching the side it might get stuck!
Make sure that your sump pit and the motor are big enough for your home’s water flow. Using too small of a pump or basin can cause an overflow when water comes in faster than the pump can push it out the discharge pipe.
No Backup Battery or Pump
Not installing a back up battery and pump may seem like a smart way to save some money but you may find a flooded basement during a power outage. Even the best pump will fail from time to time or there will be power failures so it is important to be prepared to drain the inflow of water into your basement.
Lack of Maintenance
The most common cause of pump failure is not parts failing but lack of regular maintenance. Sump pumps take a lot of wear and tear and need quarterly maintenance in order to keep working their best. If the pump and basin have not been cleaned recently the pump may be failing due to a blockage or maintenance problem.
Extended Electrical Outage
Power outages and electrical problems in basements are another common cause of sump pump failures. If a tree limb falls and the power goes out to your home you will need a back up battery or water powered pump in order to keep draining the water.
In older homes with poorly installed wiring you may also face electrical problems. Some pumps use a lot of power when they are running and may be tripping your breaker and overloading your lines.
Frequently Asked Questions
What happens if your sump pump fails?
When your sump pump fails it will stop working and if you do not have a back up battery or a water powered pump your basin will begin to fill up and eventually overflow.
How do I know if my sump pump is failing?
You can tell if your sump pump is about to fail if it seems to be running more than normal, pushing less water, or over heating.