Sump Pump Troubleshooting
For homeowners, maintaining a sump pump is important to protecting property from damage caused by flooding. When maintaining a sump pump, some troubleshooting and/or testing may be required to identify potential issues.
Here are some common symptoms, possible causes, and corrective actions for maintaining a sump pump.
Symptom 1: Sump Pump will not Start
If your sump pump will not start, there are a few possible causes:
- The float switch is not being raised up high enough by the water level to trigger the pump to turn on.
- The pump is not receiving the right amount of electricity.
- The impeller is jammed with some kind of debris.
- The float switch is defective.
- The pump has shut down due to overheating.
- The pump is just bad and needs to be replaced.
Go down the list of possible causes to determine the problem with the pump.
Is it the Float Switch?
- Is the float ball stuck on something? If so, remove the obstacle or reposition the pump so that there is nothing in the way preventing the float switch from becoming engaged.
- Try raising the float by lifting it up by hand to see if the pump turns on, or add water to the sump basin until the float becomes activated.
Is it Getting Enough Electricity?
- First, check the outlet to make sure the pump is plugged in.
- Check the electrical outlet in your home by plugging something else in to see if the outlet is working properly or if you need to reset the breaker. Then try plugging the pump directly into the outlet without using an extension cord to rule out the possibility of a bad cord.
- Make sure you are using an extension cord that is heavy enough to support the horsepower of the pump.
- Make sure the wire that is providing power to the electrical outlet where the pump is plugged in is adequate for the amount of horsepower.
- Make sure the pump is plugged into an electrical outlet that is powered by its own circuit breaker or fuse. If not, you need to have a seperate outlet installed that is powered by its own breaker.
Is the Impeller Jammed?
- Unplug the pump from the power supply and remove the screen from the bottom of the pump. Look inside to check for debris. If you see that the impeller is blocked, carefully clean it out so that the impeller can rotate freely.
Is the Float Switch Defective?
- Try to bypass the float switch with a new float switch.
Has the Pump Overheated?
- Make sure you are only using the pump to remove water from a sump basin. Sump pumps are not designed to pump water in a pond or waterfall or operate for long periods of time. A fountain pump would be better for these types of applications.
- Make sure the pump is plugged into an outlet on its own circuit breaker or fuse. Low voltage can cause thermal overload, or overheating.
Is the Pump Just Bad?
- If all items above pass the test, then chances are you just need a new pump. Visit your local Tractor Supply Co. store to find a great selection of steel, cast-iron, or thermoplastic water pumps.
Symptom 2: Pump Motor Hums but Little or No Water is Ejected from Sump Basin
If your sump pump sounds like it's running, but you aren't seeing any water coming out, there are a few possible causes:
- The motor is just humming but not actually running.
- The pump is air-locked.
- The check valve is stuck closed or installed incorrectly.
- The impeller is damaged.
- The pump discharge pipe is partially or fully blocked.
- The sucction intake screen is partly or fully blocked.
- The volute, or bottom of the pump, is cracked and is allowing water to leak out.
- The discharge pipe is leaking.
Is the Motor Humming but not Running?
- See "Symptom 1: Sump Pump will not Start".
Is the Pump Air-Locked?
- Try drilling a 1/16" to 1/8" anti-airlock hole in the pipe just above the pump's discharge and just below the check valve.
Is the Check Valve Stuck, Closed, or Installed Incorrectly?
- Examine the check valve and make sure it is not stuck in a closed position.
- Look at the arrow on the existing check valve to make sure it is pointing in the right direction. This will tell you if the pump's check valve is installed correctly.
Is the Impeller Damaged?
- Examine the impeller to see if there are worn or missing blades, and replace the impeller if needed.
Is the Discharge Pipe Blocked?
- Examine the discharge area of the pipe to see if there is anything blocking it. Also check to see if the pipe is frozen.
- If your discharge pipe has too many 90 degree bends, then the water flow can be reduced significantly due to a lack of water pressure. More than three or four bends is too many. Consider replacing this plumbing with a more straight-forward pipe system that will allow for an easier flow of water out of the pump.
Is the Suction Intake Screen Blocked?
- Examine the intake screen at the bottom of the pump to make sure there is no debris blocking it. If so, remove the debris.
Is the Discharge Pipe Leaking?
- Examine the discharge pipe and pipe joints to make sure there are no leaks or places where water can leave the pipe and drip back down into the sump basin.