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Sump Pump Making Noise: Clanging, Gurgling, Grinding and What to Do
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What the sound may mean
| Sound | Likely cause (source) | What the source says to try |
|---|---|---|
| Clanging or banging | The discharge pipe hits the pump basin (Ann Arbor). | Wrap insulation around the pipe where it touches the basin or wall. Line the underside of the lid with rubber grommets. Have a certified plumber reroute a line with many angles and joints. |
| Gurgling | Water flows back down the discharge pipe after the pump cycles (Ann Arbor). | Swap a swing check valve for a spring-loaded one. Set the switch so the pump stops before the pit is fully empty. Cover the pit with a lid or fitted foam insulation. |
| Loud air noise when it starts | Air is moved out of the pipe as water moves through it. Older, lower-quality pumps are louder (Ann Arbor). | Ann Arbor says higher-quality pumps are quieter. It lists pump design, location in the pit, condition and materials as factors. |
| Rattling or vibration | Pipe striking the pump or lid (Ann Arbor). | Rubber grommets reduce vibration and motor rattling. |
| Sounds like pumping gravel; sluggish float | Worn pump or float (NDSU Extension). NDSU lists damaged or rusted motor bearings as a common cause of failure. | NDSU says you may need a new pump or float. |
| Struggling or irregular sound | SDSU says this may mean the pump is reaching the end of its usable life. | Check and fix it before it fails, says SDSU. |
Sources: City of Ann Arbor, SDSU Extension, NDSU Extension. We found no source that matches every possible sound to a cause.
Steps
- Listen while it runs. SDSU says to listen for anything strange. Note whether the sound happens at start, during pumping or when the pump shuts off.
- Unplug the pump before you touch anything. Ann Arbor and SDSU both say to unplug first.
- Look for loose parts. Check whether the discharge pipe touches the basin or wall, and whether debris is near the float or impeller. Ann Arbor says debris in the impeller or a broken impeller can overheat the casing.
- Try the quiet-down fixes above: insulation, rubber grommets, a spring-loaded check valve, or a lid.
- Call a licensed plumber if the noise is grinding, gets worse or the pump does not shut off. Ann Arbor says most plumbers can repair or replace sump pumps.
Not sure if it is failing? See sump pump not working: signs and repair. If the pump needs replacing, see our replacement guide.
A noisy pump may be an old one. Have a backup ready.
A backup keeps the basement dry when the power goes out or the main pump fails. Read the pros and cons of battery, water-powered and generator options first.
Battery vs water-powered backupBrowse battery backup pumpsCommon questions
Is it normal for a sump pump to make noise?
Some noise is normal. Ann Arbor says sump pumps are mechanical systems and make noise when they run, and that as water moves through the pipe it first moves air out. Older, lower-quality pumps may make a lot of noise when air is released.
Why does my sump pump make a clanging sound?
Ann Arbor says clanging is caused by the discharge pipe hitting the pump's basin. Wrapping insulation around the pipe where it touches the basin or wall may reduce it. Excessive angles and joints in the discharge line can also cause clanging and vibration, and a certified plumber can reroute the line.
Why does my sump pump gurgle?
Ann Arbor says gurgling is often caused when water flows back down the discharge pipe after the pump cycles. A spring-loaded check valve instead of a standard swing check valve may reduce it. Adjusting the switch so the pump stops before the pit is completely empty can also help, because an empty pit makes a sound like sucking liquid through a straw.
What if it sounds like it is pumping gravel?
NDSU Extension says that if the pump sounds like it is pumping gravel or the float is sluggish, you may need a new pump or float. SDSU Extension says to listen for anything strange as the pump runs, and that a pump that struggles or sounds irregular may be reaching the end of its usable life.
When should I replace a noisy pump?
Ann Arbor says that if the motor is very noisy, the system is old and you have already tried rubber stoppers, it may be time to replace the system. It says plastic or PVC pumps are noisier than cast-iron ones and newer pumps with self-lubricating motors run more quietly.
Related guides
- Sump pump not working: signs and repair
- Replacement and installation
- Why does my sump pump run every 5 minutes?
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