Potomac homes, with a median build year of 1977, often have large finished basements where a failed sump pump can do real damage quickly. Common causes are a stuck float, a failed check valve, a clogged intake or a discharge line that is frozen or crushed. Call the number on this page to be connected with a local plumber in Potomac.

Potomac grew from a farming community into an affluent suburb, and its housing mixes older farmhouses with subdivisions built around the 1970s. Most homes are on WSSC Water's public water and sewer, but Montgomery County assigns every property a water and sewer category, and some parcels are designated for private wells and onsite wastewater systems. That matters for where pump water can go and what a backup pump can tie into.
What to do right now
- Shut off power to basement circuits near standing water.
- Reset the GFCI outlet the pump plugs into and listen for the motor.
- Free the float if it is snagged on the basin wall or the power cord.
- Follow the discharge outside and clear snow, ice, leaves or a crushed end.
- If your home is on a private onsite wastewater system, limit water use until the cause is clear.
- Get furniture, rugs and stored items off the floor.
Symptoms and likely causes
| Symptom | Likely cause |
|---|---|
| Pump will not start | Tripped GFCI, dead switch or motor failure |
| Runs without stopping | Float stuck up, inflow beyond the pump's capacity |
| Water drops back into the pit | Failed check valve |
| Wet walls but dry pit | Drain tile clogged or no path to the basin |
| Ice at the discharge outlet | Line holding water in freezing weather |
| Grinding or rattling | Debris in the impeller or worn bearings |
Cost factors
- Pump size and whether a dual-pump setup is warranted for a large basement
- Part repair versus full replacement
- Long discharge runs across a big lot, including trenching
- Battery backup, which avoids tying into the water supply
- Water-powered backup, which needs backflow protection that WSSC requires testing on every year if it is a testable assembly
- Permits through WSSC Water Permit Services when piping changes
Homes with irrigation systems already have a testable backflow assembly that needs a yearly spring test under WSSC's cross-connection program; a plumber can often check the sump on the same visit.
When you call, the number connects you with an independent plumber who works in Potomac. Say whether water is rising now, whether your property is on public sewer or a private system, and whether the basement is finished. If you are not sure of your water and sewer category, your bill or the county can tell you, and it helps the plumber plan where new discharge piping can go.
Sump Pumps questions in Potomac
Can a sump pump empty into a private onsite wastewater system?
Does a water-powered backup pump need backflow protection?
Where should the discharge line end up?
Should I repair my old pump or replace it?
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