1 services · Seattle

Basements & sump pumps in Seattle, WA

A sump pump keeps groundwater from rising into a basement or crawl space. Most last about 7 to 10 years. Replacing an aging pump before storm season, and adding a battery backup or alarm, is far cheaper than cleaning up a flooded basement.

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Basements & sump pumps services in Seattle

Sump pump service in Seattle

Urgent

A sump pump that won't run usually has a stuck float switch or a failed motor. One that runs constantly may have a bad check valve or a high water table. In cold winters, a frozen discharge line outside is a common cause of a pump that runs but doesn't empty the pit.

Local conditions

Basements & sump pumps in Seattle: what's different

Seattle's Craftsman homes often have basements, and months of steady rain push water against foundations on hillside lots. Many older basements rely on a sump pump or foundation drains that were added long after the house was built.

Seattle Public Utilities handles drainage as well as sewer, but water that reaches a basement through the foundation or a floor drain is the owner's problem. Testing the pump before the rainy season and making sure discharge goes away from the house prevents most basement flooding.

Water and sewer in Seattle: Seattle Public Utilities provides water, sewer and drainage service.
Permits in Seattle: Plumbing and gas piping permits in Seattle are issued by Public Health – Seattle & King County; side sewer permits come from the City of Seattle.

Seattle housing and plumbing

Craftsman homes from the early 1900s in Ballard, Wallingford and Queen Anne often have basements, clay side sewers and galvanized supply.

Other Seattle conditions that affect plumbing

Side sewer repairs: Seattle homeowners own their side sewer to the main, and older clay lines often need repair.
Heavy rain: Wet winters test basements, drains and sump pumps.
Earthquake readiness: Water heater strapping and flexible connections reduce damage risk.
Rain and steep lots: Seattle's many hills mean side sewers run down steep yards, and long wet seasons saturate soil around older clay pipe.

Neighborhoods and ZIP codes

Plumbers on Thawline cover Seattle and King County, including Ballard, Capitol Hill, Queen Anne, Wallingford, West Seattle, Beacon Hill. ZIP codes: 98101 · 98102 · 98103 · 98104 · 98105 · 98106.

When to call a plumber in Seattle

The pump runs constantly or turns on and off rapidly
The pump hums but doesn't move water
Water in the basement after a storm
Rust, loud noise or a pump more than seven years old
No backup during storms that knock out power

How these problems start and how to choose between repair options is covered in the basements & sump pumps guide.

Basements & sump pumps questions in Seattle

When should Seattle homeowners test their sump pump?

In early fall, before the long rainy season begins. Pour water into the pit to confirm the pump starts, empties it and shuts off, and check that the discharge line is clear.

How do I test a sump pump?

Slowly pour a bucket of water into the pit. The pump should start, empty the pit and shut off. If it doesn't start, check that it's plugged in and the float can move freely.

More plumbing in Seattle

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