How to Test Your Sump Pump Before the Wet Season

A sump pump is one of those pieces of equipment homeowners forget about almost by design. It lives in a pit, usually in a basement or crawl space, and does nothing at all for months at a time. That's the point — it's only supposed to work when groundwater rises enough to need it. The problem is that "does nothing for months" and "has quietly failed" look identical from the outside. The only way to tell the difference is to test it before you need it, not during the storm that does.

Here's how to do that in about ten minutes, before the Puget Sound wet season settles in for good.

Why this matters more here than it sounds like it should

Seattle-area homes don't flood the way homes in flatter, lower-lying regions do, but plenty of basements and crawl spaces sit close enough to the water table that a sump pump is doing real work every wet season — carrying groundwater and drainage runoff away from the foundation before it becomes standing water indoors. When that pump is working, you never think about it. When it isn't, you usually find out at the worst possible time: during a heavy rain event, when the water table is already high and every other pump in the neighborhood is under the same load.

Testing it now, while it's dry outside and you're not standing in an emergency, is the entire strategy.

What you'll need

• A bucket of water (a few gallons is usually enough)
• A flashlight
• Ten minutes

No specialized tools. This is a check anyone can do, regardless of plumbing experience.

Step-by-step: testing a standard sump pump

1. Find the pump and clear the pit. Locate the sump pit — usually a covered basin in the lowest part of a basement or crawl space. Remove any debris, dirt, or built-up sediment sitting in the pit or around the pump's intake screen. A pump can be mechanically fine and still fail to move water if the intake is clogged.

2. Check the power connection. Confirm the pump is plugged directly into an outlet (not daisy-chained through other equipment) and that the outlet is working. If your setup includes a dedicated circuit or a GFCI outlet, make sure it hasn't tripped.

3. Inspect the float switch. Most sump pumps use a float that rises with the water level and triggers the pump. Make sure the float moves freely and isn't wedged against the side of the pit, tangled in the cord, or stuck in a position that would prevent it from rising.

4. Pour water into the pit. Slowly pour your bucket of water in until the water level rises enough to lift the float. You're simulating what happens during an actual groundwater rise.

5. Listen and watch for the pump to activate. A working pump should kick on within a few seconds of the float rising, and you should hear it moving water. If it activates, watch it run through a full cycle — it should pump the water down until the float drops and the pump shuts off on its own.

6. Confirm the discharge line is actually moving water outside. This step gets skipped more than any other, and it's the one that matters most. Go outside and check the discharge point — the pump can run perfectly and still fail the job if the discharge line is frozen, clogged, disconnected, or draining right back toward the foundation instead of away from it.

7. Check the backup power situation, if you have one. Some sump pump setups include a battery backup for power outages — which matter here, since heavy PNW storms that raise the water table are often the same storms that knock out power. If you have a backup system, confirm it's charged and test it separately if the unit allows it.

What a failed test looks like

• Nothing happens when the float rises. Could be a power issue, a stuck float, or a pump that's seized. Any of these means the pump won't help you when it counts.
• The pump runs but doesn't move much water, or runs continuously without the level dropping. This usually points to a clogged intake, a failing impeller, or a pump that's undersized or worn out for the volume it's handling.
• Water comes out the discharge line but pools right back near the foundation. The pump isn't the problem — the discharge routing is. This is a drainage fix, not a pump fix.
• The pump activates but sounds labored, grinds, or cycles on and off rapidly. These are signs of a pump nearing the end of its service life, even if it's technically still working today.

None of these need to be diagnosed with certainty on your own. What matters is recognizing that something's off while you still have time to address it, instead of finding out mid-storm.

How often to do this

Once before the wet season starts is the minimum. If your home has a history of a high water table, a previous flooding event, or a sump pump that's more than a few years old, it's worth repeating this check partway through the wet season too — pumps that run frequently under heavy load wear out faster than ones that rarely activate.

If the test doesn't go well

A sump pump that fails its test now is a maintenance item. A sump pump that fails silently during a storm is a flooded basement or crawl space, and the difference between those two outcomes is entirely a matter of timing. If your pump didn't activate, isn't discharging water properly, or sounds like it's struggling, it's worth having someone look at it before the rain arrives — not after water is already sitting where it shouldn't be.

And if you're reading this after the fact, because water already found its way in, that's a different problem with a different fix. Our water damage restoration team handles exactly that kind of emergency across the Puget Sound region.

Get in touch or call (425) 999-1091 if you want your sump pump checked properly before the wet season, or if you're already dealing with water where it doesn't belong.