Sump pump maintenance checklist - spring and fall, 20 minutes.

Master plumber, Dillsburg, PA. Updated April 2026. Sump pumps are the only thing standing between your basement and the water table during a heavy spring rain in Central PA. Most pumps that fail in a flood failed silently months earlier. Here's the 20-minute check we do at every basement we visit.

Photo by Sanket Mishra on Unsplash

When to run this checklist

• March - before spring rains and snowmelt.
• October - before fall storms and winter freeze-ups.
• After any major weather event - even if the pump appeared to work fine.
• If the alarm tripped at any point in the past year.

Primary pump check

1. Visual. Lift the lid. Look for sediment, gravel, or debris in the basin. A pump pulling debris is a pump on borrowed time.
2. Float test. Lift the float manually (gloved hand). The pump should turn on within 1 second. If it hesitates or hums, the bearings are going.
3. Bucket test. Pour 5 gallons in slowly. The pump should activate, run smoothly, and shut off within 30 seconds of the basin emptying. Listen for grinding or rattling.
4. GFCI test. If your pump is on a GFCI outlet (older code, not current), trip and reset it to confirm it still works. Many sump pumps fail because the GFCI tripped silently weeks ago.
5. Power cord. Make sure it's plugged in directly to a dedicated outlet, not through an extension cord or surge strip.

Battery backup check

1. Battery condition. Most backup systems have a status LED. Solid green is good. Flashing or red means battery is at end of life - replace at year 3 to 5.
2. Backup test. Unplug the primary pump's power. Then pour 5 gallons into the basin. The backup should activate. If it doesn't, the battery is dead OR the float on the backup pump is stuck.
3. Distilled water (lead acid only). Top up cells if your battery is the wet-cell type. AGM and sealed batteries don't need this.
4. Alarm test. Use the test button. The high-water alarm should sound. Replace the 9V battery in the alarm head.

Discharge line check

Outside the house, find the discharge pipe outlet. Make sure:

• It's clear of leaves, mulch, and ice.
• It points at least 6 to 10 feet away from the foundation.
• The freeze-protection guard or air gap (typically a 1/8" hole near the inlet) is not blocked.
• No backflow from a low spot in the yard.

Once-a-year deeper service

Once a year, in addition to the seasonal checks above:

• Pull the pump entirely. Clean the basin (vacuum if shop-vac is rated for water).
• Check the impeller for trapped debris.
• Inspect the check valve. A leaking check valve makes the pump cycle every few minutes - it's a major reason pumps fail early.
• Check pipe joints for cracks or weeping.
• Confirm the dedicated 15-amp circuit is not shared with anything else.

Sump pump FAQs

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