Downspout Not Draining? Here's How to Fix It
Last updated: May 23, 2026 · Reading time ~5 min
The tap test
From the top, tap the downspout face every 12 inches with a hammer handle or screwdriver. Hollow knock = clear. Solid thunk = clogged section. Clog is at the lowest hollow point.
Clearing techniques
Top of downspout: Garden hose at full blast pushed into the drop outlet. Flushes most clogs.
Middle elbow: Pressure-wash the downspout from below (turn upward) with a flexible extension. Or disassemble the elbow.
Bottom extension: Easiest — disconnect the extension at ground level, snake out debris.
Prevention
Most downspout clogs start as gutter leaf piles that slip into the drop outlet. Gutter guards (especially LeafBlaster Pro) eliminate 90%+ of downspout clogs.
Frequently asked
Can I use a plumber's snake?
Yes — a 25-foot drum snake works well in 2x3 and 3x4 downspouts.
What if pressure washer doesn't clear it?
Disassemble the elbow. Most downspouts unscrew or pop apart with mild force.
Should I add a downspout cleanout?
Not standard on residential. Some commercial systems use them.
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