A gutter that does not drain properly may need an adjustment. After installation, gutter hangers and screws can fall out, leaving the gutter sagging. A gutter that sags and dips will not have the proper slope needed to allow water to travel into the downspout to be expelled. Standing water in a gutter system is unsanitary and unsafe. Stagnant water breeds mosquitoes and can cause rust in steel gutter systems, and improperly sloped gutters can cause clogs.
Inspect the gutter from the ground and from a ladder for signs of sagging, standing water and leaks.
Measure the distance between the bottom of the fascia board and the bottom of the gutter on the section of gutter farthest from the downspout.
Move the ladder 10 feet down the run of gutter. Mark the fascia board1/4 inch below the first measurement. Reposition the gutter with new hangers and screws, so that the gutter is sloped to rest on the mark made on the fascia board.
Continue down the run of gutter making sure that every 10 feet ends 1/4 inch lower than the previous section. Replace any missing screws and hangers.
Test the gutter with a garden hose to ensure that the water travels freely through the gutter into the downspout.