You should not see any large gaps between the gutters and their joiners. If you do they may need to be cut out and replaced immediately. 

Materials wear down over time. If you see any visible cracks or fractures. Water will find it's a way through to your home and foundation.

Water should move freely through your gutters to the downspouts. If you find standing water it may mean you have a blockage or an issue with the installation.

Gutters that are sagging or pulling away from your home may mean your brackets holding your gutters have been compromised and requires replacement immediately. 

Peeling paint is a sign of excess moisture. Exterior paint is designed to handle what nature throws at it. However, this can also be a sign that water from your gutters is finding it's way to your siding. 

Metal exposed to water will naturally create rust. If you're in an area with heavy rainfall you will see that rust begin to take hold and deteriorate your gutter system over time. 

If you find mold in your basement or near the top of your siding, it could indicate that your gutter system is not working properly.

Its time for a free inspection. 

Shifting or Cracks in your foundation is many times a result of excess moisture underneath your home. Poor gutter systems are a significant contributor in allowing extra water near your home's foundation.

If you see water coming over the sides of your gutters during a rainstorm it's a clear sign your gutters are clogged or not set up properly. Call for inspection immediately before it gets worse!

A telltale sign that your gutter system is beginning to fail. It means your gutter is loosening and at imminent risk of failing. Failure to address those issues could mean expensive repairs later down the road.