There are a few likely scenarios that can cause ice accumulation in downspouts.
Frozen gutter downspout.
In the recent storm the heavy wet snow was enough to block water flow at the bottom if the ends weren t shoveled clear.
If there is a large amount of snow on the ground that is covering the bottom mouth of the downspout.
Frozen downspouts occur during the winter during or after winter weather occurs.
Once the ice has melted it will drop the remaining ice through the spout.
This can lead to your gutter and downspout tearing away from your roof or siding leading to more costly and larger problems such as water leaks and improper drainage.
However consistently frozen or frozen solid downspouts may require immediate attention especially if weather conditions will be less than ideal for the foreseeable future.
Consistently frozen downspouts require immediate attention.
When winter storms hit gutters and downspouts sometimes freeze into solid blocks of ice and homeowners understandably worry about gutters pulling away from the roofs or ice dams forming.
Frozen downspouts can cause costly damage.
It will cause your downspouts to freeze.
Over time the ice may back up into your gutters themselves thereby creating extra weight on your entire guttering system.
Personally i would leave it if it s already frozen.
If you get a slug of ice or water to suddenly drop in it.
1 pour hot water full hot from the tap in the gutter and to get the downspout started if frozen solid at any point fill top with hot water to full then pour hot water on one side of outside of downspout to melt a small channel inside the pipe for the water from the top to start running down usually will only take 1 2 gallons of hot water dribbled down the outside to thaw enough interior channel to start flow then you can add hot water from top to melt out the rest.
If your spouts are underground you will want to detach the portion of the above grade downspout with a screwdriver first otherwise the ice will just sink below grade and you will have to dig it up.
Because of the thawing and refreezing this week downspouts also froze up at the elbows.
There is a chance of ruining the downspout no matter what method you use to thaw it.
Over time the ice can back up into your gutters creating additional weight on your entire gutter system.
Unfortunately dealing with frozen gutters is rarely simple or inexpensive.