What might be wrong when the pool will not backwash trying to open it for summer?

There are a few potential reasons why a pool might not backwash when trying to open it for the summer:

1. Clogged filter: The filter could be clogged with dirt, leaves, or other debris, preventing the water from flowing through it properly.

2. Dirty skimmer: The skimmer basket could be full of leaves, dirt, or other debris, preventing the water from being drawn into the pump.

3. Closed valves: The valves on the filter or pump may be closed, preventing the water from flowing through the system.

4. Broken pump: The pump may be broken or malfunctioning, preventing it from generating enough suction to pull the water through the system.

5. Leaks in the system: There may be a leak in the plumbing, preventing the water from flowing through the system properly.

It is important to troubleshoot the problem and try to find the source of the issue before attempting to open the pool. Here are some steps you can take to identify and fix the problem:

1. Check the filter and clean it if necessary.

2. Empty the skimmer basket and clean it if necessary.

3. Ensure all the valves on the filter and pump are open.

4. Check the pump to ensure it is working properly.

5. Look for leaks in the plumbing and repair them if necessary.

If you are unable to find and fix the problem yourself, you may need to hire a pool professional to inspect and repair the system.