Just a drain hole and I don't have room to install the kit without removing pex which I'm not touching. So I'll just hook up the hose from the kit to the pump every fall and do it that way.
Yep that's just a drain hole for the compartment. I bought the winterization kit as well and there really isn't much room to install it. I just disconnected the line to the water pump and used the hose provided with the winterization kit as well.