I have a question about 007-F5 series circulator. I have a 007-F5-12 installed. I found in Homedepot there is 007-F5 available. By looking at the specification on both circulator's body, I cannot see any difference except the model number: "007-F5-12" and "007-F5". Are them exactly the same circulator or there are some differences I didn't found out?