I have a newly installed Raypak 406A Electric Iginition which replaced a 15 y/o Hayward H400 Millivolt. My first experience, and just about everyone else's with the Hayward (about 5 years ago), was "Wow that heater really works", when I placed my hand in front of a return. With the Raypak, it's more like, ehhh, it's warm but nothing like the Hayward. Do I have scientific proof? No, just my fingers, but I'm a little disappointed. Can somebody explain the difference? In case you are wondering, I haven't changed anything else but the heater.