I have a Hayward H400IDPL2 heater; I was getting an AO error in the display. I replaced the combustion blower, ignition control board, and blower vacuum switch. When I turned on the heater, the blower started, then ignition (flame, etc); after about 2-3 minutes I heard a metallic clanking sound. The combustion blower motor had 'collapsed' and sagged down -- enough to wedge against the rotating blower wheel and stop it. It seems like there is enough 'play' in the sheet metal holding the motor that it can flex in or out (?). I'm not sure why the metal is like this as it allows the motor to sag and stop the blower. Any thoughts/ideas? Also, this is the second blower I've replaced -- same thing happened with the first one. Thanks!