I am getting an AO error on a friends Hayward Gas heater.
The heater blower vacuum switch (rss-495-061) seems to work when I suck very lightly on it (when I do this the error instantly goes away) There is not any noticibly suction coming from the fitting on the blower (fan). The fitting is clear since I can easily blow and suck with my mouth, but yet when the blow fan is on I don't notice any suction.
The fan motor spin so i feel the motor is good. In my experience if a motor is running slow it will burn out. The squirrel cage spins very easily when off. The motor is quit when running.
This tells me its either the vacuum switch or the motor.