When I start my furnace the flame starts and than the fan will come on and the flame will go out and it will continue doing this until I shut it off. And some times the fan will be stuck on until I shut it off directly from the power switch, also there is a blinking red light on the furnace . Any idea what could be causing this?

How many blinks on the lites and brand and model of furnace?

I have an American Standard model #HA03236D175B160573 and the red light is constantly blinking while the heat is on.

Continuous blink =
False Flame or Gas Valve Relay Shorted

OK thanks a lot for the reply

You have any idea on how I could fix that?

Try cleaning the flame sensor with a bit of steel wool or sand paper.

Thanks a lot ill try it and let you know how it goes.

Well I used sand paper on the sensor and hooked it back up and the red light is still flashing and the heat went on and suddenly went off again. Any other ideas as to why the light would be flashing red and heat still not staying on?