I have an american standard furnace that won't stay running. At first the pilot light wouldn't light so I changed the themocouple. After that the pilot lit and stayed lit the furnace kicked on ran for about 5 min fine and then the pilot light went out again.

A few things can make the pilot go out. Dirty pilot orifice-- pilot flame not strong enough to heat thermocouple. Hole in heat exchanger-- the blower is blowing pilot flame out or away from thermocouple. Pilot limit switch--- A limit opens that keeps the pilot flame burning.