I have a Bryant heating and AC, Model FB4A, and it has developed an overflow of water from the drip pan. What is the usual procedure for repairing this type of problem?

Clear the drain line. The drain is pluged up. Ususlly there is a pvc/plastic drain line that is white.

The plug is usually right where the line is connected to the pan. Dust and lint-like material starts to collect and floats on the condensate. As the pan drains the lint collects at the start of the drain. I have sometimes used a turkey baster.