American Standard high efficiency furnace repair. After cleaning my inspection found screens on pvc pipe outside, the intake and exhaust blocked. The furnace was locked out on the pressure switch so I went back in to reset furnace. The furnace came on found 3 problems 1- draft inducer really noisy 2- blower motor really noisy 3- dirty filter Replaced inducer motor and blower. Furnace is a lot quieter. I also washed blower wheel when changing the motor.