Arrived on site to pressure switch code flashing on control board. Opened flue pipe to check if chimney was blocked and it wasn’t it was clear. Pulled off hose from pressure switch and inducer and cleaned out debris from inducer port going to pressure switch. Tested and cycled furnace 3 times and furnace is operating properly at this time. Highly recommend new 40 gallon gas tall water heater. Water heater is 15 years old and in poor shape.