Recently the washing machine drain has been overflowing. I cleaned out the p trap with drano and flushed it. Seemed to work also the toilet near the washing machine is flushing properly now. It seemed to me that the drain pipe was clogged near the vent pipe. The drain pipe is still overflowing. The drain pipe is cast iron and has an extremely sharp p trap. Could the venting be the problem.
or is it the P trap. The house was built in 1966.