Re: Washing machine causing bathtub & toilet issues
It is possible for a blocked to cause a slow drain if there's an air lock (a bubble inside the pipe), but that generally only happens on smaller diameter pipes like those that drain a sink. The larger lines that drain a toilet are ordinarily too big to develop an airlock.
Based on the symptoms, you more likely have a blocked drain than a blocked vent.
The "Senior Member" designation under my name doesn't mean I know a lot, it just means I talk a lot.I've been a DIYer since I was 12 (thanks, Dad!). I have read several books on various home improvement topics. I do not have any current code books I can refer to. I was an apprentice plumber for two years.