My washing machine is backflowing into my sink when it drains. I have cleaned out the sink trap, which has improved the situation somewhat - it's still backflowing but not as much. Does this mean the pipes are blocked too?
This could certainly be a reason. If the washing machine has only recently been plumbed in and this is happening from the word go then we suspect bad plumbing but if the macine has been there for a while and this has only just started then, yes,a blockage is most likely.