I had a plumber do a job for me a couple of days ago and since then the washing machine, when not in use, has been filling with approx 2 inches of what I can only assume is sink waste. The machine drains fine after use and is empty when turned off but the water is there in the morning or after a couple of hours of not checking it.
Is there a plastic non return valve I can put on, or just after, the trap ?
Thank you
Is there a plastic non return valve I can put on, or just after, the trap ?
Thank you