Is it possible sink water is going into my washing machine?

mdstar

Above is the plumbing under my kitchen sink. I am diagnosed with OCD and get really worried about sink water going into my washing machine and often find myself re washing loads to be sure. 

Today, the kitchen sink had some water in and the plug in. I was also running the washing machine. But by the end of the washing cycle, it didn’t and the plug was at an angle. I know the sink gurgles with air when the washing machine pumps water out, so now I am concerned whether the dirty sink water would’ve got into the machine at the point when it was pumping out it’s water. 

The clothes themselves looked clean enough when I got them out but now I cannot stop worrying and thinking I need to rewash them. 

On an additional note, I also noticed when the washing machine was pumping water out that the water in the toilet swayed a little. Is that normal? Is this something I should get someone to look at? 

Thank you for any help. 

Mr.Generous

If the sink water can flow uphill it is possible, but water tends to go down not up The other way round is more common, any restriction (part blockage) in the waste pipe and the washer can fill the sink because the waste water is pumped out - your sink just drains by gravity.

cymruchris

If as I'm guessing that light grey pipe up to the left comes from the washing machine, then no, sink water will not be going into your washing machine. 

The water you see in the toilet is sitting on a U bend - so if there's drain activity further down the line where air and water is rushing about on the way to the sewer, then it's possible you'll see a little surface movement in the toilet water, but nothing to worry about. It's not going to suddenly splurge out when you're not looking and flood the bathroom. 

Newcad

As long as that grey pipe goes up higher than the sink overflow (the top of the black pipe) before coming down again to join the waste pipe then sink water can't get into the machine.

So make sure that the pipe from the machine goes up then down again.

What you describe with the sink emptying is normal if the sink is not that full of water.

What happens is that when the machine starts to pump water out there is a very brief increase in air pressure in the waste pipe, a second or less.

If there is only a small amount of water in the sink then that brief increase in air pressure can be enough to push the plug out from underneath.

Which is why your plug was sat at an angle, the air pressure had pushed it up.

The main point is that as long as the pipe from the machine goes up higher than the sink overflow before coming back down again then water can not go from the sink to the machine.

There is usually/often a U-shaped bracket fitted to the side of the cabinet to keep the pipe up above the sink overflow.

It's hard to tell but I think I can just see the bottom of one of those brackets in your photo.

PS. It's the same with dishwashers as well as washing machines.

Murmansk

The pipe which takes waste water from the washing machine only does two things, it sits there doing nothing or it has water FROM the washing machine coming out of it. The water from you sink goes downwards, past where the waste water pipe from your washing machine is but it won't go into the pipe from the washer 1. Because it'd have to go uphill and 2. Because the pipe would need to be "sucking" for water to go UP it.

outtatune

You're fine, as others have said.

Even if the waste was completely blocked you'd be seeing that in the sink well before it gets close to the washing machine.

You don't have any children in the property who could access those tablets I hope?

cerebus

OP - for peace of mind you can check if you have a non return valve fitted to the washing machine waste on the trap, if you unscrew if you will see a black rubber diafaph which only opens one way, if you haven't got one you can buy the washing machine attachment with them fitted very cheaply and simply swap the parts out