Do washing machine waste hoses have a non-return device fitted?

seatbeltnoob

Sink gets blocked frequently and when I plunge it - it does clear. I'm just curious as to whether the waste pipe is actually being unblocked or whether the water is going into the washing machine.

The washing maching waste is connected to a waste T pipe that is fitted to the plughole of the kitchen sink.

I dont have any major reasons to suspect that it could be going into the washing machine other than the fact that there was one incident where the washing machine did not rinse correctly.

Ruski

In a word - no

Hth

Russ

DigForVictory

+1 for no, and well worth considering fitting.
<shudders at memory>

EssexExile

Water from the sink will go out the easiest way, if the drain is blocked it will go into the washing machine instead. The first people usually know of this is when the washing machine fills up with dirty water when not in use.
What are you doing that blocks the sink often?

missile

Get you drain cleared.

getmore4less

If the drain goes outside could be fat build up(during the winter it solidifies near the exit) and will need a proper clean.

A plunger won't do it even chemical will struggle, get under the sink and check the pipework might need dismantling to get some cleaning rods on the case.
I used a bit of old hose pipe a couple of years back when we had the problem one winter.

Le_Kirk

If your Washing Machine drain hose is fitted correctly, it should lift up higher than the sink outlet before being put into a pipe of it's own and have a trap (P or S). This is to prevent water ingress into W/M because water doesn't flow uphill and to prevent smells coming from the drain.

EachPenny

Le_Kirk wrote: »

If your Washing Machine drain hose is fitted correctly, it should lift up higher than the sink outlet before being put into a pipe of it's own and have a trap (P or S). This is to prevent water ingress into W/M because water doesn't flow uphill and to prevent smells coming from the drain.

Strictly speaking, water doesn't flow uphill in a conduit with a surface open to atmosphere.

That's an important distinction with washing machine drain hoses because they are capable of allowing water to flow uphill through syphonage.

Hence the need either for sufficient air gap, or else some form of anti-backflow valve. The typical under-the-sink washing machine drain often doesn't provide sufficient air gap.

Le_Kirk

^^^ Agreed re syphonage but if the drain hose is of the correct length and doesn't sit in the water in the trap, syphonage shouldn't occur. Valid point to alert the OP though.

molerat

For sink waste fitted WM connections I usually try to bring the hose in high then drop it down to the waste connection. My own is fitted the old fashioned way into an open top standing pipe with trap.

JohnB47

getmore4less wrote: »

If the drain goes outside could be fat build up(during the winter it solidifies near the exit) and will need a proper clean.

A plunger won't do it even chemical will struggle, get under the sink and check the pipework might need dismantling to get some cleaning rods on the case.
I used a bit of old hose pipe a couple of years back when we had the problem one winter.

Couldn't agree more with this. We had problems with our bath drain - gluging and slow to empty. I got outside, took the caps off a couple of the waste fittings and rodded the pipes, with a sponge firmly tied to the end of the rod. Worked a treat - loads of gunge, particularly on the pipes outside the house. I agree that no end of liquid solutions will clear this stuff - it needs to be removed physically using some sort of rod and brush affair. I'm going to do this every year from now on.

As suggested, get under the sink, dismantle what you can and rod out the waste pipe. Search for something like "Sink Drain Clog Cleaner Brush - Flex Cable" but I wouldn't expect to use it through the plug hole. I'd use it on fairly straight pipe - a bend might be OK but not round an actual s bend or trap.