Stinky washing machine - how to cure?

[Jurek]

I think we've been here before, and I've done the soda crystals in the soap tray and in a ball and a 90°C wash with no laundry in it, followed by just a 90°C wash with no detergent - and I think that's actually made it worse.

It has a 'drainy' sort of stench, but I know it isn't the drains 'cos when I take a whiff of the kitchen sink plughole - it doesn't smell of anything.
I guess maybe the sink doesn't smell as it has the water trap in the sink waste.
The washing machine drain connects to the sink waste, after the water trap - so maybe it is getting full whiff of el-draino.

Any ideas?
Any weapon - grade chem that I should be flinging (maybe) down the sink?
Pleeze.

[perpetual dan]

Have you cleaned out the filter, and checked that the outlet tube is going up enough to isolate it (not fallen off the clip on the back)?

[Kim]

The washing machine drain connects to the sink waste, after the water trap - so maybe it is getting full whiff of el-draino.

This seems wrong to me.

[Canardly]

Waste should be trapped either its own or the sink waste. Also as above check the filter.

[Sergeant Pluck]

The washing machine drain connects to the sink waste, after the water trap - so maybe it is getting full whiff of el-draino.

The washing machine outlet needs its own separate U-bend or trap, but that is often achieved using a U-bend of the outlet pipe itself. Maybe the machine has been moved or the pipe has become unclipped so as to un-U the bend?

[Jurek]

The washing machine drain connects to the sink waste, after the water trap - so maybe it is getting full whiff of el-draino.

This seems wrong to me.

The more I think about this, the more I a) agree with you and b) think that what is coming through the drum of the machine is the unfettered stench of my drains.
Is there not any sort of one-way valve arrangement that could be introduced into the washing machine drain before it reaches the sink waste?
Lets washing machine waste water through, keeps the drain stench at bay.
That sort of thing.

ETA, I think there may be an absence of U-bend in my current arrangement

[Kim]

And if we're playing drains, there's also the possibility that all is not well downstream, causing a previously unproblematic trapless installation to start misbehaving.  Pigeon nesting in a vent, malfunctioning air admittance valve thingy, or good old-fashioned blockages full of nasty...

[Sergeant Pluck]

ETA, I think there may be an absence of U-bend in my current arrangement

Just make a suitable bend in the pipe. Washing machines come with a sort of plastic former to ensure that a U can be made in the pipe. Failing that, or if the pipe has to stretch too far to allow a bend, you could just get a longer pipe or (probably better) plumb in a normal under-sink type trap.

[hellymedic]

I think Giraffe installed some HepVO or Hep2O one-way valves to my kitchen sink outlet so these do exist.
http://hepvo.com

[Jurek]

Yeah,
As suspected.
Absence of u-bend.
There may've been one on the machine that John Lewis took away, but no evidence of one on this one.
Oh well.
Another weekend under the sink.
Good album title.

[Jurek]

ETA, I think there may be an absence of U-bend in my current arrangement

Just make a suitable bend in the pipe. Washing machines come with a sort of plastic former to ensure that a U can be made in the pipe. Failing that, or if the pipe has to stretch too far to allow a bend, you could just get a longer pipe or (probably better) plumb in a normal under-sink type trap.

A rummage through the kitchen drawer containing the sealed bag labelled 'Washing Machine Transit Parts' has revealed exactly this item. Unused.
I shall be deploying it during the next bit of free time I have.

Thank you all for your much sought after, and valued input.

[Mr Larrington]

(Sings)
10:15 on a Saturday night
And the tap drips under the strip light
And I'm sitting in the kitchen sink
And the tap drips drip drip drip drip drip drip drip
Etc

Better to write on the sole of your slipper with a Biro^TM instead of going to the pub, if you ask me.

[Adam]

You need to go round the bend Jurek!

[Brucey]

normally the washing machine itself is 'its own trap' in that the pump never empties itself entirely; this makes it difficult for drain smells to waft directly through the machine.  However if the machine isn't used very often, the water left in the bottom of the pump can soon go bad though.

The other thing that can happen is that if the other water in the drain can generate enough pressure, and/or the drain hose isn't mounted high enough above the T joint,  water can backflow into the washing machine.  This means that it is important that the outlet from the washing machine loops up as high as possible before going down to a T joint (which is I think what the bracket is really for).  If you are fitting two traps under the kitchen sink (a very good idea) it makes sense to have them at the same height as one another and (relatively) low down so that the one for the washing machine can have a tall entry stack on it.

cheers

[JohnR]

We have had this problem twice before in our washing machine, I think it's due to the low temperatures and the type of washing products modern fabrics require.

If it isn't the drains etc. try the following, maybe not the strip down.

Both times I have literally stripped the washer down and dismantled the drum assembly and manually cleaned all of the gunk buid up from the spider and out from all the pipes and soap dispenser etc. Usually takes up a full day. After the pipes have been cleaned with a brush and soapy solution with some bleach in it, you can still smell a slight pong in them and of course there is always some plastic pipework which is welded together on the outlet system which you cannot clean inside of.

I have extensively googled this problem and it takes a number of these washes to properly clean out the gunk and kill the breeding microbes which are causing the smell.

Do your wash with nothing in except a cup full of soda crystals, this is alkaline and should loosen the gunk and wash it away, of course if there is a lot of it it will take a number of goes.
Next do another wash with nothing in it except a cup full of distilled vinegar which is acidic, this is supposed to kill the breeding bacteria.
Don't do a wash with both in together as they will cancel each other out.

I have just done this with ours and the smell is slowly going. The above should ideally be done each month.

Good Luck!

[Sergeant Pluck]

This means that it is important that the outlet from the washing machine loops up as high as possible before going down to a T joint (which is I think what the bracket is really for).

I believe that is right - rather than using the plastic former to directly make a U as I suggested above, it's to allow the pipe to be positioned properly.

Another factor in all this is the type of detergent used. I looked into this a while back and the upshot of it all was:

- washing powder is far better for the machine and probably the clothes compared to liquid and those gel pouch doofers. And cheaper.
- bio washing powder is better for the machine, better at washing stuff, and the enzymes don't have a significant effect on the environment as I had previously believed (unlike phosphates and phosphonates which are bad).

[rafletcher]

I would beg to differ slightly. I think powders (or solid tablets) used at low temps (30C) can leave a chalky residue that can eventually obstruct the pipework...  as I found one Sunday morning having asked ny wife if she'd left a tap running downstairs, only to find the washing machine waste backing up as it was 50% occluded.  Liquids (we use Ecover) don't do this, or at least we've gone around 5 years with no evidence of it, supported by the plumber who had a look when sorting out our sink waste last week.

We do however get the smells, and it's the machine not the drains, we have a proper U-bend on the washing machine waste.

I'll get some soda crystals and try that in a couple of hot washes.  As for the acid, we use Killrock descaler so that shoud help kill the bugs.

[Aunt Maud]

Change your washing detergent.

We had the same problem and used a different detergent after a good clean and now no smell.

[Brucey]

FWIW the correct detergent will vary with the machine and the local water conditions. Also, the detergent manufacturers have been changing the composition of their detergents in recent years.

One of the ingredients that has often gone MIA appears to be the one that softens the washing water in hard water areas.  The result of this is that if you live in a hard water area, behind the shiny drum there will be no end of limescale ( a breeding ground for stinkyness) deposits in the drain hose (ditto)  and worse yet, it can even cause the emptying pump (whose bearings often run in the water, using it as a lubricant) to seize up intermittently.

My pragmatic approach to this is to add a big squirt of cheap washing up liquid to the laundry detergent with every wash. This softens the water (for pennies), improves the detergent action, and helps prevent limescale build up. I wouldn't recommend that you do this in a soft water area though; you will probably get bubbles coming out of the machine...

If you run a wash cycle with a pint or two of vinegar in the machine, this will help to shift limescale residues. It is worth doing this every now and then in hard water areas.

cheers

[rafletcher]

Change your washing detergent.

Not so easy if you want an un-perfumed one.

[fuaran]

The main problem is using too much detergent, which just leads to a build of grey slime. Usually 1/4 or 1/2 of the recommended dose is enough.

[Mrs Pingu]

When I had the fridge freezer fixed the repair guy asked about my washer and said they hated Ecover liquid on the basis that it foams up and creates corrosion somewhere. I'm still using it but only about 1/2 the recommended dose.
He said they recommend powder, something like Fairy I think he said. Thing with bio powders is you're not supposed to use bio on delicate gear or sport wear

[Brucey]

any recommendations about detergent types and quantities are IMHO pretty meaningless if they are not accompanied by a comment concerning what kind of water you have.  The idea of any detergent causing excessive foaming in my (hard water) area is simply laughable....

cheers
 

[rafletcher]

We only use a single cap of the non-concentrated Ecover detergent, but our stuff is generally all lightly soiled - and if the grease doesn't come out of my "shed" jeans, who cares.  We found the the Bosch machine we have washes a LOT better than the Hotpoint it replaced with the same level of detergent.

[rogerzilla]

White vinegar should get rid of the smell.  I doubt it's the plumbing since WMs always have some water left after a cycle and need pumping to empty normal waste - so there's not much of a pathway for sewer gases.