Gunk inside washing machine waste pipe

[diyyid]

Hello

Every few weeks, my washing machine (AEG, 9yrs old) spin cycle time takes ages and each time, it's due to solid gunk inside the white waste pipe under the sink.

The waste pipe is a 20mm inlet with 40mm connector (like this https://www.screwfix.com/p/mcalpine...ppliance-tee-piece-connector-white-40mm/4167p)

The gunk builds up inside the 20mm area causing a severe blockage.

Does anyone know why this happens?

If I drain the washing machine grey pipe into a bucket, the spin cycle finishes within normal time.

If I clean the white pipe, it's OK for a few weeks and then it happens again.

I dismantled and cleaned deeper under the sink (inside the trap, etc) but I can't clean any further than that.

I don't think the problem is the washing machine - does anyone know how to solve this once and for all? Is there a blockage further down the waste system requiring a plumber? Sink drains at normal speed as far as I can tell. Or something else?

Washing machine receives a regular maintenance cycle and the filter is also cleaned regularly.

 

[Mottie]

Are you using the washing powder capsules? When you say it receives a regular maintenance cycle, do you run some degreaser through it?

 

[diyyid]

Using liquid detergent and softener for normal washes.

For maintenance, I use a dedicated washing machine cleaning liquid or regular detergent (if washing machine cleaner is finished) - both on a 95c cycle.

I don't know if the cleaner has degreaser in it tbh, never checked and didn't know it was a thing.

 

[Wayners]

Used powder.
Liquid causes black slime and smells so you have to run a cleaning cycle with the magic button press (see instructions for cleaning)
Over 60c temperature will kill bacteria.

Also 9 year old machine may have a weak pump as it's old which slows up the water flow.
Swap pump is easy sometimes.
Lay machine on its side and swap pump takes 10 mins and cheap at around £40 or less so worth a punt.

New pump and switching to powder solved our machine problems.

 

[CountryFan]

Does the grey hose have the correct fall?