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What fitting for washing machine outlet connection to undersink trap?

Hi,

What fitting do I need to use to attach a washing machine outlet pipe (corrugated plastic pipe) to the undersink trap, and do I go in through the screw on cap on the trap or the drill out nipple? I'm thinking the nipple is too small for the washing machine flow rate. The outlet pipe is approx 30mm in diameter with no fittings currently on the end of it.

Thanks.

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JDE

Just_me

Our last 2 and current front loader have been plumbed through the nipple. The waste pipe normally has a rubber end. Drill out the nipple and use a ring clamp to hold in place.

JDE

EricL

Hello @Just_Me

Thank you so much for sharing your question about washing machine outlet connections.

Your reference to the outlet hose for the washing machine is spot on. It is the Kinetic 2m Grey PVC Washing Machine And Dishwasher Outlet Drain Hose. The ends on this hose are standard at 19mm for under the sink and 25mm for the machine side. They are heat-sealed and can't be removed or modified. I suggest using Prime 16-27mm Solid Butterfly Screw Band Hose Clamp for the 19mm end and using the Prime 22-38mm Solid Butterfly Screw Band Hose Clamp for the machine side.

Please note that some washing machines use brand-specific hoses and will not accept generic ones. I recommend using the standard nipple on the under sink trap and drilling it out. The traps under your sink are rated for washing machine and dishwasher use. I suggest using the barbed nipple as it is easier to link to and clamp on rather than trying to find a compatible hose with a screw-on fitting.

Would it be possible for you to post a photo of the under sink trap to give us a better idea of the screw-on part you are referring to? Any update photos you can provide while installing your washing machine would be much appreciated.

Let me tag our experienced member @TedBear for his recommendations.

If you need more advice or information, please let us know.

Eric

Just_Me

Hi,

Thanks for your responses. I have a fairly basic Simpson top loader washing machine and the hose has no rubber end on it.

I've uploaded pics of the screw cap access to the trap as well as of the nipples.

Could I use something like this:

https://www.bunnings.com.au/abey-40mm-pvc-connector-waste-trap_p4760789?store=6126&gclid=EAIaIQobChMI5ej1hMCC8gIVzBErCh1_WAwFEAQYASABEgL7t_D_BwE&gclsrc=aw.ds

and connect it to the access where the screw cap is? Not sure how to firmly attach the washing machine outlet hose (with no end fitting) to either this connector or the nipple (not sure a ring clamp works on the corrugated plastic hose when there is no rubber fitting on the end).

EricL

Hello @Just_Me

Thank you for the update. I recommend changing your current hose to a new one. I suggest using the Kinetic 2m Grey PVC Washing Machine And Dishwasher Outlet Drain Hose. Your old hose no longer has the rubber end on it and will be very difficult to seal, without leaking. The Abey 40mm PVC Connector Waste Trap is not compatible with the inspection elbow. The cover for that elbow is custom-made to work only with that piece. It is not recommended as a mounting point as gases from the sewer will travel back into your washing machine hose making it smell.

If you find that changing the outlet hose is difficult, I suggest engaging the services of a handyman or qualified repair person from Simpson.

If you need more advice or information, please let us know.

Eric

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