WM into 32mm waste (short run)

[LewisH80]

Hi there,

I'm looking to relocate my washing machine into a large airing cupboard now the old HW cylinder has been removed. I have a cold water feed and electricity already, but no waste pipe. The bathroom is situated right next door, with the wash basin very close to the dividing wall.

I have a "universal bottle anti-syphon trap" that can connect to the 32mm basin waste, and either 32mm or 40mm waste pipe. The current 32mm waste drops about 60cm, then 1.5-2m into the soil stack...

I have referred to the WM manual, it states nothing about the waste pipe size requirements.

To replace the waste pipe to 40mm will require removal of the boxing in to access the soil stack etc.

Is it worth it? Will such a short run cause problems? Most washes are short cool washes...

I could install an access an access point to deal with any potential blockages.

Any thoughts?

Thanks!

 

[oldbutnotdead]

Its not really blockages you have to worry about, its how quickly and how much water the washing machine pumps out. Is there anything in the wm manual about discharge rate? (Litres per minute and volume discharged)
EDIT A bottle trap would be unwise for a washing machine, a U bend presents much less resistance to water flow

 

[Hugh Jaleak]

+1. Washing machines need a minimum of 40 mm diameter waste to handle the volume of water being discharged, 32mm is unlikely to be able to take the flow, and as the pipe slowly gunges up, the first you'll know there's an issue, is when it overtops and floods the place.

In your situation you'll need a standpipe to hook the discharge hose into, these are only available in 40mm, and reducing that into 32mm will be your first point of restriction. NOT advised, you need to run in 40mm to the stack.