Best way to run a long waste pipe from washing machine

[Carbretta]

Hey all,

I have recently moving my washing machine into the utility room next door to make way for my new dishwasher. I have already cored a hole in the wall which is near the botom of the wall and have run the cold water inlet hose through it with no problems. I have 2 waste flexi hoses connected together to reach the distance and have to choices for this. 1 - I can pin the hose up straight out the washing machine to a height approx 8" above the height of the sink trap, then run it back to the floor, through the hole, about 2.5 meters along to the sink then back up to the trap, or still pin it up straight out the machine then core a hole higher up so there is not so much up and down distance for the water to travel.

Basically if I pin it up at a height 8" higher than the trap by the washing machine, does it matter if the pipe then drops down and back up again? I assume not as long as at no point it goes higher than the initial point I pin it up?

Any help appreciated 🙂

 

[joni os]

Unless there is something in the MIs. suggesting otherwise, just run extended waste along floor through existing hole and raise to trap connection.

 

[stevetheplumber]

you should never run them low best to rise as high as you can under the worktop and run down towards the trap that way it drains on gravity and no there should be no dips in it

 

[rpm]

Unless there is something in the MIs. suggesting otherwise, just run extended waste along floor through existing hole and raise to trap connection.

Even if that did work which I very much doubt it would the results would most likely be a new pump every year, the horizontal section of this pipe would have water in it so everytime the pump discharged new water it would have to push this water through and up to the trap, overworked or what!

 

[rpm]

you should never run them low best to rise as high as you can under the worktop and run down towards the trap that way it drains on gravity and no there should be no dips in it

Agree with that, just imagine a water slide and let gravity do the work not the pump.

 

[joni os]

Mgh=½MV² Before you can use gravity the pump has to do the work.

 

[rpm]

Not gonna start Algebra calcs on a Friday, but you would have to take in to account the length of the horizontal pipe, the loss of the Kinetic energy as new water hits old and the rise at the end of the pipe run would you not? Where as up first and let it flow away sounds better to me.

 

[JCSPLUMBING]

Waste pipes should fall from trap height. 3m max length for 40mm. Longer than this uprate to 50mm.

 

[joni os]

The trap will be approx. 600mm above pump. The OP is suggesting raising discharge an extra 200mm requiring an extra 33% work for the pump. Its the equivalent of adding an extra tread to your staircase so you can step down on your landing.

 

[rpm]

The trap will be approx. 600mm above pump. The OP is suggesting raising discharge an extra 200mm requiring an extra 33% work for the pump. Its the equivalent of adding an extra tread to your staircase so you can step down on your landing.

That part is ok, however he said ........Up, then down to floor level for 2.5m (so pipe will have water laying in it for 2.5m) then he is coming back up to the trap (as you say 600mm). If it was up, along and then down that wouldn`t be a problem it`s the second rise and the water in the horizontal that is the killer.

 

[stevetheplumber]

even straight of the machine at low and then rising to the trap means scummy water laying in the pipe with sediments dropping out pump would have to move all that water

 

[stevetheplumber]

ive had to unblock a fair few laid on the floor and blocked solid every washing machine ive ever fitted says up first then steadily down to the trap