Maximum height for washing machine drain?

[Morakot]

What is the maximum height for the drain into which a modern front loader washing machine can evacuate its waste water?

In my utility room there is a waste water pipe about 40 cm above the floor. I indent to install a 45 cm vertical standpipe onto that pipe that will act as an air break (see picture).

I am planning to buy a front loader washing machine that evacuates the water with the aid of a pump.

1. Will this work?
2. Is a trap seal required? The entire plumbing system finally discharges mid-air into an open cistern.

Edited May 10, 2014 by Morakot

[AhFarangJa]

As most modern machines are fitted under worktops ( in European kitchens anyway), why would there be a need to make the pipe any higher than the machine? also as Arjen says why the air trap?

[Morakot]

It will work. I only do not understand the function from the "air break"?

The 45 cm standpipe will prevent the dirty water in the plumbing system flowing (back) into the washing machine. It will also preventing the discharged water spraying all over the place for a pipe that is just hung in rather than installed with a screw-in fixture that needs to be ventilated separately.

[Morakot]

As most modern machines are fitted under worktops

As per OP, a utility room where the waste water pipe is at 40 cm height that is the situation.

Air break standpipe are normally at least 45 cm high.

Edited May 10, 2014 by Morakot

[Morakot]

To prevent back flow a gap from 1mm will.also do.

According to which plumbing code is this?

[AhFarangJa]

Hi Morakot,

The pipe on my machine in the utility room is just pushed down into the 45mm drain pipe for about 200mm. The drain pipe is about 600mm from the floor, works fine. But I always remove it and cap the end when not in use as I have heard of "things" crawling into the machine before.

[VocalNeal]

Front loaders come with a pre bent hook like hose. If the machine is against the wall the height is therefore fixed at something like 30 inches.

[taiping]

Look at (or download) the instruction manual for the machine you want to buy.

I recently bought a Samsung WF1124 washing machine - the instruction book says the stand pipe (quote) "must be no shorter than 60 cm and no longer than 90 cm" with a recommended 65 cm height. Minimum diameter is stated as 5 cm.

No water trap is specified and I do not use one.

The machine came with a plastic fitting to bend the flexible drain pipe into a "U" shape so the free end just sits in the stand pipe.

[donmuang37]

Don't make this difficult; just check the installation instructions for the washer before you buy it. It should specify the proper height and diameter for the home drain pipe. If not, select a washer which provides that info. Keep in mind that if the drain pipe is too high, the water may not drain properly from the washer. Any air gap is sufficient to prevent back flow. Water doesn't flow upwards through air.

I installed a GE washer per directions: open 2 inch pipe, "x" inches above the floor. Simply hung the u-shaped washer drain pipe into the home drain pipe; not sealed. After the flood, the GE was replaced by a Whirlpool. Did not need to make any modifications. The installation has worked well for 11 years with 2 different washers. Good luck.

[eyecatcher]

Don't make this difficult; just check the installation instructions for the washer before you buy it. It should specify the proper height and diameter for the home drain pipe. If not, select a washer which provides that info. Keep in mind that if the drain pipe is too high, the water may not drain properly from the washer. Any air gap is sufficient to prevent back flow. Water doesn't flow upwards through air.

I installed a GE washer per directions: open 2 inch pipe, "x" inches above the floor. Simply hung the u-shaped washer drain pipe into the home drain pipe; not sealed. After the flood, the GE was replaced by a Whirlpool. Did not need to make any modifications. The installation has worked well for 11 years with 2 different washers. Good luck.

Whether it is a 1 1/2 ", or 2" follow the height recommendation and make it 36", because that height is determined by the manufacturer as the height the pump is capable of pumping to, and the height that protects the washer against a backwash. Most washers specify 33", and minimum 1 1/4". Roper specifies 39" Once the water is in the standpipe, it just falls. By the way, if 1 1/2" is larger than your outlet hose, it is plenty big enough. If a plumber does not like it, maybe there is a municipal regulation calling for a larger pipe. Alliance specifies either a 11/2" or a 2", and a 36" height. Amana specifies minimum 36", and does not mention diameter. If you have a shorter stand-pipe than specified, you need to install a siphon break.

Simple!!!

[diyer]

Hi Morakot,

The pipe on my machine in the utility room is just pushed down into the 45mm drain pipe for about 200mm. The drain pipe is about 600mm from the floor, works fine. But I always remove it and cap the end when not in use as I have heard of "things" crawling into the machine before.

By installing a 'U' bend in the washing machine waste as in Morakots diagram, it creates a 'sump' of water which not only blocks nasty drain smells, but also stops creepy crawlies entering through the pipe.

Morakot: The upstanding pipe should not be any higher than the height of your washing machine

[kaveh]

as high as the height of your washing machine itself

[bankruatsteve]

FWI: Several months ago, I changed the plumbing for our washer to feed the garden instead of filling up the cesspits. I put the 1" PVC maybe 20cm above floor line and no U-trap - just normal elbows and under the concrete out to the garden. Everything good.

[Mudcrab]

Mate, a Thai washing machine doesn't have a pump...it just drains to the floor

[RBOP]

The stand pipe for my washer drain is 2 inches lower than the top of the washing machine and never had problem. My pipe is 1 1/2 inch diameter.

[RBOP]

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Mate, a Thai washing machine doesn't have a pump...it just drains to the floor

Never heard of a front loader without a pump.

[SOTIRIOS]

...top of the line...electronic....top load....

...the hose is at the bottom for a reason...about 3-4 inches above the ground....

...any higher....water will always remain in the hose....and eventually begin to smell......

[JesseFrank]

My setup has a 90 cm high pipe with the trap seal about 15 cm below the top.

[JesseFrank]

...top of the line...electronic....top load....

...the hose is at the bottom for a reason...about 3-4 inches above the ground....

...any higher....water will always remain in the hose....and eventually begin to smell......

That's why it has a pump build in.

[Loles]

Just checked for your good mood, mine height is 52 cm with out any U section under.

[Doc46]

It depends on one thing,,,Has your washing machine got a pump?? If it has a pump you can go up to normal bench and sink hight.If the machine does not have a pump the drain hose can't be more then 10cm of the floor otherwise your machine will not drain ..I just got a new washing machine and it does not have a pump,,,I thought it did like all the modern machines in AU,, BUT NOT HERE IN THAILAND no Sir.

[krisb]

Our front loader drains into the laundry sink/trough. So perhaps a metre or so off the ground.

No problems.

[krisb]

...top of the line...electronic....top load....

...the hose is at the bottom for a reason...about 3-4 inches above the ground....

...any higher....water will always remain in the hose....and eventually begin to smell......

Mines been pumping into the laundry sink for a few years now and never ever once had any smells.

[Pib]

My standing pipe is 78cm/31 inches high....almost to the top of the washer Works fine. I stuff a piece of foam around the opening just to keep critters from crawling in or out...on the end that discharges into my outside drain/sewer pipe I have a U-trap installed just to prevent any smells from coming back up the pipe into the washing machine area...also helps to keep critters out.