Our sewer line is 43" above the ground. Today, the washing machine drains into a washbasin, into an ejector pump, and into the sewer. I would like the washing machine to drain directly into the sewer line, bypassing the washbasin and pump. Can modern washers pump the water high enough to allow for a trap above the 43"?

  • Hi Josh. As you can see @mt_heady "empty head?" says his does it find. Good for him. You need to check your manual. You will notice most washing machines tell the maximum and minum heights of the outlet. One thing to worry about on high outlet is that water will fall-back into the washing machine, causes damp damage, fungi and other nasties! That is why there MUST be a loop in the pipe and it usually says not higher than the washing machine itself. I am sure it will work but it will reduce the life of your machine and possibly health issues for you too! What you have now is kinda correct.
    – Piotr Kula
    Jan 30, 2013 at 10:36
  • Also to be considered is all that volume of water in the hose that never gets pumped out, merely to drain back into the tub once the pump cycle quits. Aug 12, 2013 at 15:09
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    Graywater enthusiasts have a lot of experience running wash machine water greater than vendor recommendations. Have a google on that topic... I suspect you are just fine.
    – Bryce
    Aug 12, 2013 at 18:53

2 Answers 2


No. Well maybe it can, but it shouldn't.


If you check the documentation that came with the washer, it should contain the maximum drain height. Generally, the maximum height is around 39" (99 cm).

enter image description here

Newer washers often have a drain hose permanently attached, which is designed to make drain installation fool proof. The supplied drain hose shows you exactly how high the washer can discharge.

Raise the washer

Depending on the machine, and whether or not you're already using a pedestal. You may be able to raise the whole machine up, to accomplish what you want. The maximum height is not height above sea level, it's height above the bottom of the washer. So if it's possible to do so, raising the machine up a few inches (safely) might be the solution.

If it's a front loading washer; and you're not already using a pedestal, you may be able to purchase (or build) a pedestal to raise the machine up. If not, you may want to think about building a raised floor to raise the whole area up.

Keep it up to code

International Residential Code (IRC) says.

International Residential Code (IRC) 2012

Chapter 27 - Plumbing Fixtures


P2706.2 Standpipes. Standpipes shall extend a minimum of 18 inches (457 mm) and a maximum of 42 inches (1067 mm) above the trap weir. Access shall be provided to all standpipe traps and drains for rodding.

Which means if you connect the drain hose to a standpipe, the standpipe has to be at least 18" above the point at which water will begin to flow from the trap. So your 43" height, could quickly become 61".

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    "sea level"--lolz! Re: sealed trap discharge. I'm pretty sure this is against code. It would be considered pressure discharge. The standpipe arrangement is sort of a special exception to the requirement that indirect waste be discharged through an air gap. No standpipe invokes the air gap requirement the way I see it. Otherwise great answer.
    – bcworkz
    Jan 31, 2013 at 5:11
  • @bcworkz wasn't aware of the code limitation, can you site the applicable code (just curious)? Does that mean the image from the manufacturers installation guide is wrong, or it works because the sink allows air in?
    – Tester101
    Jan 31, 2013 at 13:07
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    Right, the air allowance makes all the difference. So the with the sink, it's just a standpipe connection. The instruction is potentially wrong still, standpipes must be 18" min. vertical! Also, few sinks are properly sized for washer discharge in addition to the sink fixture units. You may recall all my code references are out of date, but I'd be very surprised if this aspect changed, though it has likely moved. Anyway, I'm looking at '94(yikes!) UPC section 805, Pressure Drainage Connections in the Indirect and Special Wastes chapter.
    – bcworkz
    Jan 31, 2013 at 20:58

Most manufacturers will list the minimum height of the "top" of the Stand Pipe. Usually 30" from floor. The International Plumbing Code for the actual 2" Stand Pipe is 18" minimum and 48" maximum from trap. In regards to the "sealed trap", the piping being installed together, "is" against code. The Stand Pipe itself is not subject to the "Air Gap" code, but it is to the "Air Break" code. Meaning the washing machine discharge hose can be inserted "into" the Stand Pipe, no more than 5"- which falls into the Indirect Waste portion of the plumbing code. The washing machine discharge maximum height is 96" for top and front loading machines. However, installing the extended height above the washing machine could cause that extended height of water to drain back into washing machine. Causing excess water laying in machine, damp clothes, and a shortened life of the drainage pump in the machine. One alternative, is to use a laundry pump (with or without a sink). A Stand Pipe can be installed into the laundry pump itself. Local codes permitting.

  • What does " A Stand Pipe can be installed into the laundry pump itself." mean? how can you install a stand pipe in a laundry pump?
    – virtualxtc
    Nov 26, 2018 at 5:19

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