Dishwasher drain length

[pieta.esplin]

Hi,

I'm building a new home, and the builder just called to let me know his plaumber had told him that my dishwasher was too far from the kitchen skinks drain vavle.

I know the length most dishwashers come with is around 2 meters. My dishwasher is going to be just over 3 meters from the dishwasher.

If the dishwashers pump's aren't designed to pump water tgis far, isn't it as simple as extenting the plumbing under the sink to a bit closer to the dishwasher?? I'm confused as to what restrictions apply here. The other option is to have the dishwasher on either side of a corner, means 2 doors will be blocked ehwn the diswasher door is open. I'd like to avoid this option but i don't want to be left with a dishwasher that can't drain..

Any help would be welcome.

Mike

[SJF]

Unless it would be unsightly, you could probably use the longer hose. The washer will still pump out the water but it may take just a little longer (no more than 20%) because of the extra hydraulic friction due to the 50% longer hose. That should not be a problem but you could check the function of the machine by filling the tub and going through the pumpout cycle. What you'll probably find is that the machine will pump out all the water and then continue the pump operation for a while until the timer starts the next cycle.

I've had two machines that pumped too fast for a poor drain pipe and overflowed the drain. I put flow restricters in the hose to slow the discharge with no ill effects.

Adverse effects on the pump and motor? No! Centrifugal pumps reduce the load on the motor when the flow rate is throttled.

But since you're currently building a new house, a plumbing adaptation might be a better long range solution. Also, there may be building code considerations.

SJF

[SJF]

Oops! I misread the original post and read "washing machine" where it said "dishwasher". But it's a similar situation except that you wouldn't be filling the tub to run a test.

SJF

[George E. Cawthon]

The distance isn't going to make much difference, the big pump load is to move the water above the drain point (to avoid siphoning). Many dishwashers conveniently connect to the garbage disposal. However they don't need to and you could simply extend the kitchen drain toward the dishwasher as you suggested. All you need to do is be sure you have a trap downstream of the dishwasher outflow. If you extension is below the kitchen sink trap then you need to add a trap in the line you extend for the dishwasher. By the way "what is a kitchen sink drain valve?" I presume you mean the drain trap since there are normally no valves in a drain.

[SQLit]

What does the manufacture of the dishwasher say about the drain hose? Specifically size and distance.

Your builder certainly is not coordinating much.

[Mike & Ched]

George,

By valve I mean the nozzle that you clamb the hose to on the plumbing under the sink. I think it's called an S-Bend over here (I'm from Down-under).

SQLit,

I don't own a dishwasher yet. I just checked the specs on one candidate machine and it offers extenions up to 3.6m above the 2.2m spec. But it also has contrainsts on the installation:

Page 4 of above shows the installation method, so I think the 5.8m is really enough to go the distance.

But this dishwasher is the most expensive candidate. The other one is a whirlpool but there are no lonks to it's spec.

I guess the builder is trying to avoid having to bear the cost of extending the plumbing.

Mike

[buffalobill]

who: your architect or your plumber and a carpenter what: need to confer. where: to extend the 1-1/2" drain line and a required vent line to the roof. when: preferably before the walls are up during plumbing rough-in or sooner. why: to meet code requirements and dishwasher specifications. how: with your money.

[buffalobill]

here's pdf link to oatey for a sure-vent if your walls are up this may be permitted find out:

[trader4]

I think this is correct. Most dishwashers are installed with a simple high loop, where the hose is routed up to the underside of the counter after it leaves the dishwasher. From there, it's all downhill to the drain. So the real work done by the pump is to lift the water up to the bottom of the counter, regardless of the length of hose run, unless it was extremely long. 3 meters will be a piece of cake!