Dishwasher Drain

[Mike]

I am installing a new SHE33M02UC Bosch dishwasher in place of our old Gibson. With the Gibson I used a drain hose about 10' long, made up of a section of standard "corrugated" plastic dishwasher drain hose added to a section of smaller diameter hose. I have hooked the new Bosch up to this drain hose and everything seems to work perfectly. However, the Bosch installation instructions say the dishwasher should be located so that the drain hose length will not exceed 92". Later in the instructions they say a

92" length of drain hose is included which can be extended to a maximum of 150." A couple of questions:

- Why the concern about a maximum drain length? Is there a possibility of too much back pressure maybe damaging pump seals?

- Any ideas what drain hose maximum length Bosch really means should apply here, 92" or 150"?

- is the corrugated type drain hose extendable by pulling on it?

Thanks, Mike

[evodawg]

Sounds a bit confusing but I would try to be somewhere inside those dimensions. I don't think so, it's corrugated so it will flex and bend, not stretch. Does it look like it will stretch? Check a small section and pull lightly and see for yourself. The further you get from the pump the harder it is on the pump. Don't think it has anything to do with the seals but the power to pump that far. And remember you usually hookup to the garbage disposal.

[trader4]

Probably because that is what is included with the dishwasher.

Later in the instructions they say

Any pump has limits on how much resistance it can overcome. But usually the main concern is how HIGH it has to lift the water. As long as you're going mostly sideways or down, you're obviously safe per Bosch to over 12 feet. You do have to go up a few feet to either an air gap or just a high loop, but that is normal and accounted for in the specs.

How far and in what direction do you actually have to go?

[Mike]

The existing drain line is about 10' long with about a 24" loop height built into it. Overall height of the drain entry point under the sink is about

20" higher than the outlet at the dishwasher. It narrows in a couple of places as it goes through barbed plastic pipe couplers. However, I know the Bosch pump empties the tub completely because I can hear the change in the pump sound once it goes to no load.

Thanks, Mike

Probably because that is what is included with the dishwasher.

Later in the instructions they say

Any pump has limits on how much resistance it can overcome. But usually the main concern is how HIGH it has to lift the water. As long as you're going mostly sideways or down, you're obviously safe per Bosch to over 12 feet. You do have to go up a few feet to either an air gap or just a high loop, but that is normal and accounted for in the specs.

How far and in what direction do you actually have to go?