Sum Guy wrote:
wrote:

Just tell us one thing smart guy. What does the plumbing code say
about what you are doing?

Building codes are based on engineering principles.

We are discussing the fluid engineering principles of dishwasher
drainage.

What we theorize about what is needed for the correct and safe operation
of a dishwasher drain system should be (but may not be) described in the
local building code.

As far as I can tell, this is a copy of the building code for my
jurisdiction:

http://www.hastingshighlands.ca/uplo...ode%202007.pdf

It does not specify if a trap or air gap or air break is needed for a
domestic dishwasher.

This thread:

http://www.inspectionnews.net/home_i...al-inspection/
20168-dishwasher-directly-into-trap-crawlspace.html

(re-assemble the long line as necessary)

has a post that says this:

-------------
Here is what the NC plumbing code says -

802.1.6 Domestic dishwashing machines.

Domestic dishwashing machines shall discharge indirectly through an air
gap or air break into a standpipe or waste receptor in accordance with
Section 802.2,
--------------

An air gap (or air break) is presumably formed by an up-loop in the
drain line. I believe this is an acknowledgement that such an
arrangement would always lead to some water sitting in the dishwasher
basin and pump, effectively forming it's own trap.

What would any home inspector say when he spotted a dishwasher or
washing machine that was tied directly into the sewer with no
trap?

Again, any appliance that has it's own pump may require that it's
discharge line rise to some level relative to the top of the device
before being connected to a drain pipe or drain stack. I'm not aware
that washing machines need their own trap (if installed remote from a
sink) and I've never installed the pumbing for a washing machine.

And besides, as a home-owner, I don't have to know or follow the code
for things that don't need a permit.

And if you're so smart,

It's not a question of being smart. If you understand that the plumbing
code is trying to enforce a certain engineering principle (that there
should be no direct air connection between the sewer air and household
air) then we can theorize how such a connection does (or doesn't) happen
when considering a given dishwasher drain configuration.

Since I'm NOT smelling sewer gas in my kitchen or in my dishwasher, I
think we can move off this tangent and get back to my original question,
which is:

Do dishwashers depend on their discharge line running up from the drain
pump and forming an up-loop before falling down to make a connection to
a drain line? Do they depend on this arrangement to prevent fill water
from draining unintentionally from the machine?

I vote yes.