On 2009-10-21, Aaron Fude wrote:

My washer is basically at the same level as the main stack (or
whatever its horizontal equivalent). So there is not sufficient
elevation to have a p-trap on the exhaust (take my word for it - I
just can't do it).

Sorry, you must have a p-trap and standpipe. As others have
mentioned, you can raise the inlet of the standpipe as needed so the
outlet of the p-trap is high enough to tie into your horitzontal
drain. The pump on the washer should be capable of pumping high
enough to get to the standpipe inlet. Check your washer manual for
the maximum height.

If you really can't make that work, then the only alternative is an
ejector pump.

Yours,
Wayne