3800 Vented Loop?

[GeoDoc]

Does the factory installed overboard waste system include a vented loop between the pump and the through hull valve? The instructions for a Dometic T pump call for one.

I am gathering the parts to install an overboard pump out on my 2002 3800 which is now on the coast rather than where it spent most of its life on an inland river.

[ReelMagic]

There is NO vented loop between the pump and the through hull valve on my 2003 38 Open. follow this link to what I believe the installation should look like: https://www.dometic.com/en-us/outdoor/hy...v-dc-33614
Go to the bottom to "downloads" and open the .pdf file