Community modification · Plumbing
Replacing the restrictive older drain path with larger ABS pipe, two gentle bends, and a continuous downhill run improves both flow and usable tank capacity.
At a glance
The project, consolidated
Tom traced slow drainage on his 2005 17-foot Casita to the original outlet arrangement: 1½-inch pipe extended into the tank, the route used three 90-degree turns, and part of the run was slightly uphill.
He attached 2-inch ABS outside the tank outlet, replaced the sharp turns with two 45-degree fittings, and maintained fall to the bottom of the 3-inch dump valve. The result was noticeably faster flow and better access to the tank’s capacity.
Owner photographs
Photos are reproduced as visual documentation of this community project and credited to the project owner.
1 / 1How the approach works
The useful part of the thread
Several commenters described faster dumping and recovered usable capacity after similar conversions. The exact gain depends on the original plumbing and the shape of the tank.
Plumbing alone may not fully empty a tank whose bottom sags below the outlet. Owners suggested temporarily raising the curb-side or opposite side with a 2×4 or Andersen-style leveler while dumping.
The discussion referenced Gene’s Casita Forum instructions and a complete Little House Customs kit. Owners who did not want to work under the trailer suggested a mobile RV technician or small independent shop.
Commenters noted that Casita revised part of the arrangement around mid-2017. Inspect what is actually installed before ordering a kit or copying dimensions from an older trailer.
Other ways owners handled it
Community-sourced summary. This page consolidates an owner’s Facebook post and the practical points raised in its comments. It is not Casita factory guidance. The original thread may require Facebook sign-in or group membership.
See the post and full discussion ↗