Permanent Black Holding Tank Rinser

If you’re tired of hauling the garden hose inside the RV to flush and clean the black holding tank, installing a permanent holding tank rinser may interest you. There are 3 permanent holding tank flusher/rinser device on the market that I know; one is the “Tornado Rotary Tank Rinser”, the “No-Fuss Flush” unit and the identical “Camco Quickie Flush” system. I went and bought the “No-Fuss Flush” unit as it was available at my local RV store. The “No-Fush Flush” unit does not come with an extension hose unlike the “Quickie Flush” seen on Amazon here: Click here. All of the above mentioned tank flush unit has a built in check valve to prevent any contents of the holding tank exiting via the flushing unit. The supplied holding screws (x3 zinc coated) for the "No-Fuss Flush" unit were not used, instead I purchased 3 stainless steel screws for this project.

1. Before starting with this project, make sure your black holding tank is empty; you do not want any surprises when drilling the required hole.

2. Raise the passenger side wheels on ramps for easy access to underside of the RV. For safety, chock the driver side wheels to prevent the RV from rolling off the ramps.

3. The installation location of the tank flushing unit is limited on the Agile as the only exposed side of the black tank is towards the rear end of the vehicle; all other sides are either covered by a shield or frame. Although, installing the flushing unit at this location is ideal as it can spray at the area where most solid waste might accumulate. The flushing unit does not spray directly at the tank sensors and at the area where the tank drains due to the tank design, although it might indirectly. The uppermost portion of black tank is partially covered by a frame, the most I can install it is about 3 inches from the top of the tank an inch shy of the flushing unit requirement of 2 inches.

4. Make sure you are 100% positive where to make the hole, this is a one-shot attempt and cannot be reverted. “No-Fuss Flush” device requires an inch diameter hole. A hole saw is ideal for making the hole because it captures the cut remnant, preventing it from falling into the tank.

5. Pre-fit the flush device, mark and drill pilot holes for the screws, and clean and lightly sand the mating surfaces for optimal silicone bonding. Apply a generous amount of silicone sealant (required) around the hole, firmly mount the flush unit, and secure it with three screws.

 

6. The flusher unit is connected to an elbow hose adapter and the hose is routed to the driver side of the RV where the remote flusher connection is permanently mounted. I applied J-B Weld PlasticWeld putty (though not necessary) around the edges of the flusher flange for added shear strength.

7. The hose is secured using zip-ties.

 

8. Fabricating the remote flusher connection mounting plate. The angle bar was purchased at a local hardware store. I used a Dremel with metal cutting blade to make an inch square cutout in the middle of the lower half of the angle bar for the water inlet. Using a bench vise and a hammer, I made an opposing 90-degree bend to the upper half of the angle bar to conform to the shape of the Sprinter lower "rails" where it's going to be mounted. The water inlet was riveted (x3) to the angle bar, then a 1/2 NPT pipe thread to hose thread 90-degree adapter is used to clear the gray tank which is located just few inches behind the remote flusher connector mounting location.

9. Remote flusher water inlet was mounted next to the holding tanks remote handle surround box using 2 rivets. A manual shut-off valve and a quick-connector with cap is used (optional) as pictured below.

10. Wide shot showing the city water inlet and the remote flusher water inlet.