[jdkskyking]

Okay, I want to make sure I’ve got to his straight. I’ll include two pictures to ensure I’m on the right track. It’s part of my effort to winterize the coach. I’ve already run antifreeze throughout the system.

Picture #1- I’ve labeled the two sources that can flow to the sewer system (or ground).
Picture #2 - The Main Dump Valve (usually air activated).

Dumping the waste holding tank utilizing left side plumbing bay:

Remove coach sewer pipe cap, attach sewer hose (slinky) to the connector next to the Main Dump Valve. 

Manually open the waste tank valve (in pic #1 the valve appears to already be open).

Activate Main Dump Valve to drain waste holding tank.

To rinse tank hook water hose to tank flush spicket in aft area of Aqua-Hot bay. Rinse until solids have moved through sewer pipe. 

Allow tank to thoroughly drain before closing valves. 

Run RV Antifreeze in sinks to allow antifreeze to enter holding tank via grey water pipe system.  Flush toilets to allow antifreeze to enter waste area of holding tank. 


If I understand the system this will also winterize the holding tank. 

Thanks, JK

[77newell]

If I dumped the holding tank prior to starting winterization I don't bother with any further dumping following winterization. The water remaining in the tank has lots of room to expand without causing damage. By itself, water freezing isn't a problem unless confined.

[pairodice]

If the tank is full of waste will the ‘heat’ from the waste keep it from freezing? I’m worried about my coach sitting near Dallas, TX...

[Fulltiming]

Doubtful that the 'waste' in the tank would be active enough to generate much heat over an extended period of time. You would be better off dumping the tank before storing it.

[rheavn]

First hand experience. A full black tank will freeze solid as a rock.