I knew when we bought our new fifth wheel that I would eventually have to do something about the holding tank plumbing. I also knew that a Drain Master electric waste valve was going to be a key part of the makeover.

Our Coachmen fifth wheel bunkhouse floor plan was designed with two toilets, one up front and one in the rear. Apparently Coachmen couldn't figure out how or didn't want to spend the extra money to plumb the two together and instead we had to have two sewer hoses going into a 'Y' fitting at the sewer hookup. It was a real hassle and required carrying double the amount of sewer hose which was difficult to stow.

Drain Master Waste valve from Phase Four Industries.

The front holding tank drain before the upgrade.

But that wasn't the worst of it. To connect a sewer hose or operate the valve on the front holding tank we had to get on hands and knees and crawl under the trailer to reach it! That wouldn't be fun for a young person but for a couple of old folks it was literally a pain. We had to live with it for about six months.

It took me that long to figure out what parts I needed, how to do it and for the weather to get better but I finally got time to do some plumbing. The Drain Master electric waste valve was the perfect solution. We're really happy with the way it works and recommend it to anyone.

Now once you start looking at the photos below you'll see a couple of things that may concern you. Yes, I had the same concerns:

1. The pipe going to the back seems really close to the axles.
2. There is no slope to the pipe for proper drainage.

As close as I can measure, even at maximum travel the axles will not hit the pipe. The pipe will be dry when we are traveling so even if it does get damaged there won't be a mess to clean up.

As for no slope, it hasn't been a problem for the few months since it's been installed, but as you can see in the photo, I included a standard bayonet sewer hose connection in the new system. Normally it will be left capped but if that long pipe ever gets plugged I can use the connection to dump the tank and I have an access point for a cleanout snake.

The new front holding tank connection. Notice the capped sewer connector that doubles as a cleanout if the long drain pipe ever gets clogged.

View of the new holding tank drain system from the back of the trailer. The 'T' ties in the rear black tank which has it's own gate valve.

The new sewer connection doesn't look too much different from the old one. I salvaged the original valve assembly which is why I have 'extra' 3" valve... you can see the black tank valve handle peeking out under the sidewall. But the extra valve may come in handy when we're boondocking. Since the front holding tank is a combination gray/black tank it tends to fill sooner than the rear black-water only tank. With the third 'extra' valve closed it will be possible to open both holding tanks valves allowing us to balance the capacity. Plus we will gain the extra volume of the long front-to-back drain pipe. That should give us one or two extra days before we have to find a dump station.

You may also notice the rubber couplers. They serve two purposes: 1) to compensate for my poor plumbing skills and 2) to allow the long front-to-back drain pipe to be removed easily when I need to gain access to the underside of the trailer.

I wanted the switch that operated the Drain Master waste valve to be back where the other valves and the sewer connection was. I used 14 gauge automotive wire run in plastic wire loom. A weather proof outdoor 120v receptacle cover was used to protect the switch. I couldn't find a smaller cover so there's room for another switch or connector if I ever have the need. When pressing the switch, the Drain Master makes just enough noise to reassure you it is working.

Installing the Drain Master waste valve was the easiest part of the whole project. If you have a hard to reach valve handle... even if it's not as bad as mine was... you may want to consider replacing it with a Drain Master. If you are just a little handy, you can do it yourself. Phase Four Industries' Drain Master kit has all you need to replace an existing manual valve and the instructions are complete, accurate and easy to follow. No special tools required.