Upgrading from manual to electric toilet

[Gunner065]

Good day folks,

So after a comprehensive review and research of available electric toilets and space available to upgrade, I have settled on the Dometic MasterFlush 7160. Installation looks straight forward and I'll mimic the piping setup I currently have.

Although I'm pretty handy, the electrical component (e.g. adding a 25 amps circuit breaker, running the lines to the head and grounding) has me a bit puzzled, as I want this to be as safe as possible. I'm not worried about the piping and fastening the toilet to the deck, it is fairly straight forward.

Here's what I believe must be done, please correct me if I'm wrong:
1. Turn off all power and disconnect shore power
2. Gain access to the AC/DC Panel
3. Install the new circuit breaker in a spare slot and wire as per installation manual
4. Run a red (+) marine wire (10-12 AWG) from DC breaker to the head to supply power
5. Connect switch/toilet motor & macerator to the red (+)
6. Connect toilet motor & macerator to a new yellow marine wire (10-12 AWG) (-) and route/connect to the nearest 12 volt ground buss.

Or do you run a duplex electrical cable from the AC/DC panel to the head, use the red wire for (+) and use the black/yellow wire for (-), but where in the panel do you connect the black/yellow (-) wire to?

 

[DBBRanger]

What I did on my R25 was to tap into the wires going to to the black water tank macerator for power to the new head. They, on my boat, are located in the engine compartment right over top where I installed the head pump. I then added a switch near the raw water wash down switch to power the macerator. Thus, the existing breaker for the macerator is always on and the new switch is used when using the macerator.

Hope that helps.

 

[snydzy]

I wouldn’t bother running your power supply from the AC/DC panel..... it would be much easier to utilize The P.D.P (Power Distribution Panel) fuse block located underneath the port side hinged cockpit step.

 

[scross]

Our electric toilet is not “switched” at either the DC or AC panel. It is one of the “always hot” circuits like the bilge pumps, stereo, CO detector, etc.
I’d wire the new toilet to the house batteries directly or a main fuse block using appropriately sized wires and including a separate recommended sized inline fuse or resettable breaker. You don’t want the electric toilet turned off by turning off the rotary house switch in the cave so the connection needs to be on the battery side of that rotary switch.

PS: Here’s the 25 Amp breaker I installed for my solar controller. Easy to mount.
https://www.bluesea.com/products/7180/2 ... _Mount_25A

 

[FlyMeAway]

Are you plumbing the toilet to flush with fresh or salt water?

Moving to an electric head is a good time to re-plumb to fresh, if that's your thing. Or, I can recommend what I did on my last sailboat -- installed a system that allowed an option between salt and fresh (this was integrated into the toilet, so not sure if Dometic has a model that includes that).

If you end up re-plumbing to fresh, I *highly* recommend the electric toilet be on the same circuit as your freshwater pump (this is how my R-31CB is set up, too). That way you can't accidentally flush with the pump off, which can create problems!

 

[Gunner065]

Thanks all for the great recommendations.

As a side note, since we spend a balanced amount of time on the hook, we decided to keep the raw water flushing. Never had any issues with smells as the previous owners installed a "Big Orange" filter on the Holding tank vent outlet.

After having a closer look at the boat today, I have decided to follow snydzy's advice below.

I wouldn’t bother running your power supply from the AC/DC panel..... it would be much easier to utilize The P.D.P (Power Distribution Panel) fuse block located underneath the port side hinged cockpit step.

I'll post photos on completion of the install, as I'm sure others have thought about making the move to electric, but just haven't got to it yet.

 

[Wolfboy]

I have a 2008 R25 and the admiral would love it if I changed out the old Wilcoxen for something like this. The 7160 model is the residential (I take it that means larger) model as opposed to the compact versions these boats came with, correct? Any concern with space in the head for a larger toilet?

 

[Gunner065]

I have a 2008 R25 and the admiral would love it if I changed out the old Wilcoxen for something like this. The 7160 model is the residential (I take it that means larger) model as opposed to the compact versions these boats came with, correct? Any concern with space in the head for a larger toilet?

Wolfboy, based on measurement I took with the Manual Jabsco still in place and comments from other Tugnutters, the Dometic MF 7160 fits in that small of a footprint.

We started the install a few weekends ago. Unfortunately, I had a few questions regarding the installation requirements that I sent to Dometic and their answers were not helpful.

As an example, the wire gauge they recommend for a 25ft (total) run for a 25 amps circuit indicates a 10-12 gauge wire. In accordance with ABYC guidelines, this arrangement would provide for an 8% voltage drop. My research shows that for pumps/macerator to run at peak efficiency, the voltage drop should be no more than 3%. As such, and to be on the safe side, I ran 6 gauge wires from the cockpit port lazarette power distribution panel (fuse block) to a power post under the sink.

The 7160 provides a higher "residential" seat and uses raw water for flushing. As we very seldomly take showers in there and because I hate sitting on the deck when using the heads (I'm 6'3"), we decided that a more comfortable toilet that might occupy a bit more room than a more compact one, made sense to us.

Although the sales rep told my wife that the install would be "plug and play", nothing in a boat is ever plug and play. The plumbing will be a challenge to make it look good, but we'll get there. I'm documenting the install and will post pictures to my album over the weekend.

 

[Gunner065]

A bit of an update folks,

Dry fitted the MF 7160 in our head yesterday. The base fits well and the lid/seat open fully. The "residential" seat does occupy more room than the compact one, but in the end, for us it's worth it. (it's not like we spend a lot of time in there anyway)

Instead of re-using the current plumbing and using adapters to make it work, I will be changing the plumbing lines with Green Line G380B-150 hoses. These hoses allow for tight radius and are easier to work with than what is currently in the boat. Yes, they're not cheap, but is anything cheap on a boat?

Like a friend of mine (marine tech) said: Spend the money, do it once and have piece of mind.

 

[Gunner065]

Another small update.

Decided to replace the hoses. Started with the sewage hose. Because of its rigidity, I decided to cut the hose in the stabd lazarette, then pull that end from the head.

Although the boat is only 10 years old and averaged 50 hours on the engine a year, the sewage hose's inside diameter was severely restricted by "left overs". Insight being 20/20, I now recognize that anytime replacing any component that uses a hose for its inlet/outlet, one should replace the hoses as well, so as to have piece of mind that all is fine.

Next weekend, pictures, finalize the plumbing and advance the electrical connections.

On a side note, which tools is best to neatly cut fiberglass with?

 

[snydzy]

On a side note, which tools is best to neatly cut fiberglass with?

I get really good results using a HSS blade on an oscillating tool. Easy, accurate, and gets into some tight spaces.
Second choice would be a good old fashioned jig saw...

 

[FlyMeAway]

On a side note, which tools is best to neatly cut fiberglass with?

I've used a Dremel before, especially for very small cuts, basically with a routing/cutting bit. Start with a pilot hole. It works pretty well, but need to be careful near the end (and also move in the right direction!).

 

[Gunner065]

Update # (I lost count),

Wife and I are still married, so I guess it's going good. Sanitation hose in place, the white hoses installed at factory are out (had to cut them at random points to take them out, as the shape of them was set).

Attempted to pass the new raw water hose, to realize that both hoses (sanitation and supply raw water) won't fit in the existing hole. New hole required on the floor where the toilet will be mounted. The floor is composed of Gelcoat/Fiberglass/Plywood (totaling approx 1 inch thickness). Today will hole saw a new hole, pass the raw water hose and potentially hook the toilet to the hoses/boat.

Of note, if you're a new boat owner and your spouse is either not a mariner/mechanically inclined, tamper her expectations about the reality of upgrading systems around a boat. Apparently, since I wasn't listening to that conversation, the rep at the marine supplies store, told my wife that the Dometic MF 7160 would be "plug and play" with the hose configuration of the Jabsco Manual Pump toilet. I knew from the start that it would require some modifications, she did not. Too late, already sold the pump toilet...

Don't get me wrong, RTs are well designed/built, but there isn't a lot of room to work in there for a 6'3", 250 lbs kinda men. Oh, yeah, latest tool purchase: electronic inspection endoscope. Allows you to see in every nook without having to take bulkheads off. Get yours today.

 

[scross]

A word of encouragement here. Once you are done with the install I’m confident you will enjoy the upgrade.
If there are any hoses that you were thinking of replacing but couldn’t reach, I’d recommend a hose cleaner brush like this:

SLSON Aquarium Filter Brush Flexible Double Ended Bristles Hose Pipe Cleaner Stainless Steel Long Tube Cleaning Brush for https://www.amazon.com/dp/B07CJ4NW7H/re ... UTF8&psc=1

I used one like this on my old Monterey 242 Cruisers fresh water hoses to get out mold in the lines (along with bleach) and it worked pretty well.

 

[j&lgray]

I had replaced the electric Jabsco toilet with the same Dometic, Orbit, model 7160 in our R-27 while cruising on the Erie Canal. The electric Jabsco is no longer made and no wonder because it had an engineering flaw: the macerator function was driven by a belt. When the belt broke, I quickly found out that no one, anywhere had it. The wonderful folks at Marine Sanitation in Seattle confirmed that the belt is not available, that Jabsco's re-build kit is hard to get, and replacing the whole toilet was the best option. The Dometic like the Jabsco uses sea water and the source of the sea water is shared with the Yanmar engine. I also quickly found out that that the engine uses all the sea water coming through sea strainer, leaving none for the Dometic head. So, we adapted and used fresh water while underway by filling from the faucet/shower combination.

Fast forward three years, the impeller in the Dometic failed from all the "dry" use. I converted the Dometic to use fresh water, thanks again to Marine Sanitation who had the right part, an electric solenoid value, and the advice on how to do the install.

 

[Gunner065]

Thanks all for the comments.

At first, I was like: let's save myself some pain and cost, let's not replace the hose. After recognizing that I would require fittings and more hose to make it work, I decided to replace all the old hoses by new ones. As well, I punched a hole through the deck and relocated the inlet raw water hose, for aesthetics and ease of connection. After some probing, using a digital endoscope, I noticed that there is 3/4 plywood under the platform on which the toilet sits, making mounting a new toilet very secure.

Plumbing is now done, onto the electrical next weekend. Pictures to follow soon on my album.

 

[Gunner065]

Happy Sunday afternoon fellow tugnutters,

So the toilet is installed and works like a charm. The dometic MF 7160''s seat is higher and more comfortable than a compact toilet. The current plumbing configuration in a 2010ish R25/27, must be adjusted, but it's worth it in the end. The orbit base, which separates from the bowl, made the installation that much easier. Thinks I learned along the way:

1. These boats are well designed and built to enjoy from day one. They were not designed for easy retrofit as access to existing plumbing/electrical can be tricky to get to. Solution: Digital endoscope.

2. If replacing any sanitation device (especially if you're not the original owner), do yourself a favor and replace all hoses/fittings/hose clamps. Might seem like a lot of work and expenses at first, but will save you headaches and costly repairs at the most inopportune time (usually away from home port).

3. When reaching out to Dometic, I expected to get straight answer to very clear questions. Their reply didn't bring any clarity whatsoever. So I fell back onto ABYC guidelines, which recommends less than 3% voltage drop for wiring of pumps. As such I wired 6 AWG tinned wires from the power source to the toilet's switch and from the switch to the ground bar. Overkill you might say, but for the extra cost, I have piece of mind. Plus, if you drop 1-1.5 volts at a smaller AWG, your macerator might not last/work properly.

I did mentioned that I will post pictures, and I will, most likely later this week.

Finally, for anyone out there thinking about doing the swap to electric, do it. You'll need an "assistant" to run the wires/hoses, but aside from time and money, I would rate this job a 3/10 for difficulty (anything 8/10 and above, in my book, should be completed by professionals).

 

[Wolfboy]

I'm looking forward to your photos. I'm curious if the layout of the 2010 R25 SC is the same as the 2008 Classic. That would go a long way in helping me decided on brand and size of toilet to get.

 

[PanaSeaAh]

Ditto that.

 

[Gunner065]

Evening folks, just uploaded pictures of the finished upgrade and associated plumbing/electrical.

Enjoy