Macerator Toilets

[slabman]

My 2014 Essex came equipped with two Dometic 8759 macerator toilets, plumbed into a 45 gallon black tank. First two days resulted in a full tank, which did indeed surprise me. So what to do?

Dometic claims to have two flush settings, a 0.85 gpf and a low volume setting of 0.45. So I did some flow testing and found these rates did not vary by much, no matter the setting. I got flow rates in the range of 1.1 to 1.15 gpf, so close that I couldn't identify what setting I was on, but clearly in excess of what Dometic is advertising. After playing around with the Manablock I was able to screw down the toilet fill flow rates to about 0.75gpf, depending on how far I turned down the water flow. The amount of toilet water fill is a timed event, so a lower flow rate will fill the bowl with less water.

After calling Dometic I learned of a setting Change I could make to the toilet control module. After flipping a dipswitch and turning the Manablock to a low vol setting, I was able to get it down to a liter per flush, although due to the "wier"feature of this toilet, there isn't quite enough water available to completely clean the bowl....adding just a second or two of additional fill would do the job, so long as it isn't a BIG job, so to speak! VBG! In that case, more water will be needed for sure. I understand Dometic is coming out with a new model of this toilet this summer which will eliminate the weir design in favor of a direct drop into the macerator blades. This new unit is said to reduce volumes to less than a liter per flush. I only did this mod today, so do not know what my results will be, but will post after I fill the tank, hopefully? In more than a week?

Now another problem I need to solve involves the toilet shutting down at the 70%full tank mark. I'm told Newmar uses a Dometic float sensor which shuts off power to the toilet at 100% as read by the Dometic sensor but at 70% as read by my Silverleaf tank monitor. But after hitting the 70%level, I can flush perhaps 1-2 more times and the Silverleaf readout jumps 30 points to 100%! (Mod Edit) So I haven't been able to get Newmar to tell me what's going on here and what sensor is reading what. Again, very frustrating, since With this tiny tank I surely don't want to leave any tank capacity on the table. Will post when
I get to the bottom of this.

[Dutch Star Don]

Slabman.....we tried out our new Dutch Star this weekend and played with the toilets. I had read your previous post and knew about the two water settings. I changed them several times and like you said, it's almost impossible to tell the difference. The lower setting seemed to not fill the bowl as much.

I don't have a Manablock, but I will check for a shut off valve at the back of the toilets and maybe turn them down. Where is the dip switch you located.....on the toilet?

My red light came on both toilets after just two days. I checked the tank monitor and it said the tank was 2/3rds full. This could be an issue when boon docking. I was about to toss the blue tank that I never used on my previous coach that I had hidden atop the fuel tank. I'm rethinking tossing it!

["007"]

To have two toilets off the same 45 gal holding tank is stretching it pretty thin in my book I think its some thing Newmar will have to look at in the future.
My bath and 1/2 has a 45 for rear toilet and a 45 for the front toilet which the sink also drains into.
The 45 rear is wiped out because the engine is back there.
We are in the situation as when you may have had a class A and finding out your toilet, sink and shower entered into the same tank.
No body tells you this until you find it out after use.

[RV4Me4Life]

Hello "slabman",
You may need to have all three of your tanks re-calibrated. I just picked up my new 2014 Mountain Aire 4369 from Tom Johnson Camping Center, Concord, North Carolina, and found out that the tanks were not calibrated correctly. A qualified service tech needs to go into the Silverleaf system and reprogram the black tank. I think this may help solve your problem with fast fill issues - at least you will have accurate data on the Silverleaf system. The freshwater and water tanks were also recalibrated while he was in the system. I believe you call the tanks before we calibration was accomplished. Newmar will pay for this as part of the warranty. I always empty my gray and black water tanks prior to departing camping grounds. Congratulations on your new coach purchase.

[RV4Me4Life]

[QUOTE="RV4Me4Life;1934116"]Hello "slabman", ...]

Please excuse all the typos. You can see that I wrote my note to you in the early morning hour. Nevertheless, if you read between the typos, my message should become obvious to you.

[YC1]

Interesting issue. Is there no feature for a dry flush? Different model in my rv but it has two buttons. One is a low water flush, the other a higher level, and if you press both it will flush with no water.

["007"]

A dry flush with the macerator system will not work because one toilet has to move the ground up items through a 1 1/2 inch pipe to the holding tank.
For people with non-silver leaf or E-Plex systems there is calibration info in QT's 1 & 2 for both the other two systems Newmar uses.

[slabman]

No Manablock? I think I'd install a valve at the rear of the toilet. Easy to remove the bowl and you'll find a common 1/2 in line. The 1-1/2in. waste line is connected to a moderately flexible line coming up from the floor. Just loosen the worm clamp and these lines will separate and you can lift the toilet off. I'd think a conventional shutoff valve as used in domestic toilets would plug and play-HD has them, of course. Play around with this 'till you get a low enough setting to do the job.

There will be a 4x4 in. Black plastic control module within about 6 ft. Of the Dometic toilet....I was able to find the rear one on the closet side wall nearest the toilet. But I still can't locate the half bath module. Just pry the back off and look for a baby blue-colored little box on the board, containing two dipswitches. The left one needs to be flipped down, not up as it was originally set. The right side switch isn't used ( it has several numbers on it) So I flipped the switch down and tried the toilet. I found it was necessary to turn the Manablock flow rate up to max, but still it is marginal for flushing yellow liquids only....toilet paper won't flow over the weir unless you do about a 1-2 second fill before flushing. But at this setting my flow test used only one liter.....awesome! A little more if you have to add a little more water to the bowl.

Don, see what you think of this and let us know. It just may be you'll be able to reduce water flow sufficiently by just adding an in-line water fill valve. Besides, you'll need something else to do after finishing up the other 1000items on your to-do list. LOL!

I honestly thought I'd get a blue tote, hook it to my Lexus and park next to my Essex and take a picture to send to the brass at Newmar. Could even post it online, I suppose. Might get some response, dontcha think? But, seriously, I also think it's irresponsible to install TWO macerator toilets and not increase the tank capacity. I don't buy the weight excuse since we have increased front end allowables over what we used to see. For example, my TS had a 60 gal black tank with a 14,400# front axle. These coaches have gained significant amounts of weight in the past 5 years, so a few more gallons of black wouldn't break the bank. Anyway, how embarrassing it would be to be seen filling a blue tote from the belly of a high-end motorhome like these.

["007"]

I have moved this thread to QT's # 3 filed under toilets and Don's mod section maybe Newmar will take notice of the problem with only 45 gal tank.

[slabman]

RV4ME. Yes, i do need to get the tanks re-calibrated, but that won't add a thing to the capacity. I say this because when my Silverleaf reaches the 70%mark, it shuts down. I did sever a yellow wire leading to the toilet control module at the rear one, which allowed unlimited flushing. But after a couple more flushes the readout jumped to 100%and I could hear some rumblings of fluid in the half bath toilet, indicating the black tank had reached the full level and any more liquids "added" by the macerator would end up coming out of the vent stack on the roof! Ask me how many time that happened with the other coach! :-)

[wa8yxm]

Two things.. First, the amount of water in the bowel depends on the line pressure.. If you are NOT using a pressure regulator, you may need one (A good one like a 1/2 inch Watts with proper adapters) set to around 45-50 PSI (Try to match the water pump on the RV for simplicity.

Second... My macerator has a knob, turn one way for more, other way for less.

[smlranger]

Welcome to the world of macerator toilets . When we first got our Allure with the Tecma toilet (we only have one), we were really surprised to find the red light on and the See Level system showing our tank nearly full after 2 1/2 days. This was compared to easily 5 days (or more) on our Journey with standard Thetford toilet.

Our Tecma allows you to adjust the amount of water left in the bowl but not the volume of water used for the low volume vs. high volume flush. I do use a water pressure regulator so that seems to help a bit controlling flow.

What we have learned to do is 'flush management,' especially when 'dry camping' at a relative's home for up to 4 - 5 days. We generally will not flush until there have been 3 'liquid deposits.' Last time at that location, See Level system was showing 70% full on day 5. We can live with that.

[slabman]

WA8: When you say "macerator" I assume you do mean the toilet, as opposed to the macerator discharge system down in the basement. Not sure that this knob might be. What brand/model toilet do you have and where is this knob?

[Dutch Star Don]

I went out today and looked at the full bath toilet. There is a flexible hose on the toilet connected via threaded fitting to the coach plumbing. It would be pretty simple to add a shut off valve. This would also add some protection in case of a toilet breakdown. The wiring disappeared down into the floor which is above the DEF tank. Who knows where the black box is.....maybe in the ceiling of the slide out bay where they put everything else.

One thing I didn't check the other day....when the light goes to red on the wall flush button, does it still flush? I didn't try again and just dumped the tank.

We've been spending Thanksgiving the last 20+ years camping in Yosemite Valley. We started off with a Jamboree Class C that required many water hauling and blue tote trips (different containers ) over 4 days with three women in the coach. Graduated to a Class A gasser in 2004 and then bought our Diplomat in 2005. I sure hope I don't have to go back to the blue tote again after 10 years.

I guess will do like the Fockers.....if it's yellow let it mellow....if it's brown, flush it down!