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Macerating Toilet For RVs: What Is It? Do I Want One?

Macerating Toilet For RVs: What Is It? Do I Want One?

We hear a lot about macerating toilet systems for RVs, but how do macerating toilets work and why would an RVer want one?

Today we’re looking at the macerator toilet and why some RVers prefer a macerating unit over a standard toilet system.

What Is a Macerating Toilet?

In most RVs, a regular toilet uses gravity to flush toilet contents directly into the RV’s black tank. (For more details on how a traditional RV toilet works, see our post “RV Toilet Talk”.) 

By contrast, a macerating toilet uses a macerator pump to grind & flush the waste. Because a macerator toilet uses a pump to send waste to the black tank, you can install a macerating toilet just about anywhere in an RV rather than directly over the black tank (which is where a gravity flush toilet needs to be located). In fact, some macerating toilets can send waste as far as 150 feet. 

Macerator toilets work in a similar fashion to garbage disposals. They grind up the human waste and paper flushed from the toilet and then pump that waste to the black water tank. Not only does this mean that you could install a macerating toilet almost anywhere in your RV, it also means that you could even add a second toilet if you’ve got a big enough rig (and access to a route for the plumbing, water, and power needed).

In fact, macerating toilets have become more common in RVs as floorplans have evolved. Rear bath and bath-and-a-half floorplans mean that the toilet may not be located directly above the black tank, so it can’t be a gravity-drop style “traditional” RV toilet. 

A traditional RV toilet with foot pedal flush

Traditional RV toilets have a foot pedal flush that gravity feeds toilet contents into the black tank below. Macerating toilets work differently.

Note that there’s a difference between a macerating toilet (which macerates right at the “source”, so to speak) and an RV macerator pump that connects to the RV’s sewer outlet and macerates the black tank contents to make it easier to dispose of using a smaller, longer hose.

How Does a Macerating Toilet Work?

The system that grinds up the toilet contents uses blades that are powered by a motor. That motor requires electricity to run. The blades liquefy the waste, which is then pumped through a pipe connected to the main drain line. Pipe sizing is generally ¾” to 1”. 

Most macerator toilets (sometimes called upflush toilets in residential applications) have two different flush buttons. One is strictly for liquids and the other is for flushing solids. 

The reason for this is that flushing solids requires more water to be used. So these toilets use a small amount of water for flushing liquids, but more water and greater water pressure to flush solids that have first been ground up by the macerator. This prevents any clogs that might happen in a system that’s moving solid contents through a discharge pipe and plumbing system.

What Are the Pros and Cons of Macerating Toilets?

As with anything else, there are pros and cons to macerating toilets. Let’s start by taking a look at the “pro” side of the pros and cons.

Advantages of a Macerator Toilet

Flexible Installation Location

Installing a macerator toilet offers flexibility with an RV’s floorplan because it doesn’t need to be located directly above the black tank. They’re also relatively easy to install. 

Lack of Odor

A macerating toilet system blocks direct airflow from the black tank when you flush. For this reason, you’re very unlikely to ever get an odor from this type of system.

More Traditional Throne

The actual toilet involved in a macerating toilet setup generally tends to be more like a traditional toilet in terms of form, function, and experience. 

The toilets tend to have porcelain bowls with elongated seats, and flushing usually involves pressing a button as opposed to a foot pedal and spray wand as is often found in RV toilets.

Clog Prevention

Because waste is liquified before ending up in the black tank, you’re not likely to get clogs when dumping. Preventing a plugged black tank is also important for the proper functioning of RV holding tank sensors.

RV tank sensors on a wall monitor

RV tank sensors can get gummed up by paper and solid waste over time. A macerating toilet grinds up solids before they hit the black tank so may be less likely to contribute to tank sensor issues.

Disadvantages of a Macerating Toilet

Now let’s take a good look at the “cons” of having a macerator toilet in your RV.

Higher Water Consumption

A macerating toilet generally uses more water and can deplete your RV fresh water tank faster, while filling your RV black water tank faster, too. If you tend to do a lot of long-term boondocking (like we do), this is an important consideration. 

More Moving Parts Involved

Because a macerating toilet has a motor and many moving parts, there are more things that can go wrong, and more parts prone to failure. 

Requires Electricity

The fact that these toilets require electricity not only means that you’ve got another “appliance” to power, but it also means that if your RV loses power or your batteries die, you can’t flush your toilet. 

More Expensive

Macerating toilets are more expensive to buy and replace than their traditional gravity flush counterparts. 

Toilet Sensor Can Prevent Flushing

Most macerating toilets have a sensor (or are tied into the existing black tank level sensor) in order to disable the toilet when the tank levels are too high. This is important to prevent overflow, but it also means that you can end up in a situation where the toilet won’t flush. There are workarounds for this, but it can still present an issue.

Popular Macerating RV Toilets

Now let’s take a look at a couple of the most popular macerator toilets for RVs.

Thetford Tecma Silence Plus

The Thetford Tecma RV macerating toilet

The Thetford Tecma is a wall-mounted unit that weighs just under 69 pounds. It uses a virtually noiseless turbine pump and is self-contained (meaning that it requires no external/separate pump or macerator). 

The Tecma flushes with the push of a button and has a sensor that indicates when your black tank is empty, half-full, and full. The toilet itself is made of a solid porcelain base and has a molded plastic seat and cover. 

Dometic Masterflush 8740

The Dometic Masterflush RV macerating toilet

The Dometic Masterflush has a flushing process that’s quieter and shorter than most other macerator toilets. To help with water usage, it also offers two levels of flush (normal or low). It’s a residential-style toilet of standard size and height and has an elongated bowl. 

Discharge fittings can run through the floor or through the wall, and flushing occurs with the push of a button. 

The Dometic Masterflush weighs only 41 ½ pounds.

If you’re interested in learning more about how a traditional RV toilet works for the sake of comparison, feel free to have a look at our YouTube video on the topic.

Do You Have a Macerating Toilet in Your RV?

If you use a macerator toilet in your RV, we’d love to hear about your experience. Drop us a comment down below!

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Gary

Tuesday 19th of September 2023

We have a 2007 Holiday Rambler Imperial with the Tecma toilet. It intermittently will not flush. Wait a few hrs and it starts working only to have the same problem again. Light is green and tank empty. The problem is getting worse and we can’t take it out like this. Any idea how to fix this?

Thanks, Gary

TheRVgeeks

Monday 25th of September 2023

Hey Gary... so sorry to hear about the trouble with your Tecma. We're pretty sure the Tecma toilets use their own sensor to determine the black tank level (basically, just a "Full" sensor, placed separately on the side of the tank). So, it's possible that there's build-up on the tank wall in the vicinity of the sensor, tricking it into thinking the tank is full, when it's empty. We'd suggest you may want to try doing a heavy-duty soaking to try and clean the tank walls and sensors (4 Ways to Clean Your RV Tank Sensors). If that doesn't do it, you COULD try searching for a black tank power washing service in your area. Or it's POSSIBLE that the Tecma's sensor is failing and needs to be replaced (though we'd pursue this as a last ditch effort).

Michael

Tuesday 5th of September 2023

Thanks for the great overview of these toilets. We like to boondock as well and are concerned about the extra water usage. We are looking to purchase a 2021 Dutch Star 4020 that has 2 of them. I know some motorhomes’ half bath is a traditional rv toilet that dumps directly into the black tank. We could then use that toilet while boondocking. However that’s not the case with this coach.

There are many factors to consider, but how many days can you stay off grid? Is the toilet the limiting factor? With our current motorhome and traditional rv toilet we can go for 2 weeks no problem. We’d like to reach that mark with the new coach as well.

I’ve read that people will flush with the water pump off and that may work some of the time, but not always! Any other thoughts from your real world experiences?

Thanks for your time and knowledge!

Michael

Tuesday 5th of September 2023

@TheRVgeeks, thanks for the quick reply. The toilets have a .8gal or .4gal flush option, so that would help a little. And the black tank is 7gal larger thank our current rig, so that would help some too.

My wife is a hard no on the composting!

TheRVgeeks

Tuesday 5th of September 2023

Hi Michael. Having two macerating toilets is definitely going to impact your length of stay in one spot while boondocking. How much it affects things will depend a bit on the difference in black tank sizes (is the tank size on the Dutch Star larger than what you have now?), how often you can not flush (i.e. #1 only) to avoid adding any more water than necessary into the black tank, and whether the macerating toilets have any option to go to a "water saving" mode to reduce the amount of water used per flush. Other than that, unfortunately there's not too much that can be done... other than removing one of the toilets and maybe going with a composting toilet? (nothing ends up in the black tank at all and it doesn't use any fresh water, either)

Werner

Monday 21st of August 2023

Hi! We have two macerating toilets in our Southwind MH and while they're convenient because there are no "pile-ups"; only slurry in the tank, one con for me was when the computer "thought" the tank was full, they wouldn't flush. First I blasted water thru the rinse port with the valve open and when that didn't work, I closed the valve & put about 10 gals of water in. Still no joy so I disconnected & drove around the park. Success for about 3 flushes. Added cleaner, water and drove to the next site & dumped. OK for 1 day. Googled the toilet & cut the sense wire & installed a momentary switch for emergency flushes. When I got home, I power-washed the tank and so far so good. The problem with having 2 macerators is no direct access to the tank.

Brett Potter

Monday 7th of August 2023

Brilliant review of the macerating toilet! I wanted to comment that I have in fact run my Tecma toilet in my 2013 Forest River Trilogy 3650 directly into the sewer without needing to use the black tank as a holding tank. I know this is very frowned upon in the industry (not closing the black tank valve) but it’s been a couple years and I have never had a problem with poop pyramid!

TheRVgeeks

Tuesday 8th of August 2023

Thanks for sharing your experience, Brett!

Tom

Sunday 6th of August 2023

We bought a 2022 5th wheel and it has a macerator toilet. We will never go without one again. Never an odor. Never worry about getting the dreaded "pyramid".

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