Unclogging macerating toilet

The RV lifestyle can be very magical, traveling around the country, exploring the national parks and other interesting places.

Other times, things can suddenly go wrong, requiring time-consuming and/or expensive repairs.

One such not so super fun occasion happened recently, when the macerating toilet in our rear bathroom stopped working. It is a bit more complicated than a regular residential toilet; at the press of a button on the wall (actually one of two buttons, for smaller and larger flushes), it adds water to the bowl, pumps out the contents, grinding it into tiny bits and pumping it to the black tank, then adds more water to the bowl.

But while it happily added more water, the pumping out stopped working; it just made a little noise like it was trying to start, but nothing happened.

Fortunately, we have two toilets in our coach, so it wasn’t a disaster, but obviously not ideal. So I did some online research to see what would be involved in fixing it. When living in an RV, one has to be somewhat handy in doing repairs; there are mobile RV techs that will come to a coach to fix things, but they can sometimes be hard to find or schedule, and of course can be expensive.

(By the way, our mid-bath toilet works differently; it is a gravity toilet, directly above the blank tank, so just rotates a valve to flush the contents. It is still a bit more complicated than a residential toilet, using power to pump in water and open the value. I previously repaired a fault with that one, too. The rear-bath toilet uses the macerator to pump the content several feet to the tank.)

I found a few forum posts about this kind of issue with this model of toilet, but the most helpful thing was a YouTube video showing how to remove and disassemble the toilet. That showed me that it was something I could tackle. So I did.

Here’s the macerating toilet:

Macerating toilet

The buttons on the wall, and instructions under the lid (this was after I manually siphoned out the water):

Macerating toilet

The toilet is secured to the floor with a couple of hex-head screws on either side (sorry about the dust):

Screws

Behind the toilet, a glimpse of the several wires and pipes that make it go:

Wires and pipes

Wires and pipes

Here’s me investigating behind the toilet; I used this collapsable bucket and manual-pump siphon hose to empty it:

David

The pipes behind the toilet; the vertical one in the middle is fresh water going into the toilet, via a little pump visible at the bottom, and the other pipes go from the bowl to the pump, and from there to the pipe in the floor that goes to the black holding tank:

Pipes

There are multiple wires: DC power, a connection to the wall switch, and two sets of wires to the mid and full sensors on the black tank, so the toilet can show orange and red lights to warn that the tank is getting full (it refuses to operate when the tank is full). Those latter two had the same connectors and color wires, so I marked the plugs before disconnecting them, so I’d know which was which:

Marked plugs

That done, I disconnected the wires and pipes:

Disconnected wires and pipes

After removing the toilet, you can see the wires and pipes; the long wire is the DC power; the two tank sensor wires are also on the floor, and the wall switch connector is poking out of the wall, plus the blue water hose and the white sewer hose:

Removed toilet

The back of the toilet:

Back of toilet

I moved it to the shower, so any remaining liquid wouldn’t make a mess:

Toilet in shower

I then disconnected the pipe leading to the macerator pump, where I expected the problem would be (yes, wearing disposable gloves, and a head lamp to help me see):

David cleaning out toilet

Yep, there was an accumulation of non-dissolved toilet paper blocking the macerator:

Cleaning out macerator

We use Charmin Ultra Soft toilet paper, which is RV safe, as it quickly dissolves in water. Some people say only special RV-safe single-ply TP should be used, but life’s too short for uncomfortable TP. I’m not sure why some accumulated here over the past year of usage… but if I have to repeat this again in a year, it’ll be worth it.

Having cleaned out the blockage, I considered whether or not to further disassemble the pump, to look for any further blockage deeper inside, but it looked like I had got it all, so I decided not to. I moved the toilet over to the wall, and temporarily hooked up the power and switch to test it:

Hooked up to test

The pump ran correctly, so I re-installed it:

Repaired toilet

All better! Not the most fun job, but not too difficult. It is very satisfying to be able to fix something myself, and add more experience and a new skill.

I hope this wasn’t too gross for you. And hopefully this will help other RVers who have a problem with this model of toilet.