Saturday, December 3, 2022


A macerator pump can resolve your sewage issues


By Jim Twamley

Shanghaied by sewer problems? What’s that? Want to stay on a relative’s property in the comfort of your RV but can’t because your holding tanks won’t let you? Want to stay at a pristine campground for more than a few days but can’t because your holding tanks won’t let you? Perhaps it’s time you purchased a macerator.

Macerator pump

A macerator pump connects to your RV sewer drain. You open the drain valve and turn on the macerator. It chews up the sewage with blades (kind of like a blender) and then sends the small particles out a garden hose. These characters are versatile — I’ve used mine as far as 150 feet up a small incline. I use it to empty both the black water and grey water tanks. This allows us to stay at campgrounds that do not have full hook-ups for longer periods of time.

Using a macerator pump isn’t as convenient as full hook-ups, but it is much faster and more efficient than using a blue boy. The trick is to park close enough to the dump station to do this. I’ve also run the hose into a bathroom window and down into the toilet — it works great! Most of these units operate on 12 volts DC.

Editor’s note: Check out the selection of RV macerators on Amazon.


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2 years ago

It seems a lot of people are jumping on the “macerator train”, and in looking at the system, I am a bit perplexed about the overall advantage. Is it that you don’t want to go to a dump station, or you are somewhere that there is only a (vault) toilet, or something other than normal? Most people today, in RV’s have units that have pretty good size holding tanks (ours is 50 gallon of black and 60 of gray). The capacity of these tanks generally outlast the time at any one place, allowing for a pass through dump station to release. Plus, do I want to carry another 100 – 150 feet of specific black water hose with me and fight that every time I want to reduce tank volumes? Maybe it is just me, and I do not see the overall advantage of having a macerator on board as something you need vs nice to have. It seems this is more advantageous for “at home dumps” into septic systems than anything else.

2 years ago

We try to travel the road less travelled so when lucky enough to do so have only rarely wait in line to dump.
Plus we get about 50% more time out of our system since we only rarely shower in our rig or use this precious resource in ways we see many folks downright wasting it. We regard water as the most precious essential resource on earth and treat the usage of it accordingly.

Although never having had a macerator pump on any of our units, which in some cases could be (and arguably is) the cats meow, I still think over all nobody will ever invent anything like the cam lock Waste Master system which we have aboard our current rig.

Thank you Mr. Twamley for the article, another reason this newsletter is so valuable.

2 years ago

Having a macerator means I never have to wait in line at the dumpsite. If I’m within 300′ of ANY dumpable destination, I’m good to go. If I really haven’t been able to dump during a stay, absolute worst case, I bring the tank home or to the next destination where I CAN pump.

One trick no one seems to be telling people — if you’re using a standard toilet as your destination, you shove your garden hose THROUGH the trap, not just into the bowl. This will make your dump totally odorless, as opposed to being shot on site by your host if you run 50 gallons of fermenting black tank “open air”… Thereafter, pump out your black first and grey second as always, and your hose itself shouldn’t smell.

2 years ago
Reply to  Wolfe

BTW: THIS experience, a true story, is the LAST time I waited in line more than a single RV… and a macerator gives you the option to not follow people who spill, too… 🙂

2 years ago

I find the macerator very convenient to dump at home if I’ve been parked where there is no dump. No matter how much you flush so the blades are clean, there’s still a bit of gunk that tends to bind the blades the next time I use it and blows the fuse. So, each time I want to use the macerator I take a pair of long nosed needle nosed pliers and turn the blades to make sure they’re loose. Haven’t blown a fuse since.

2 years ago

I used one of these when I stayed about 3 months at my son’s house. I hooked 100′ of 3/4 garden hose to the pump and then to his sewer clean out. It worked great! It wasn’t as convenient as a sewer drop at the trailer but, it beat having to hook up to the trailer every week for a trip to the park’s sewer dump!

Joe Allen
2 years ago

We have and use the Sewer Solution at our son’s home and where we need it. I am pumping right at 55 feet with 25 feet of the Sewer Solution and into 3 10foot sections of 11/2 inch PVC. Have not had any issues with this setup. I also used this same setup back in 2005 at our sister in laws home and again, was impressed on how well it worked.

2 years ago
Reply to  Joe Allen

Years ago when we were full-timing, I also used the Sewer Solution and PVC when staying in my wife’s parents’ driveway. Worked great.

2 years ago
Reply to  Barry

I believe SS is the water-propelled venturi??? If so, it’s pretty BAD if the recipient is on a septic field, which is not made to SUDDENLY accept 50gallons of black tank plus 30-50 gallons of extra propellant water. You overrun the sediment tank and push solids into the leech field, damaging the whole system.

2 years ago

Why not just install a Thetford SANICON Waste Extraction system. Certainly would be a heck of a lot nicer than draping a pipe thru your window into your black tank.

Bernie Turner
2 years ago
Reply to  Rick SORRENTI

The hose is not going in your RV toilet via the window but into the toilet you are dumping into ie at your relatve’s house.

2 years ago
Reply to  Rick SORRENTI

The macerator pump attaches to the the waste system outlet, just like your normal waste hose does.

2 years ago

There are also major downsides to macerators! When we bought our 8 year old Country Coach, I noticed it had a macerator, and questioned why I’d want it. The tech told me I’d learn to love it, and not to worry. Well, the second time I used it I noticed a small leak at the connection of the macerator and the tank outlet. So I pulled it off and greased up the connection, the o-ring that keeps it sealed. What I didn’t notice was that there was a hairline crack developing in the “fingers” that hold it on to the pipe. Next time I dumped, that cracked finger failed, precipitating a total failure of the connection and in an instant I had a 3″ black tank outlet pouring sewage. Of course I jumped into action and shut the valve, but not before getting the proverbial “sh*t shower” and dumping several gallons of the stuff onto the ground alongside the dump fitting.
PS: make your life with gravity super easy by fitting a terminal valve to your tank outlet. It’ll keep the odd drips out of the cap, and gives you total control of the dump process. Plus – you can flush your black tank with grey water, which is much more effective than the internal fresh water flush device.

Tommy Molnar
2 years ago
Reply to  Don

When we got our new 2012 trailer back in 2012 I noticed there was always some ‘drip’ behind the outside cap of our dump system. Warranty got the black valve replaced once, but it continued to leak. When we went to the factory for some other repairs we told them about the drip problem. Their solution? Add an outside valve just behind the cap on the dump pipe. Problem solved!

I’ve given the macerator device some thought, but so far, haven’t gotten one.

2 years ago
Reply to  Don

SO many things wrong here… First, obviously, your macerator is installed wrong. You do NOT mount the bayonet-style pump permanently. On mine it would be stupidly bouncing down the road if I did that. Macerators are either bayonet mount temporary (only when pumping) or installed permanently in a bay, using flexible piping.

Yes, you grease the gasket occasionally if you want a perfect seal. Of course? I’ll admit I don’t grease mine often, but it doesn’t leak.

No, DON’T flush your black tank with your grey. Early on, I thought that was a good idea too, but it results in backing up sh*t into all your grey drain plumbing, spreading “ick” inches from your kitchen sink. ALSO, using your grey to flush your black tank only reaches 50% when the volume is split. ALSO, having used your grey tank this way, you don’t have it to flush out your drain line correctly (letting the soapy water help clean your stinky-slinky instead of “finishing” with 50% sh*t).

As for terminal valves, not my choice… I have the cap with a garden-hose fitting, for those times when it’s OK to drain excess grey into a pit (there are rare times, yes!). Because of this, I open the little cap while holding my waiting 3″ hose underneath. If no dribble, I take off the rest of the cap and connect. If there’s MUCH dribble, replace your upstream valves properly.

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