Strange Things in Your RV Macerator Pump

 Strange Things in Your RV Macerator Pump

The dreaded green hose.

We recently underwent an RV maintenance/repair crisis which thankfully was resolved happily, but holds a lesson or something for all RVers. Let me tell you the story and you’ll see what I mean.

OLYMPUS DIGITAL CAMERA
This is the manifold which connects the gray water tank (top), the black water tank (bottom), and the macerator pump (left). The emergency dump is the plug on the right.

First a little dreary technical background -for the past ten years or so, Roadtrek and some of the other Class B manufacturers have been including a pump in their wastewater systems called a macerator. This pump liquifies and pressurizes the contents of your wastewater tanks and discharges it through a one-inch hose, the advantage being you no longer have to wrestle that three inch diameter anaconda of a gravity hose, and have a little more assistance than just gravity to help you empty all the contents of your wastewater tanks. The disadvantage, in addition to having one more part to break, is that any strange objects which find their way into your wastewater tanks may jam up the blades on the pump.

We have had our fair share of such strange objects in the seven years of our RV adventures. Every time I disassemble this mechanism and discover hidden treasures, I review them with my lovely wife and cat to see if we can figure out how they got there. The cat consistently denies all involvement, which narrows down the list of suspects considerably. Candy bar wrappers, hair ties, etc… somehow they fall out of pockets or otherwise find their way down the toilet and into the plumbing. We all renew our vows of diligence and caution, and it works OK for a while, until it stops working again and we repeat this cycle.

Here it is installed in a Roadtrek. The macertor pump is behind the sheet metal shield, and the plug is at the bottom of the photo opposite the pump.
Here it is installed in a Roadtrek. The macerator pump is behind the sheet metal shield, and the plug is at the bottom of the photo opposite the pump.

Now, I’m no saint myself. Early on I was standing over the toilet with a hose flushing the tank, with my keys in my hand, until suddenly I didn’t have my keys in my hand, and I watched horrified as they disappeared down the hatch. I eventually got them back, one by one, as the key ring rusted, but it was a long and tedious process, during which my macerator pump made funny noises. Hey, I can relate when people say, “I just don’t know how it happened.” Trust me, I’ve been there.

Which brings us to our latest episode of strange objects in the wastewater system. To her credit, my beautiful bride dutifully informed me that a plastic dental cleaning device about two and a half or three inches long had somehow found its way into the wastewater system. She saw it too late as she flushed the toilet. Now, in her defense I have to say this was unintentional. The dental thingie was lying around in the bed and had somehow gotten stuck to her skin in a bodily region which decorum requires me not to specify in too much detail, but suffice it to say that it *cough* ended up falling into the toilet in the course of her activities.  Oy. It looked like I was going to have to do major surgery on our two month old Roadtrek to retrieve the prodigal pick.

The dreaded green hose.
The dreaded green hose.

But then I remembered – on the new models, there’s an emergency dump plug directly across from the pump which allows you to dump. Maybe there was some way to get this plastic pick out without tearing the whole thing apart.  I dumped the tanks using this emergency dump, and beamed a flashlight into the area I could see through the plug hole -no luck.  Maybe a gentle back flushing by running water back up the green discharge hose would help?

I carefully turned the water hose on to a moderate flow and held the hose to the end of the green hose, leaving the emergency dump plug loose. This system is not meant to have more pressure than the wastewater pump generates, so don’t clamp a fire hose onto your green hose, turn it on full blast, and say I said it was OK. It isn’t. We are talking about gentle water pressure here. Think of it as colonic irrigation for your RV. Get too enthusiastic and you’ll feel a sharp pain – in your wallet. The impeller and other components won’t react well to excessive force.

On the right is the dental appliance I'm talking about- a plastic handle with a little brush at the end. On the left is the one that made a fateful voyage through our wastewater system, taking a few whacks from the macerator blades in the process.
On the right is the dental appliance I’m talking about- a plastic handle with a little brush at the end. On the left is the one that made a fateful voyage through our wastewater system, taking a few whacks from the macerator blades in the process.

I promised you a happy ending, so to speak, and sure enough after a couple of gallons the offending article made its appearance in the rinse water coming out of the emergency dump.  The macerator pump works great now.  My wife and I couldn’t be happier.  We have once again resolved to be vigilant in our efforts to keep strange objects out of our wastewater system, and to check our six before any maneuvers from now on. Wish us luck.

campskunk

"campskunk" is a blissfully retired former public servant who has left the challenges of how to run the government to younger and less cynical hands, and wanders the continent in his Roadtrek Class B RV with his wife and cat. In addition to his work in the public sector, he has also at various times been a mechanic and delivery driver, skills which come in handy in his new role. Because his former job involved the forensic evaluation and sometimes the subsequent detention of some not-so-nice people, he uses the name campskunk instead of his legal name on the Internet. His was not the type of job where customer service feedback would be welcome.