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laknox
Nomad
Aug 30, 2021

Macerator pump questions

So, with my rig sitting at my sister-in-law's house, and about 80' from her sewer cleanout (basically level), I'm using a macerator pump. Not a huge fan, but it beats the h!ll out of schlepping a tote back and forth. That being said, I have a question. When pumping the black tank, the clear elbow shows completely full, with no air space. When I dump the grey tank, there's always some air space at the top of the elbow. Shouldn't the grey tank have as much venting as the black?

Second question. Not having dumped with the clear elbow and the normal hoses, I'm always surprised at how much comes out of the black tank after I dump it, switch to the grey while the black tank sprayer is running, then dump again. Question is, in y'all's experience, does the 3" hose produce a lot more "pull" to suck more out?

Lyle

13 Replies

  • way2roll wrote:
    The standard opening with a regular stinky slinky has the added benefit of physics to allow the tank to dump faster and with more force. A macerator can't leverage gravity and the weight of what's in the tank, but rather a mechanical grinder pump and it's a smaller hose. And you are pushing it 80' on level ground. So the process will be slower and with much less force. I had a built in macerator on a previous Class A and while it does have some advantages, I found that I would have to run the black tank flush a lot more.


    It's really weird. The first couple times I emptied the black tank with the pump, the water after the 2nd dump (after running the flush while the grey emptied), was pretty clear, with few solids left. The last couple times, though, as the tank was emptying, it would turn brown again, and big wads of TP (and other things) would start coming out. Same with this morning, with the flush running all the time, and I flushed 3x after the initial dump, and was still getting a fair amount of solids out. Given that DW will be spending another 5 days at here sis's place, it'll still get plenty of use until I dump again this coming Friday. I'm pretty religious about leaving a few gallons of water in the tank whenever I part it, so it makes me wonder if this is stuff that's just been stuck to the tank and is now getting washed out because it's been used so many days in a row.

    I'm still a bit confused about the grey tank not draining as fast as the black. I'm going to contact KZ about the location of the air admittance valve, since it's not under the lav sink, where most are found. Has me wondering if it's starting to go wonky and isn't breathing as it should.

    Lyle
  • Same for us what way2roll said. The macerator is convenient to have, but if the line is minimal or non existent at the dump station, we stop in there. Goes faster.
  • The standard opening with a regular stinky slinky has the added benefit of physics to allow the tank to dump faster and with more force. A macerator can't leverage gravity and the weight of what's in the tank, but rather a mechanical grinder pump and it's a smaller hose. And you are pushing it 80' on level ground. So the process will be slower and with much less force. I had a built in macerator on a previous Class A and while it does have some advantages, I found that I would have to run the black tank flush a lot more.