Previously, I've shown you how I used a larger filter to reduce the frequency of cleaning it out to keep the Travato 59G shower drain working. That worked well, but I was trying to get rid of the small filter (why have both) and I ended up snapping the fitting right off the pump.
Rather than go without showering, I grabbed a small centrifugal pump that I was originally going to be use to recirculate the hot water to avoid wasting water prior to a shower. I didn't think it would work, since a centrifugal pump is not self-priming -- inotherwords it won't suck the water up the tube by forcibly pushing air through the pump. The pump would just spin in the air.
Funny thing is, it did work. And 3 months later it was still working. The drawback is that the water sits in the bottom of the shower basin for a while before it starts pumping out. My theory is that the water collecting in the basin will eventually seek level and get back up to the level of the pump on the inside of the kitchen cabinet. Plus, the pump blades spin at a very fast rate, creating a bit of a differential in pressure to help it along. Once the water has reached the pump, it empties out pretty quickly. I've tried switching on the pump prior to showering, and also switching it on once done, and it doesn't seem to make a lot of difference. Leaving it on means it might get started with emptying out earlier and the water level won't rise as high, but may end up with needing a second time of emptying. Switching it on once you are done adding water seems to be the best at getting all the water out the first try, although it takes a while (several minutes sometimes) for the water to reach the pump. Once the pump starts gurgling (a familiar sound when using the original pump) it's emptied out and can be turned off.
This is the "solar recirculation" pump I purchased on Amazon:
bayite BYT-7A006 DC 12V Solar Hot Water Heater Circulation Pump Low Noise 3M Discharge Head 2.1GPM
I also purchased this matching connector to allow it to be plugged in where the original pump was:
Molex -3 Match Set - (2 Circuit) w/14-20 AWG, Wire Connector - 2.13mm D, Latch Lock, MLX
That requires some soldering of course. In a pinch, you can simply pop the pins out of the connector that the pump comes with, and jam them into the molex pins -- which is what I did while I was dealing with this in the middle of a trip. Be very careful of course to observe the correct polarity. On the Winnebago connector side, the white wire is ground and the yellow is positive. On the pump, black is ground, and the red is positive. Thus red goes to yellow, black goes to white.
This is a quick video I put together showing how the pump works and how little gunk I ended up having to clean out of it after 3 months of use. Most of the gunk passed through the pump, with only some getting wrapped around the input side of the pump impellers.
I have some additional pump models I'm going to be testing out, including some that will self-prime and others that are centrifugal but don't have a bearing that is easily damaged in scenarios where hairs get wrapped around the shaft. Once I'm happy with a solution, I'll put a link here to pre-wired pumps ready to be easily self-installed.