pumps & systems
Wore out the bearings in another DC submersible pump.
Evidently,if you use it continuously a ShurFlo pump with a 2 year warranty that is rated for continuous duty isn't covered under warranty. They'll only cover it for 90 days.
Boat pumps & systems, pump problems
DC submersible pump problems
Bearings in submersibles are bad news. I've been running the 1800gph pondmaster magnetic drive with no problems whatsoever. They move some serious gallons per watt too. Time to look into air lift methods?
Walmart pumps (walmart.com)
The pumps from walmart Quiet one 3000 / 4000 pumps. They have been running fine for over a year and a half. Yes you have to use an inverter, but they only pull like 50 watts.
DC for the batteries. You can't force water through the heating system with it. You can't pump under your floor. They're basically straight up and you hope you can get to the destination by gravity.
Yoy can usually design your around an air lift- you will be able to take a system from using 300 watts on a water pump to using 15 watts on a single air pump moving the same amount of water. Boaters recommend marine water pump they last a lifetime and comes with warranty as well. Also good for hot temperature as well. In fact same with any "Professional" Tool. If you use it Professionally it is not covered with a full warranty.
Modular Heat Storage
You're trying to design a system that would use a large pump to move a lot of water quickly from a low reservoir to a high reservoir and operate for a short periods just a few times per day. So it would be using about 3x more water than a comparable recirculating system, but the added benefits would be less electricity, more "buffer" in the water, and additional thermal mass. So at it's lowest point the water would be under the floor, (like your air tubes). It would be the easiest water to force through a heater too, and it could be stored in something like this on video:
But, if you really want to be cool.... make some kind of steam powered pump that integrates into your rocketstove. Use lots of copper, cast iron, and cool looking gauges from the 1930s. If you do this, all of your wildest dreams will come true!
The problem with the majority of the pumps is that the specs say they are rated for continuous duty. They define that is continuous for a few hours at a time. Sump, bilge, and even livewell pumps are all designed this way. Basically, they have nylon sleeves (seals) that are used to keep the water from leaking into the motor. They eventually wear out and the water will eventually leak into the motor. Get a submersible mag-drive. The motors are completely sealed from the impeller and have good bearings in them. The magnetic coupling between the motor and the impeller is the way to go.