Re: How do RV pumps work?

On 11/15/2024 9:25 PM, Charlie wrote:

On this Sun, 3 Nov 2024 21:52:01 -0700, Charlie wrote:
 

How do RV pumps work?
>
A friend with an RV bought a pump and got an extra by mistake which Amazon
told him to keep so he gave it to me because he knew I always wanted to
build a solar hottub. <https://www.amazon.com/dp/B0DF7B1VYD>
   "12V RV Water Pump Kit 20PCS, 4.0 GPM Camper Water Pressure Pump
    with Pressure Switch, 45PSI Self Priming Diaphragm Pump with     Alligator Clips for Camper Yacht Marine Caravan Kitchen Bathroom"
>
I don't understand what the pump is for as I don't own an RV nor a Camper,
nor a Yacht or even a Caravan - but I do have a spa which I'd like to heat
with solar power in the summer months.
>
I connected that pump to an old car battery and it pumped water out of the
spa back into the spa via it's input and output garden hose connections.
>
If I buy a few hundred feet of black hose, I can probably loop it on the
ground next to the pool in the summer months to soak up the sun's heat.
>
But when I connected the input to a garden hose, nothing came out. The pump didn't even turn on.
>
Given I'm not using the pump the way it's supposed to be used, I'm just
wondering what it supposed to happen when you hook a garden hose to it.
>
The description says it's supposed to pressurize that water.
>
But it doesn't do anything and yet when I disconnect the garden hose, it
works find in the manner I described above with one end in the spa.
>
How are these things supposed to work in an RV?

 I got one and tested it, and found out how they're supposed to work.
 You hook one end into a tank of cold water (like a spa or RV water tank).
Then you hook the other end into a faucet (which can be a garden hose).
You power it up.
If the outgoing garden hose is closed, nothing happens.
But if you OPEN the valve on the outgoing garden hose, then water starts
pumping (by magic I guess) by the pump from the spa or water tank.
 If you CLOSE the valve on the outgoing garden hose, then the pump (again by
magic) senses that the output stopped so it shuts off the pressure pump.
 The pumps don't even have on/off switches which is why it confused me.
They go on and off depending on if water is flowing out or not.
 Don't ask me how they know that water is flowing though.

I'd explain it but you probably wouldn't understand .
--
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