I had a compressor with hand crafted adapter to water system. I used to run a small setup in my last place in the boathouse to have pressurized water down near the water. Much simpler setup though.
You were right to use the compressor. I had depressurized pump and taken the foot valve off first and started down at that end first. Then I shut the house off at the pump to keep it "closed".
I had the compressor basically on a spigot (hot and cold) at the house. Then I opened hot water heater drain first. It was the compressor driving that water out. And it had to go up from the base of the the water heater. Once hot water was empty. I did the first faucet, then closed the hot water drain. Then opened up the next and closed the previous. Regulator is not good on the compressor and had to be careful not to get to much pressure in the system.
Then I wanted to push water out around the pump but it was going straight out the foot valve. So I had to put that back. and took it out later.
I did put RV antifreeze in the pump and let it spin a second. Not sure that did much.
I also put plumbers grease on all the plug holes on the pump. They tend to get rusty.
I put 1 gallon down each sink, tub etc.
I put 2 gallons in the water closet and flushed it (with it mostly empty in the bowl). It was just enough to "flush".
I have a 5 gallon bucket in the tub of water and put 1 gallon of RV antifreeze to maybe not freeze. Also 5 spare gallons of RV antifreeze. In case I visit over winter and need a couple flushes.
We managed to stay until Dec 6., that's like 2 weeks before winter solstice. Had some gorgeous weather at times. Got tons of projects done. Expecting a $500.00 electric bill though. Which is fine.
Even though it was cold, dark and windy when we left, we still miss it.
I have 5 Blink cameras. 2 outside. 1 in garage and 2 inside. Plus 10x Zoom PTZ AXIS Web Camera. Weather Station. Two Multi Sensors (Temp, Motion, Vibration, Pressure humidity). One in the house and one in the pump house. Curious how cold it will get. ZWave Smoke alarm . Sense Power Monitor. ZWave motion switch in Garage to control a 150,000 lumens light
. ZWave light switch for floods. 4 Wave light bulbs. ZWave Door Lock. All Zwave can be controlled monitors through SmartThings. Best Thermostat (using a cool high voltage to low voltage adapter).
Oh shoot, just realized I left the "cottage sitter" running which will call us every time it goes below 40F in the house. Need to remember how to program it remotely. Ugh.