If you use air, keep the pressure below 50psi.
Then pump RV anti freeze in until it comes out ALL faucets, hot and cold. Don't forget to flush the toilet until you see pink.
Bypass the water heater, be sure to drain the water heater. The RV antifreeze reacts with the aluminum. It may cause a rotten egg smell the next time you use it.
Be sure to empty all holding tanks. Pour a small (1 quart) amount of RV antifreeze into the toilet then flush. This will keep the seal wet on the dump valve. Leave a little in the toilet above the seal.
Pour RV anti freeze in all sink traps and in the shower drain. Enough to where the excess will go into the GW tank and keep the seal on the dump valve wet.
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