OK. ShawnR, I sanitize in the spring when I dewinterize. I pour a couple cap fulls of plain old Clorox in the end of the hose and hook it up and fill the fresh water tank just enough the fill the entire plumbing system which includes the hot water heater. Then, make sure all faucets and low point drains are closed. Turn on water pump. May take a few minutes because, you are filling the hot water heater tank, also. Go thru and open all faucets, hot and cold, until all air is gone and getting a steady flow. Simple.
To winterize, I go thru and open everything. Remove plug from hot water heater tank, open pressure relief valve at top of tank, all faucets and low point drains and fresh water tank drain. While everything is draining, I use a large empty coffee can to set under the whole house filter to remove canister and filter. Empty filter canister and screw it back into place.
Once all draining and piddling has stopped, I put the plug back into the hot water heater tank and go thru unit to close all faucets and low point drains.
Using my portable 3 gallon air compressor and an adaptor I made, I turn on compressor and allow to fill and shut down. At that point, I set the regulator to about 40 psi and hook up to the city connection. Compressor usually starts again, to pressurize the entire plumbing system and shut down. Then , I go thru and open all faucets one at a time on both hot and cold until only air is coming out. I also, open foot flush on the toilets until air comes out. Once that is done throughout, I do run the water pump for a few seconds to empty it. Now, I go out and open all low point drains one at a time until air is coming out. Done!
The air compressor has just done a lot of running, obviously. So, unplug it and put away.
I go back to the unit, open pressure relief back up on the hot water heater tank and remove plug and, reopen all low point drains.
Now, go in with a gallon of antifreeze, open all faucets again, and pour antifreeze down the drains for all sinks and shower. At this point, I have very little antifreeze left so, I pour what is left into toilets to keep seals from drying out.
I leave everything open thru the winter. If, by chance there is any water in the system and it freezes, it most likely will not damage anything because, it is not under any pressure and has room to expand when it does freeze.
Sorry this so long but, this is what do. It is my story and I'm sticking to it!