I will say good advice is when I first initiated the relief valve on the water heater before unplugging the drain to the water heater and even with doing that first the plug shot across yard for 2 feet. Do not stand in front of it was something I did right! I am pleased to know that the water pump would work off the house battery and given my doubts that I did everything right I am thinking of filling the fresh water tank with more anti-freeze and making sure everything got covered.micabarry wrote:The water pump runs off 12v so you can run it off your house battery and you definately want to protect the pump by pumping antifreeze from the fresh water tank. I ve by passed the hot water heater now but before that I drained all the water the way described above, including taking plug off hot water tank, screwed a little plastic valve (Wal-Mart has them) on the hose input and used a compressor to blow out lines. Then I bought 7 gallons of antifreeze, dumped it into the fresh water tank using a plastic quart soda bottle with the bottom cut out as a funnel, turned on the pump and pumped until water came out all the faucets, flushed the toilet and sprayed the shower hose. Then I would drain it all into buckets placed under the vehicle to catch the anti freeze. Most will come out the hot water heater. I refill the empty jugs and end up with about 5 gallons for the following year. I live in Vermont so I need to plan on 20 below. Never had any problems doing this and I use the same procedure with the hot water bypass but obviously don't use as much antifreeze.
One other important preventive maintenance thing you can do during this process is to take the opportunity to wet vac the hot water heater. I have adapted a piece of tubing by running a bent coat hanger through a plastic pipe so I can snake it into the hot water tank through the drain plug and vacuum out all the sediment that settles in the bottom of the tank. I'm amazed at what comes out.
I am going to wet vac the hot water tank bottom too.