drain question/ winterize question

[lynn boyd]

im sure this has been answered on here at one point but couldnt find anything about it in the search.
my 2006 coachman has 3 water drains. one for fresh water and 2 tubes next to each other under the very back of the trailer. these 2 seem to have a little pressure behind them. im guessing one is the "low point" drain.
my question is.. My friend says to winterize his rv he just pulls the low point drain and drains the water heater and has never had trouble. I pulled all 3 caps, drained all the water and water heater. bypassed the water heater and hooked a line from the water pump to antifreeze jug and pumped all the lines full.. (i could see antifreeze in these 2 drain tubes in the back as well)
this method worked good for me.. other than it takes awhile to get all the antifreeze back out of the system!
does anyone else just pull the low-point drain and call it good? and what is that other drain tube next to the low-point drain??

thanks in advance!

[OneRVer]

On my 2000 Coachman I had a fresh water tank drain and a low point drain.

[br9]

On our tt the dealer said they were both low point drains. One hot one cold. On ours one is blue one is red so I believe him.

[WindsorDave]

Our rig has low-point drains for the hot and the cold piping. There is a third valve nearby that is the fresh water tank drain.

After dumping black and grey water tanks, I open the low-point drains, prop open the hot water heater pressure relief valve, and open the fresh water drain. After they all quit dripping, I screw in one of those schrader valve-to-hose-bib adapters at the main water inlet. They are available at any camping supply store.

Then feed compressed air into the system being careful to not apply more than 60PSI. More water will come out of the low-point drains. When that stops, they are closed. Then I crack the hose bib connection to the electric valve for the ice maker and apply the compressed air again until only air is coming out of that joint, then re-tighten.

At that point I apply compressed air again while DW goes around and opens each water valve in the coach, one at a time. Sinks, shower, flush the toilet, washer/dryer, etc., leaving each valve open until only air is coming out.

Then I pour antifreeze in each drain (sinks, shower, washer/dryer, toilet) to displace any residual water in the p-traps. Enough antifreeze combines with the p-trap water to prevent its freezing in the holding tanks.

All this sounds fussier than it really is and the real benefit is when you want to de-winterize, just hook up the fresh water hose to put water in your tank and go. Don't forget to make sure that the ice maker hose connection is tight and that the hot water heater fills up with water before you turn it on.

FWIW