Don't Understand Value Of 3-Valve Hot Water Bypass

I've blown out the lines and still have had water in low spots, so that is why I bypass the water heater. Instead of RV antifreeze, I pour cheap vodka in, run that through the lines, then blow all that out with the air compressor. The alcohol inhibits mold growth, and any water that is in low parts will have enough booze in it so it doesn't freeze at 32 degrees.

It is just a matter of choice on winterizing. Here in Northern Neck Virginia it really doesn't do the long cold snaps so I can really put the draining water at the their low points to good use for use. Then I can do the BLOW-OUT method by pump air into the city water port. After the water has drained out then I just add a little bit of pink antifreeze to the P-TRAPS...

We do a lot of short trip camping off the power grid and sometimes find ourselves facing a very cold night up in the mountain off-road sites here on the East side. Doing the blow-out of the lines is great for us during these short trip camping times. My portable air compressor connects up at the city water port and does it thing real quick. Then all I have to do is drain the fresh water at the low point valves...

For us using the blow-out method is real quick and can be done usually in five minutes or so...

I too never use the three winterizing values much as well ... Great to have some choice's to do your things your way...

I double think I would be much a fan having the pink stuff in the water lines. Have never tasted the pink stuff but doubt if I would like it...

Roy Ken

I've got a three valve system. No bypass valves to go bad, which they do.
I can do the whole winterize thing in less than 5 minutes using less then 1 gallon of antifreeze.
I don't worry about if I got all the water out and don't mess with the low point drains or if they really work.

It is just a matter of choice on winterizing. Here in Northern Neck Virginia it really doesn't do the long cold snaps so I can really put the draining water at the their low points to good use for use. After the water has drained out then I just add a little bit of pink antifreeze to the P-TRAPS...

We do a lot of short trip camping off the power grid and sometimes find ourselves facing a very cold night up in the mountain off-road sites here on the East side. Doing the blow-out of the lines is great for us during these short trip camping times. My portable air compressor connects up at the city water port and does it thing real quick. Then all I have to do is drain the fresh water at the low point valves...

For us using the blow-out method is real quick and can be done usually in five minutes or so...

I too never use three winterizing values much ... Great to have some choice's to do your things your way... Have never tasted the pink stuff but doubt if I would like it...

Roy Ken

Okay, I get it about the 6 gallons of anti-freeze. But why run anti-freeze through the lines in the first place? Why not blow out the lines and have no liquid at all except in the bottom of the fresh water tank and drain traps? Add anti-freeze only there, and run a bit through the on-board pump and you're done....right? Isn't every rig equipped with low-point drains for both hot & cold lines to achieve complete draining?

Adding: Oh, I just read more replies that beat me here. I see you pre-answered my question about blowing out lines.

There are 1 valve systems (with backflow preventers), 2 valve systems, and 3 valve systems.

All keep the antifreeze out of the water heater. That is the only reason they exist. If you blow out the lines, you don't need a bypass.

I don't like the 1 valve system because the backflow preventer can fail. Mine has. I have a bypass valve to put in instead, but haven't had the motivation to work in the small space behind the water heater yet.

I like the 2 valve system best. The two valves being bypass valves, one on the hot water line, and one on the cold water line.

I don't see the need for the third valve in the 3 valve system. Instead of 3 shutoff valves with 2 T fittings, 2 bypass valves do the same thing.

If your using antifreeze when winterizing. Then the bypass valve allows total bypass of water heater after it has been drained. This saves up to 6 gallons of antifreeze on a RV with a 6 gallon water heater.

The system allows you to winterize using anti-freeze without filling the water tank with 6 or 10 gallons of anti-freeze.

By pass the water heater and anti-freeze only goes through the lines, faucets, etc...not into the water heater.