Blow Lines or AntiFreeze, or both?

1. Water left in line? Possibly if you have a low spot in the line. Will it burst a line? Possibly, as water freezes from the top and then their isn't enough room for ice to expand.
2. Bursting a line with air compressor. Pretty had to do unless you use one from a tire shop. Ones you use at home don't usually have enough pressure to burst a line. You can use a water reducer if you are concerned.
3. Is there a need to do both? I do just because I don't want a burst line that is impossible to get to.
4. Don't know about washing machine.
5. Just blow the lines? You can catch the anti freeze as it comes out of the faucets and save some that way. There is an active post regarding this.

I blow the lines and add anti freeze. I don't know how you would get all of the water out of the water pump and associated plumbing by just blowing the lines.
I can't help you with the washing machine but I'm wondering about our residential fridge. It has water and ice maker that I will have to take care of. If you set your compressor pressure to around 40 PSI you don't have to worry about bursting a line.

Can't help with your last 2 items since I have neither a washing machine nor use our 5'r in the winter....... yet.

However, when winterizing, I do both. I set the air compressor to 40 psi and blow out the lines, then pump in antifreeze. Never had a problem! I'd rather be safe than sorry.

I drain the water tank and the water heater, then I set the pressure regulator on the compressor at 55-60 PSI (the same pressure that the onboard water pump puts out).
I blow all the lines, at least twice, then pour some RV anti-freeze into the drain traps and toilet bowl.
I always have to remind myself to NOT forget the black tank flush, the spray nozzle at the toilet, and the hand washer spray nozzle.
Then I remove the water pump intake strainer, empty and clean it, and run the pump until no water comes out.
I have never had a problem with any lines or fittings freezing and breaking.

empty_nest wrote:
Can't help with your last 2 items since I have neither a washing machine nor use our 5'r in the winter....... yet.

However, when winterizing, I do both. I set the air compressor to 40 psi and blow out the lines, then pump in antifreeze. Never had a problem! I'd rather be safe than sorry.

I do the same. If I head south during cold weather, I wait till we're out of freezing temps before using water system and winterize again before getting back north.

I blow out lines only and do not add antifreeze. Drain holding tanks, and low point drains and do not add antifreeze. I only use antifreeze in the P traps. I live in a northern climate and have never had any issues...

I do both. I also made up my own regulator setup from Harbor Freight so that I only put in about 50psi MAX into the system. No issues yet doing both.

If done correctly either way works well.

Blowing out the lines just seems to be easier and quicker for me. I can blow out the lines and winterize in about 15 to 20 minutes. Could do it much quicker before I had a W/D. I have a portable commpressor and I can winterize and de-winterize on the road.

The advantage of blowing out the lines is you don't have that yucky stuff in your water lines. Every spring check out the posts about water still tastes funny after flushing RVantifreeze out.

I use a regulator on my compressor To keep pressure below 45 pounds. Plus I always have one water valve open all the time during the process. Open 2nd valve then close the 1st valve.

W/D: I disconnect the water lines from the washer and blow out those valves/lines the same way. I pour about 1/2 gallon of antifreeze in my Washer and turn it on and spin it out. That antifreeze will fill the washer drain trap

I pour antifreeze in all the drains. Make sure it is enough so some goes down into the grey tank and keeps the grey dump valve moist.

Don't forget to open toilet flush valve so that also gets blown out & also outside shower valve if you have one. I also add some antifreeze to black tank to keep black tank dump valve moist. Then add some to toilet bowl. BTW if you have any water filters remove the housing water will collect in the bottom of the filter housing.

Works for me. We get chilly in NW WY and no problem with blowing out lines. Down to 20F this morning. We will get down to 25 to 30 below in the winter.

With your big Montana you have more lines running everywhere I guess...
I drain my fresh water tank first and open the hot water spigot when I do this to hopefully drain it down at the same time. Then I hookup my tankless 12VDC air compressor to the city water inlet and then go open each sink spigot to let out water until it starts blowing air.

Once I do that to all my lines then I add a small amount of antifreeze to the p-traps.

Of course where we are at only has a couple of freeze days a year that doesn't last long- warms up the next day...

Using the blow-out is perfect for us doing our off-road camping. Can blow all the water out in five minutes time then refill the next day when it warms up...

Moving the big house around the country like you guys do i would probably have to change what I normally do...

No problems with my method yet...

Roy Ken

If you blow the lines why would you need anti freeze in the lines????? The air in the lines wont freeze.:h