Anti-freeze Frozen

[mdebs]

I stopped my to check on my motorhome yesterday and noticed that the RV anti-freeze in the toilet bowls was frozen. Low temperatures have been in the low teens recently here in the Detroit area. I am wondering why this would happen and how much trouble I am going to find when I dewinterize.

[HangDiver]

Originally Posted by mdebs

I stopped my to check on my motorhome yesterday and noticed that the RV anti-freeze in the toilet bowls was frozen. Low temperatures have been in the low teens recently here in the Detroit area. I am wondering why this would happen and how much trouble I am going to find when I dewinterize.

Is it truly frozen hard or thick like slush? Thick like slush is normal.

[OYO]

Originally Posted by HangDiver

Is it truly frozen hard or thick like slush? Thick like slush is normal.

Correct.

[5picker]

First... is it pure R/V antifreeze or is it possibly diluted with water from not first blowing out the lines?

Second... while R/V antifreeze will get slushy and possibly even freeze at below zero temperatures, (most are good for -25ºF to -50ºF, some even more), but UNLIKE water, it will not expand when frozen.

If your is diluted, all bets are off.

[mdebs]

It is frozen, not just slush. Although, I did not blow the lines out first I used quite a bit of antifreeze to run through the lines.

[mdebs]

So if the anti-freeze doesn't expand, does that mean it should not damage the lines?

[5picker]

What brand?
R/V antifreeze for sure?
Do you have any left?

If it is freezing SOLID at temperatures 'in the teens', something is wrong with it or it is diluted.

[5picker]

Originally Posted by mdebs

So if the anti-freeze doesn't expand, does that mean it should not damage the lines?

R/V antifreeze does not expand when frozen.

Water is the only common liquid that expands when frozen.

[mdebs]

I believe it was Winter Tech RV Anti-freeze. I don't have any left. Are you supposed to blow out the lines and then run anti-freeze through them. From every thing I read, it was one or the other.

[jeff64]

Originally Posted by mdebs

I believe it was Winter Tech RV Anti-freeze. I don't have any left. Are you supposed to blow out the lines and then run anti-freeze through them. From every thing I read, it was one or the other.

At least open up the low point drains, open all faucets including outside shower, pull the anode on the WH and step on the toilet pedal until its done running out. Isolate( turn the valves) the WH from the rest, even if you don't blow out with air. The RV antifreeze is close to 50% water to start out with. A few ounces of water left in the corners of the system won't matter mixed in 2+ gal. of AF

[5picker]

"Supposed to" is subjective.

If you don't blow out the lines first, (or at least drain) you run the risk of the antifreeze diluting with the water in the plumbing and not giving optimum protection unless you run the lines open for a good amount of time. This method also allows for much less antifreeze needed to complete the job. (usually 2 gallons or maybe less depending on rig size)

[Flybob]

If you have not diluted the antifreeze with a lot of water remaining in the lines, you will be OK. The key property here is not if it freezes or not freezes, but rather expansion. It must expand to damage the lines, RV antifreeze is designed to not expand above about -50F unless it is diluted. A quick search will show we have this discussion every winter.

[5picker]

Most antifreeze will at some temperature freeze solid. Even ethylene glycol. (automotive antifreeze and NOT to be confused with propylene glycol)

Burst protection is what is most important and it doesn't matter if it turns to slush (or freezes solid) as long as it doesn't expand.

Here is what the DOW Chemical company says of it's brand... "When most fluids freeze they expand in volume, which can cause pipes or other containment vessels to rupture. When a water-glycol mixture freezes, it retains its flow-ability and does not create added pressure in pipes or vessels. This makes it an ideal solution for burst protection in pipe and containment systems."

Again, most R/V antifreeze is good to -25ºF to -50ºF and doesn't begin to slush up until well below 0ºF. If yours is frozen SOLID at "in the teens"... something is amiss.

[Cypressloser]

Do a "smell test". Plumbing antifreeze smells funny, and unless someone sold you water with food coloring you have nothing to worry about.

[WFD]

Where we live, it gets to the -30's range several nights over the course of the winter and sometimes for several days on end. The Rv antifreeze I use is pretty regular stuff, good to -50, and I have never had it freeze solid. It does turn to slush in the minus teens but always stays in a slush state....I blow my lines out prior to running antifreeze through the system.