Older RV anti-freeze ok?

[jw21id]

Hello everyone -



Just got back into having a travel trailer and purchased a used Airstream last week. With winterizing approaching, I have 3 gallons of RV antifreeze probably about 5 years old, unopened & left over when we had our last trailer.


Is product this old still effective enough to use?

[bweybright]

I personally would expect it to be fine and would use it. But if you want to be sure Camco has a pretty good explanation about the various RV options on their website. As well they have a technical QA section that could back up or prove my assumption wrong option.
An interesting question as I always assumed there was no shelf life on it but do not really know.

[Trnpk Crsr]

Test some of it and see. Put some in a plastic cup and then put it in the freezer. Then see what happens.

Cheers,

John

[bweybright]

A good idea to freeze and test. As long as you read the Camco info and understand what you are testing. Some slushes up but does not freeze to damage the lines, some does not freeze (if I remember what I read correctly). So just putting a cup in a freezer does not help you unless you know what you are testing and how it is meant to function. That being said from my experience propylene glycol is the preferred as it does leave a taste in the fresh water lines.
Correct me crowd as needed, I could use a refresher this time of year.

[JCWDCW]

Chemical Engineer here!
The components in RV antifreeze are perfectly stable and I would use it without reservation.
The older AF had a propylene glycol type base. New products have ethanol. Older base left a lingering taste that we are all familiar with. The ethanol base seems to rinse out more readily
JCW

[greghoro]

If the seal is still intact and the level of the liquid in the bottle appears to be full, should be no problem. Anything with a broken seal should be reserved for waste side winterizing only.

Note, there are two formulas for RV antifreeze. The first, which is typically cheaper and easier to find is primarily ethanol based and can easily be identified by a flammable warning on the label. The second formula is propylene glycol based and is not flammable.

The ethanol based formula tends to evaporate when used in an open system with access to the atmosphere, such as p-trap and toilet bowl. Some have also said that the ethanol based formula also leaves a more lasting aftertaste when used in fresh water system, requiring a longer flush time when de-winterizing. [Edit - and I am directly contradicting the previous poster on the aftertaste, so I defer]

It is generally discouraged to pour the antifreeze into the fresh water tank to facilitate the use of the RV pump to circulate the antifreeze. Flushing the tank to remove what the pump can’t reach can take an inordinate amount of water to eliminate all of the latent antifreeze.


Greg

[ROBERT CROSS]

We ONLY use the RV AF in the P traps, toilet, sink & sprayer shower head. All lines get blown out. Low point drains & all faucets left open. No AF in the tanks. Toilet bowl, seal lubed and closed.
Gave up pumping AF thru the lines 6 yrs ago after 11 Seasons of PITA Winterization's SFSG

POI...i'm still using a case I bought on a Spring Sale 3yrs ago.

Bob
🇺🇸

[jw21id]

Thanks for the feedback, everyone!

[ROBERTSUNRUS]

Hi, I read somewhere that RV antifreeze does freeze, but it doesn't expand. Being from Southern California, I never winterized my trailer. After moving to Oregon I had to. Only twice did I pump RV antifreeze through my system. I now drain everything, blow out the lines, and only put RV antifreeze in the traps. Much like my friend Robert Cross.

[OTRA15]

Echoing the Bobs.

Blow out all lines.

Drain H/C low points, pump, pump filter, supply hose to pump, water tank, and water heater.

AF only in traps.

KISS

[eubank]

Pour some in a small plastic container and put it in your freezer overnight. It may freeze, as RV antifreeze will do, but it should NOT expand. That's critical.


Lynn