Any Verdict on Blue Rhomar Water Glycol and Corrosion?

manyman297

Now that we’re 4+ years into campers using the new blue Rhomar water (glycol), have we seen the same type of corrosion issues we saw with the Century fluid? So far my 2021 400 convectors seem fine. I haven’t disassembled them but keep an eye on the ones I can visually confirm aren’t bulging. 

Anybody been brave enough to go more than two years without a glycol exchange?

ScottG

I'm curious, too. Alde convector corrosion in older units with Century glycol was a sizzling hot topic a few years back that generated many hypotheses but very little hard evidence. Both nuCamp and Truma/Alde remained mum on the subject, but recommended the glycol switch in early 2021. 

The conversation seems to have fizzled since then. It's not clear if that's because the problem is solved, newer members are not as attentive to their trailers, or if it just hasn't been quite enough time for issues to surface. Additionally, if the problem is solved, it's not completely clear if that can be attributed to the new glycol, or perhaps to other changes like better convector stubs or better clamping.

I'm looking forward to hearing reports from others.  

rcarlson1957

ScottG Also think coming out with that "kit" to do the change yourself helped too. Made that process easy and cheaper. Kudos to all that put that together. Still using the old Century fluid for now and inspect all the hoses, connections and convectors at start and end of every season. Have replaced a few hoses and cleaned stubs once. If I'm at a rally and they have a real good deal on making the change I might make the switch. 

Bayliss

I exchanged the original Century fluid with the Rhomar water at nuCamp in March, 2023 (I was there to have the flooring replaced.)  That is the only exchange I have done since I purchased the trailer (12/2018) and everything has been fine with the Alde system.

pthomas745

I know that over in the FB pages, there have been at least two, one from a 2023! trailer which was discovered early this year.  The other was a 2021 400...but the info on that one was a bit sketchy.  I'm sure there are more, just owners haven't found the corrosion yet.

The corrosion on the 2022 trailer was at the check valve just next to the Auto Air Bleed Valve.  It was severe enough to have made holes in the check valve itself, causing a glycol leak. I think we have seen enough to realize the glycol makes any difference: the newer trailers have better designed hoses and convector setups, with clamps that "seem" to be properly placed.  Many owners who cleaned their convectors in the last couple of years (almost all of these from Alde 3010 trailers)  stayed with the Century brand glycol.  With proper clamping, coating of the stub ends, etc, most of the threat of corrosion will be greatly reduced.  Many of those repaired trailers will be coming up on their "2 year" cycle fairly soon, and it will be interesting to see what they find.  

Picture below of the 2023 320 with the corroded check valve.  

manyman297

@pthomas745 Crazy to see any corrosion on a 3 year old system. I wonder if this is a defect in the material and not necessarily the glycol?

I also wonder who has gone over the two year mark without exchanging their glycol? The price of the glycol alone is getting ridiculous. 

AnOldUR

pthomas745 said:

I know that over in the FB pages, there have been at least two ...

@manyman297. Between the small sample size and with no investigation into the actual cause, the question remains unanswered for now.

GregChris

2021 320s boondock. I went 3 years. I had it done at ucamp 2024. The tech said my old glycol was the new stuff, and showed no signs of breaking down yet. The system checked out fine. He unofficially thinks 3 years is appropriate. At 73 I'm probably not buying another camper, but I really like the 320 light, no Alde system. A small forced air furnace, on demand water heater and a simple air conditioner. I always thought the 320 was way over complicated for it's intended use.                    

manyman297

@GregChris Great to hear about going three years. I'm due this month for my two year change (DIY'ed it two years ago) but we've barely used the camper this year and I can't justify the cost of glycol at the moment. I know, I know. An ounce of prevention...

I did do a visual inspection of all but the two hardest convectors to check (rear bed and under dinette) and they look fine. I know there's a theory out there about clamp location but all of mine seem to be clamped further up the neck of the convectors which is supposed to allow glycol to sit between the hose and metal tubing. 

I'll probably end up doing another exchange next spring. It's getting really expensive to do this every two years even as a DIY project. 

ChrisFix

I just attended an Alde tech session with a factory rep at uCamp 25, and it is still their recommendation to change the fluid every two years. He specifically said the Rhomar is better than the Century as far as corrision resistance goes. I will note that I had a 2021 with Century fluid, which I had exchanged at 3 years with Rhomar (done at nuCamp's service center) and everything was perfectly fine in my system. 
Another note is that my current 2025 T@B400 has a ground wire run from the Alde that I didn't have with my 2021. 
Alde/Truma were doing glycol flushes at uCamp 25 for $500 (usually $650 he said).