Rhomar Glycol Results

AnOldUR

My experience with a dealer exchange back in October left the appearance of remaining Century fluid, but the dealer and nuCamp said it was not a problem. The dealer said that they did a distilled water flush before adding the new Rhomar, so there's no reason to believe otherwise.

For my own satisfaction, did a second exchange yesterday. I was going to use distilled water again, but on second thought decided it wasn't necessary. I wanted to avoid having to use extra Rhomar to push out the distilled water. With what was suppose to be a good Rhomar solution already in there, I would be doing a Rhomar to Rhomar exchange. Instead, I used a blowout method. After draining the system, I forced compressed air through the entire system at a fairly high volume.

From the results, it appears to have worked. In the top picture the left sample is fresh Rhomar and the right sample is what I pulled from the expansion tank after the dealer exchange. The bottom picture is a sample taken after my blowout method and running the system at a high temperature for several hours. It looks cloudier than the fresh sample, but I think that may be air bubbles trapped in suspension? The change in color is mainly what I was after.

db_cooper

A few weeks ago I was planning to tackle the exchange in the springtime.  But after watching Mark Turney's videos,  I've decided to stick with the Century.

I'm coming up on 2 years post finding my corrosion and cleaning it up.  I double clamped all the connections and currently see no new bulges at all.  I'm tempted to open it all up and put Miracle paint on the connectors, but I previously used JB weld on the worst areas, so I'm going to leave it be. 

For our 2015 trailer I found @ScottG procedure of disconnecting at the low point near the boiler at the check valve and blowing air  was enough to get a sufficient drain,  and was easy enough to not deter me from doing frequent changes of the Century.  

Basil48192

@db_cooper - I'm thinking the same...My 2021 has Century fluid and I have been preparing for the switch to Rhomar in the spring.  But, the more I read, the more I think I will stick with the Century.  Mainly, to avoid the chance of 'gelling', if I don't get all of the old fluid out.

bergger

Your second photo certainly looks better than the first but it still looks like it's got a little century mixed in it.  It is not as clear as what comes out of the bottle.  But a big improvement for sure.  When you used air to blow it out did you open the bleeders to force out any century trapped in the bleeders.  Not sure how the bleeders in the 320 are set up but our 2021 400 has 4 manual bleeders with 2 having a bleeder hose, 12-14" long, attached to it.  The bleeder hoses are convenient but allow more old glycol to get trapped in them.  Here is a picture of mine DIY switch from Century to Rhomar.  The picture compares Rhomar from the bottle to what is in my system after the flush and fill.  The one on the left is the rhomar in my system and the one with the sticker on it is straight from the bottle. 

 

There is no way to get every drop of Century out unless you completely take the system apart clean and dry it then reassemble it.  However if flushed very well with water prior to putting in Rhomar it is possible to get just about all of it out.  Honestly when I completed my flush and refill I could not tell the difference between the bottled Rhomar and what was in my system.  I would not do the switch because you feel you can't get enough of the Century out.  You can with a good solid water flush and proper bleeding as it is being filled with Rhomar.  Took my about 3 hours with some learning allow the way.  I could probably do it in 2 now if I had to do it again. 

manyman297

I’ll be doing a Rhomar to Rhomar flush this spring and will post pics of what I get out. 

For those who have done an exchange of the same glycol, how difficult as it? I read @ScottG great write up of the drain and homemade pump method. Sounds pretty straightforward. Just curious how it plays out in real life.

bergger

After doing the flush and switch to Rhomar I'll be changing out the Rhomar next year.  The process is exactly the same so it should be much quicker.  Maybe you've read this thread but here is a link to the page that has my experience in doing it.  It is more intimidating that actually hard to do.  If you think about it it's a simple process and compared to having a dealer do it, much less expensive too. I'm confident that next year it will take me maybe 1.5-2 hours from start to finish.  

https://tab-rv.vanillacommunity.com/discussion/13409/switching-to-new-rhomar-glycol/p5

manyman297

Thanks @bergger. My understanding is you don’t have to flush with distilled water when doing Rhomar to Rhomar. Is that correct?

bergger

Some have said to use distilled water but I know the Airstream service bulletin for the change over says to just use clean water.  I went ahead and used distilled water as our tap water has a lot of minerals in it.  I figured for a few extra dollars to just go ahead and use the distilled water.  

ScottG

manyman297 said:

...

For those who have done an exchange of the same glycol, how difficult as it? I read @ScottG great write up of the drain and homemade pump method. Sounds pretty straightforward. Just curious how it plays out in real life.

@manyman297, here's my accounting of the initial tests that culminated in that document. Other reports are scattered about in various discussions. In general, the reports have been positive and I've not heard of any major issues in using this method.

AnOldUR

bergger said:

Your second photo certainly looks better than the first but it still looks like it's got a little century mixed in it.

This got me thinking, so I took another sample. The picture that you commented on was taken right after having run the Alde for several hours. I said I thought there may be air bubbles trapped in suspension to give it the cloudier look. Another possibility is the white chalky residue that coats the plumbing (with what I believe is a protective coating) may be the cause.

The picture below is from after they system sat overnight. On the left is the new sample from my expansion tank. The right is fresh Rhomar. It did clear out and now looks more similar to your results.

manyman297

bergger said:

Some have said to use distilled water but I know the Airstream service bulletin for the change over says to just use clean water.  I went ahead and used distilled water as our tap water has a lot of minerals in it.  I figured for a few extra dollars to just go ahead and use the distilled water.  

But if it's a Rhomar to Rhomar replacement, do you still need to flush with water? I read ScottG's manual and it sounds like a Century to Century refill doesn't require a water flush. I'm assuming that's the same for Rhomar?

ScottG

@manyman297, you shouldn't need to flush with water unless you are changing the brand of glycol. When the official switch to Rohmer was made there was much ado about getting all the old century fluid out as (allegedly) the two were not compatible.

manyman297

Thanks @ScottG

Your writeup on the process is awesome. Thank you for taking the time to put this together. 

ScottG

manyman297 said:

Thanks @ScottG

Your writeup on the process is awesome. Thank you for taking the time to put this together. 

You're very welcome. If you give it a try please let us know how it turns out, or if you encounter any pitfalls.

manyman297

I will for sure. I have a 2021 400 so maybe I can lend some insight (unless somebody else here has already posted about doing this to their 400). Now I just need to find some Rhomar that's decently priced. 

ScottG

IIRC there are a few owners here who have reported doing something similar on a 400, so maybe they could chime in with some additional tips for you. @qhumberd comes to mind...

BrianZ

Looks can be deceiving, so as I mentioned previously, in addition to comparing color & appearance of the "before & after" glycol change samples, it would be more meaningful to treat these more like a urinalysis test if possible, by also measuring the specific gravity and pH, if you have a refractometer and either a pH meter or test strips.  The pH values of the two types of glycol are known & are different, though I'm not sure about the specific gravity values but it would be interesting to see and a valuable & more objective comparison.
Disclaimer:  The color, clarity, pH & specific gravity of "normal" urine can vary widely, but your glycol "before & after" change should not. 

schwartzki

When did NuCamp switch the production trailers over to Rhomar? I have a '22 400 that was produced Dec21/Jan 22 and wondering if I already have Rhomar?

manyman297

@schwartzki

You have the Rhomar glycol in yours. They changed to Rhomar at the beginning of 2021 (it might be late December 2020 builds but I'm not sure).

Century fluid is fluorescent yellow and Rhomar is Blue-ish green.

bergger

@BrianZ your method would probably be more accurate but I think I'll just stick to using Kentucky windage and eyeballing it.  I don't think the average T@b owner is going to conduct a urinalysis on their trailer.  After everything I've read and seen it appears the problem with corrosion has more to do with Glycol getting trapped in between the rubber hose and where it connects to the convector and less to do with the type of glycol in the system.  @AnOldUR that color looks pretty close so I'd call it good.  I'm sure you had a lot of air bubbles in your first comparison. 

MarkAl

@Basil48192 your 2021 may be eligible for a factory warranty Rhomar fill. We received our 320S BD in early June 2020 with the century glycol. I sent an email to the warranty dept with my trailer S/N and they replied that it was covered. I had it cleaned and filled by my dealer at no charge in Sept 2022. A replacement was needed anyways.... Awesome Nucamp! There's a thread here on this. 

Basil48192

@MarkAl - Wow!  Thank you!  I will check it out.

bergger

@Basil48192 you can also do the change over yourself and they will reimburse you.  That is what I did.  I did not trust the local dealer to do the flush and switch over so I did it myself.  I then contacted NuCamp and they sent me a check for the cost of my materials, rhomar, distilled water, 12v pump and plastic tubing. 

Basil48192

@bergger - Thank you as well!  I contacted NuCamp and they responded right away that they would cover the switch.  I'm in the same boat as you.  After reading some of these posts, I was planning on doing it myself.  It's great to know they would still cover materials.  Thanks again!