Switching to New Rhomar Glycol

System

This discussion was created from comments split from: Changing out the Alde fluid..


MOD NOTE: I'm kicking this important topic out to its own thread. The "Changing out the Alde fluid" discussion is already bloated, and I'd like to keep it focused on creative DIY options for how to actually change the fluid.

N7SHG_Ham

What I find interesting is Airstream is doing the flush and fill with new formulation glycol as a recall. It seems to be a big deal. All AS dealers should have the means to do this, they were supposed to be sent the pump, etc. I have a dialogue open with closest dealer to me and they have confirmed they have everything to do this, I am only waiting on a price (since AS owners are free they weren't sure what to charge a cash customer).

A little disappointed to see NuCamp just say there is a new fluid and not be doing a recall, although from a cost standpoint I do understand why they are mum. I would guess several thousand units out there that now need new fluid. That would be an expensive hit to the bottom line, much more than a limited floor replacement. I think when it comes to big oops like the Alde fluid, or replacing the Air8, etc., a little manufacturer like NuCamp just doesn't have the cash to do it.

Denny16

True about nüCamp’s limited resources.  However, they could provide the new glycol to dealers for an initial change over for free, so the TaB owner only pays a fixed labor cost, TBD by nüCamp, not the individual dealers.  This would make the upgrade a little more equatable.  Perhaps nüCamp could supplement the labor cost, to bring is down a bit, especially for TaB’s built since 2018. 
cheers

fstop32

I think anything manufactured in 2015 should get a free change of fluid and all new convectors and hoses!

ScottG

If owners do decide to switch to the new glycol, here are a couple considerations.

Flush really thoroughly. I flushed my system before refilling, and since I had it apart apart anyway (because of the corrosion issue) I decided to flush the heating loop and boiler separately. I run about four gallons of distilled water through the circulator pump and boiler, and was still getting a bit of green in the rinse. (I eventually called it good because I was out of distilled water.)

In another discussion, @MadCityJack noted his dealer ran around fifteen gallons through the system to flush it. I don't think that was overkill.

Also in that discussion, @Sharon_is_SAM raised the question of whether residual crystals of the old Century glycol remaining under the hoses would be a problem. I have no idea, but belt-and-suspenders types may want to consider pulling apart every hose fitting (bulging or not) to inspect and--if necessary--clean up any deposits on the aluminum or stuck inside the hose.

Under the circumstances, I think switching to the Rohmer fluid is probably best practice, but since I already had four gallons of Century on hand (at $25/gallon) I decided to use that first.

Denny16

We had our glycol flushed and replaced just before the Rohmer announcement came out.  So we will wait until next time around to do ours also, unless nüCamp comes out with some more guidance and a special deal.
cheers

N7SHG_Ham

Ran across this today on an Airstream forum. The AS service bulletin which I have also located also adds grounding to the Alde boiler unit. I think there is some sort of galvanic process going on and thus why the big recall by Airstream. Hundreds of dollars of parts and labor per unit times hundreds of not 1000's of Airstream units seems like a big hit if it wasn't needed.

pak

N7SHG_Ham said:

Ran across this today on an Airstream forum. The AS service bulletin which I have also located also adds grounding to the Alde boiler unit. I think there is some sort of galvanic process going on and thus why the big recall by Airstream. Hundreds of dollars of parts and labor per unit times hundreds of not 1000's of Airstream units seems like a big hit if it wasn't needed.

Thank you for posting. Hopefully we will get some direction for our units.

fstop32

Yes, @N7SHG_Ham, thank you for the legwork researching this issue, this is becoming very interesting...

DelZMan

https://static.nhtsa.gov/odi/tsbs/2020/MC-10170838-0001.pdf

N7SHG_Ham

@DelZMan yes that is official AS recall bulletin. I find it interesting it is listed at NHTSA.

N7SHG_Ham

My nephew works at a HVAC place and he says nothing special he can see about new recommended fluid, in fact he says they sell another brand that is good. Any food grade inhibited glycol should work. He says important thing is no dilution with tap water use only deionized water. I have asked if distilled works too?

He will be getting me a price tomorrow on the concentrate they sell.

One of two AS dealers in Oregon has quoted roughly $400 for new fluid and $400 or so for labor, so a switch is starting to knock hard ona big bill.

The other AS dealer said no go at thier shop on anything but AS units and suggested I contact NuCamp for ideas. I think it is generally recognized that very few NuCamp dealers have equipment or knowledge to do the swap unfortunately.

If I can source the new fluid, then I think some sort of redneck-red-green pump-duct tape setup and a DIY project may be way to go. Alde UK prices for the pump seem to be around $900 USD. I am not even sure they sell to general public here in USA.

A real condrum Alde and NuCamp have going here.

pthomas745

This is looking more and more like a real bucket of worms for Alde/NuCamp/Airstream, etc.

Denny16

The only Airstream with the Alde is the Classic, which starts at $162,000!  I do not think they sell as many of these trailers as they do the other models, perhaps a around a 100 units or less per year. Their most popular seller is the BaseCamp, followed by Bambi and Caravel, these are $64,000 to $40,000 trailers.  So the Airstream recall is more of a full service and inspection of a very expensive trailer, which is a very small part of their overall production.  The rest of the Airstream trailers have forced air furnaces and tankless LP water heaters, not the Alde.  

So getting the Alde with a $30K-40K trailer is a bargain.  Also, the Alde/Truma notice does not state pervious sold units need to be converted to the new fluid, just new units as of Jan 2021 are being specified to use the new fluid.  I think we need to be careful of implying that every trailer with an Alde needs to be changed over ASAP.  We plan to make the change at our next glycol fluid change, which makes more sense, and is a $300-400 dealer and job, including glycol and labor.
cheers

Bayliss

I find it interesting that Air Stream sent out their letter offering the free system flush and glycol to their customers in January 2020, yet we are just now learning about the situation.  I think Alde needs to address this issue for T@B owners as well, and it would be advisable for nuCamp to be proactive in working with Alde to address the situation soon.

N7SHG_Ham

@Bayliss I agree. NuCamp did acknowledge a new fluid, but no mention of a recall. I honestly think way more to story than Alde just changing suppliers.

Denny16

Bayliss, the change from Truma/Alde is a manufacturer’s notice of a change in their product, not a recall as the result of an issue with the previous glycol.  Here is the notice Alde sent to nüCamp:

“SUBJECT: GLYCOL CHANGEPleasant Valley Teardrop Trailers/nuCamp has been notified by Truma/Alde that they will be switching to a different brand of glycol (Rhomar Water RG-RTU-50).  This change is a requirement from Truma/Alde for new units to be eligible for warranty.   Due to this requirement,all nuCamp production units manufactured on or after 1/4/2021 will contain the Rhomar water glycol.”

They also noted you can not mix the the new Rhomar glycol with the glycol previously used.  A tech notice was sent to Airstream for the procedure to change out previously manufactured aA.de units to use the new fluid.  Airstream decided to provide this service to their customers who purchased their top end Airstream Classic trailer (a $164,000 unit), and is the only Airstream that has the Alde unit.

Cheers

Bayliss

@Denny16, I am aware that there is not a formal recall and I have previously read (and saved) the notice you repeated above.

Regardless, a logical conclusion is that there is more to the story if they are going back to 2018, 2019 and early 2020 models.  If it is truly just a new and improved product that provides better performance, then there is no need to go back to 2018.  Also, Truma/Alde has made the Rhomar product a requirement for warranty coverage on 2021 or later trailers, so that is a strong indication that they are aware of some issue with using the previous glycol (which most T@B owners currently have in their Alde systems.)

Beyond good customer service (i.e., pleasing their high-paying customers of the only line of trailers they sell with the Alde), Airstream may have simply conducted a cost-benefit analysis, weighing the cost of a flush and fill vs replacing corroded parts down the road.  nuCamp and Truma/Alde may be well advised to conduct a similar analysis, particularly if the representation of this simply being a new product is not the whole story.

I love my T@B, and have experienced no known issues with my Alde.  But, if I encounter issues with it in the future (e.g., corrosion), despite properly maintaining the system, I may very well be on solid ground in having all or part of my Alde system replaced at no cost to me.  This is just my personal viewpoint, based on objective facts.  

Tabaz

Has anyone done a side-by-side chemical analysis of the Century and Rohmer fluids?  This may provide an indication for the switch.

ScottG

@Tabaz, I've looked at the SDSs (Safety Data Sheets). The main ingredient for both is propylene glycol, but the rest of the secret sauce is"proprietory."  

Sharon_is_SAM

@Tabaz - part of the issue with trying to do that is each manufacturer has a secret, magic formula that they don’t always release.  Alde should be able to tell us exactly why Rhomar is better than Century, rather than just saying it’s a “better formulation”.  

Tampakayaker

Like when Coke decided on the New Coke debacle

N7SHG_Ham

It would be good to know why Alde picked Rhomar as the cure to some issues with Century.

When you start looking around there are tons of similar fluids.

As mentioned above my nephew works at a HVAC supply company and they sell a different product that has worked well across many installations. This type of fluid is used a lot apparently for not only heating, but chilling in industrial situations. It isn't recommended to mix any brands, however, once flushed, wonder if it really matters if Rhomar, Century or something else is used?

https://www.amazon.com/dp/B008HQ79A8/ref=cm_sw_r_fm_api_glt_fabc_SPQ6DCH57NMWGWQ65M51

N7SHG_Ham

I contacted Alde and asked a few things, and am sharing why the switch in brands.

"The switch was made because the Alde system uses aluminum piping and convectors.  The Rhomar glycol is specifically formulated with corrosion inhibitors for an aluminum heating system."

Does that mean the Century fluid did NOT have inhibitors for aluminum or enough? Unanswered, but implied.

Alde still recommends two year service after the switch, hmm.

I think the safe thing for ALL Alde's is a switch ASAP and regular changes. That still may not guarantee a trouble free experience, but my take is it won't hurt. The Airstream recall would imply they think so too.

I have asked Alde a couple follow up questions and will report anything of significance in this thread.

ScottG

Good info, @N7SHG_Ham. Interesting that they mention "piping and convectors" but not the boiler core specifically.

This is the first clue suggesting (but only suggesting) that the mysterious problems Alde may be "investigating" are the same as those some of us are encountering here.

The big question for me is whether those boiler cores are also being affected. Replacing convectors is a relatively simple and inexpensive task compared to replacing the boiler core or--if that is not an option--the entire Alde.

N7SHG_Ham

@ScottG isn't the boiler core stainless? I thought someone verified that?

I have been looking up a lot of heat transfer fluids and there is a ton. Some differences may be the glycol used, Dow for instance makes a lot of noise about that, but almost all are glycol at 96% and 4% an inhibitor. The premixed versions add deionized water to dilute. The ONLY difference between any of these I think is purity of glycol used and the secret sauce in that 4% additive package.

There may be more than one inhibitor, but this excerpt seems to be a common one:

The inhibitor used in glycol/water systems is Dipotassium Phosphate. The Phosphate based inhibitor is effective in preventing corrosion of metal commonly used in HVAC, food processing and process heat transfer equipment. These inhibitors prevent corrosion of metals in two ways:

First they passivate the surface of the metal, reacting to the surface to prevent acids formed as a result of glycol oxidation. All glycols produce organic acid as degradation products. The degradation is accelerated in the presence of oxygen and/or heat. Left in solution, such acids lower the pH and contribute to corrosion.

One brand I looked at is Nu-Calgon because my nephew works at a HVAC supply house that sells that and he has heard no issues (used in lots of fixed installations including as fluid in the chillers at a brewery). He recommended one formulation, BUT I found another one specifically for aluminum:

https://www.nucalgon.com/products/glycols/burst-kontrl-ap-100/

Note that Nu-Calgon lists Corrosion Test Results, easy to see which of their products performs best. If we had that info for Century it might be obvious why the switch?

I think any high quality mixture specifically made to protect aluminum might work OK. Just don't mix the sauces!

db_cooper

@N7SHG_Ham ,  I think I saw somewhere that the water heater tank is stainless and the glycol tank is aluminum, but can't remember where I saw it.

fstop32

At the top of page 3 in Corrosion thread @ScottG posted a diagram which along with the text appears to say the heat transfer material for the flame chamber is aluminum and the glycol does come in contact with it.  What the outer layer of the glycol chamber (which is the inner layer of the water jacket) is made of is unclear to me, but the input and output pipes for the glycol sure look like stainless to me.

ScottG

@N7SHG_Ham, what @fstop32 said.  :-)

tybladesmith

FYI Corrosion data from Rhomar Water on mils loss/year for aluminum relative to pH.

Bayliss

@N7SHG_Ham, @ScottG, @fstop32 and @db_cooper, regarding the "aluminum" vs "stainless steel" construction question, see also p. 2 of the ongoing "corrosion" discussion referenced by @fstop32.  Specifically, @ScottG's (second) April 7th (and earlier) comments.

https://tab-rv.vanillacommunity.com/discussion/13226/corrosion-of-alde-convectors/p2

Also, I believe that @Denny16 mentioned in one of his posts that "Paul" (presumably, "The AIr Force Guy") was told by an Alde rep that the water tank has a stainless-steel jacket.  I assume that was mentioned in one of his T@B videos? 

@Denny16 surmised that only the glycol jacket tank is aluminum.  However, he questioned whether the water jacket and glycol chamber share a common wall, or are they separate?