Glycol questions

Dana · April 10

I have a 2021 Tab 320 CSS. Questions;
1. How full is it supposed to be?
2. Do I have to flush every two years or can I top it off? I don't think it ever has been on either count)
3. It has the new blue stuff, where do I get it? Does it come pre-mixed with water?
4. If I have to flush it, I don't know how. No dealer near me will respond.

bergger · April 10

1. There is a minimum and maximum line on the expansion tank. Fill it just over the minimum line when cold.
2. The rules say to drain and refill every two years. Mine is due this year but I'm debating on doing it every three years. But check in on occasion during the camping season and top it off if needed.
3. NuCamp dealers will sell the Rhomar glycol and there may be some online sources as well. The dealers get stock from NuCamp and it comes pre-mixed and ready to use in 1 gallon jugs.
4. If you already have the Rhomar in your trailer, the blue/green stuff not the bright yellow stuff, you should be fine draining and refilling. You do not need to flush it out with water. This is only needed if making the switch from the old Century glycol to the new Rhomar glycol. There is a very long thread on this site about methods to flush the system on your own or on how to replace old Rhomar with new. Basically the same method just no initial water flush.

Sharon_is_SAM · April 11

@Dana - are you saying the local TaB dealers can not do the Alde maintenance? Check with local Airstream dealers as some of their trailers have Aldes.

Sunfellow · April 14

Does anyone have an online source where Rhomar glycol can be purchased?

Sunfellow · April 14

Also, does anyone know when nuCamp/ALDE starting using the Rhomar Glycol formula? I have a 2022 T@B 320-S Boondock. I'm wondering if that was the glyco that was used in my T@B? The previous T@B owner never checked the glycol levels which are getting low now.

I'm also wondering if I need to flush the system before adding more glyco or if I can just top it off? Does the Rhomar Glycol formula keep its potency longer than previous glycol versions or does it loose its potency over time?

Thanks!

MarkAl · April 14

I think this is what we use, I'm about to order 3 gal. Amazon.com: Truma Alde Glycol | Premium Heat Transfer Fluid for Optimal Corrosion Resistance | Protects Heating System Components | Suitable for All Weather Conditions | Eco-Friendly Formula : Automotive

pthomas745 · April 14

This is a link to the NuCamp "announcement". The trailers after "about" December 2020 came equipped with the "Rhomar" type glycol. Rhomar is a bit difficult to find, but apparently some owners have managed to do it.

We can only guess that the "Truma Alde Glycol" on Amazon is the "Rhomar" simply poured into a nice Alde Truma bottle and marked up. NuCamp sells what apparently must be the same thing in semitransparent bottles.

So, you must go by your "Build Date" and what your own eyes tell you when you look into your Alde expansion tank.

https://nucamprv.freshdesk.com/support/solutions/articles/44002156353-2021-glycol-change

Sunfellow · April 14

Thanks for the prompt and very helpful responses

pthomas745

MarkAl !

Do you have any idea how long the new Truma Alde Glycol lasts? Does nuCamp/ALDE continue to recommend this be changed every couple of years or does it last longer now?

Also, I believe there was mention of a test in previous forum posts that can be used to determine the potency of the glyco in the tank? Do you know what this test is and if it applies to the new "Truma Alde Glycol" fluid?

Thanks for your help! This forum (thanks to knowledgeable people like you) is super helpful!

Sharon_is_SAM · April 15

@Sunfellow - Alde/Truma and nuCamp still recommend every 2 year drain and fill with new glycol. There is no test for the ability of the glycol to prevent corrosion.

Sunfellow · April 15

Thank you!
Sharon_is_SAM

Sunfellow · April 15

One last question (I hope). Where is drain valve for the glyco line on the 2022 T@B 320-S Boondock?

pthomas745 · April 15

Look under the trailer, driver's side, and you will find several drain "spouts" down there. The glycol drain is the one with the "cap" secured with the hose clamp.

The glycol "test" you might be thinking of was probably the mentions of the pH balance of the glycol. Like everything else about the glycol, this is an enigma wrapped in a mystery. Alde isn't telling.

We have had an ongoing discussion about the Alde, the glycol, the corrosion causes for almost 7 years now. It seems like having read these threads over and over, some of us might be approaching the PHd level in Alde chemistry. The only way to get up to speed with this subject might be to go back to the beginning and see what has been discussed. It will be worth it, and answer many questions. A quick skim through it will help you find the discussions and measurements about the ph balance of the glycol..which turned out inconclusive. So..start here.

https://tab-rv.vanillacommunity.com/discussion/2665/changing-out-the-alde-fluid/p1

Corrosion of the Alde convectors for the "early Alde trailers" has been another long term learning issue. Another long thread, but the group seems to think any corrosion had little to do with whatever glycol was in the trailer. Or the ph. It might have been just the way the hoses were clamped to the convector ends. This is another thread with plenty to think about.

https://tab-rv.vanillacommunity.com/discussion/13226/corrosion-of-alde-convectors/p1

Robermcm · April 15

this is an enigma wrapped in a mystery….surrounded by a riddle!

Sunfellow · April 15

Looking under my T@B, I found a sealed box on the driver's side nearest the tongue (do you have any idea what that's used for?) and two drain spouts on the rear of the T@B near the grey water drain valve. I'm assuming one of these spouts (or maybe both of them?) is how the glycol is drained out of the system? Are these the spouts I am looking for? And if so, why are there two of them and how are they used?

bergger · April 15

In 2022 they added two lines (spouts) for the glycol system where earlier models had just one for draining. The newer ones have a drain line and a line to add glycol. The dealers have a pump from Truma/Alde where they connect to both lines at once to add new glycol as the old is pumped out of the other line. Since I have a 2021 with a single drain line I do not know which line on yours is the drain and which is where new glycol is pumped in. Maybe if you removed the plugs from both they would both drain? Or one may have a check valve that only allows glycol to enter and not drain out? Hopefully someone with a 2022 or later trailer will know the answer to that question.

As far as the sealed box by the tongue that you found, do you have a photo of it?

Sunfellow · April 16

Thanks bergger and pthomas745. Here's what the sealed box looks like...

pthomas745 · April 16

I believe that is a box to cover your shower drain or drain trap. I have pictures somewhere, but now that google search has gone bonkers, I can't find anything any more!

Sharon_is_SAM · April 16

Agree with pthomas745. That should contain the shower trap.

ScottG · April 16

I believe that double drain is just two drain stubs connected to a single short length of heater hose. Those appeared after Alde changed their proprietary service pump to a "bottom fill" design rather than requiring access via the expansion tank. I'm not sure exactly how the bottom fill pump works, but I suspect it involves a clamp between the two drain stubs. I don't think there is a check valve between the drains, so either or both could be used to drain the glycol.

If I'm wrong about this and someone who actually has the two drains can set the record straight, please do so!

Robermcm · April 16

Both drain ports are circled. Each to one side of that metal hold down clip. No apparent one way valve between them. Might be a one way to the right of both of them. That’s upstream.

bergger · April 16

As far as the black box @Sunfellow has on the drivers side near the drain I still am not sure what that is. I have nothing like that on my trailer. It seems too far forward for a shower trap and unless they changed the design after 2021 the shower trap should be contained inside the trailer above the floor. Ours is and is visible when you remove the access panel under the bathroom door.

Sunfellow · April 16

I wrote nuCamp about this situation. Here is my correspondence with them (April 16, 2024):

Good Morning nuCamp People,

I just called your tech support department and the recorded message said I could email you my questions. I have four.

1. I recently bought a 2022 T@B 320-S Boondock and need to know how to flush and refill the glycol from the ALDE system. I found the glycol refill container and the two drain spouts but am unsure how they work. Can someone please describe how to flush the old glycol out of the system and add new glycol? It's my understanding that the system should be flushed and refilled every two years.

2. I believe the glycol you recommend is this one:

Truma Alde Glycol

https://amzn.to/3Jmgizq

Is that correct?

3. The ALDE manual doesn't specify this particular brand, which is $57.00 a gallon! Instead, it recommends a simple 60% distilled water / 40% propylene glycol-based boiler antifreeze, which is less expensive. Can you recommend a generic version of this anti-freeze that plays nice with aluminum and stainless steel heating systems that also contains the multi-metal corrosion inhibitor additives? I plan to use the recommended Truma Alde Glycol version (assuming that is the version you recommend), but I would also like to know the name of a generic version I can use if I can't get my hands on the recommended version.

4. Last question: Why does the glycol need to be changed every two years? If you use the ALDE system less, does the glycol last longer? And what about using the Truma Alde Glycol brand versus generic versions? Does the brand name glycol last longer than generic versions?

Thanks for your time and help! I love my new T@B and look forward to learning how everything works so I can take good care of her...

..............

Creed Hostetler, nuCamp Technical Support Specialist answers:

Hi David!

1. We only recommend having the glycol flush performed at a nuCamp dealership or RV service center that has worked on Alde components. It will also require an Alde pump in order to push the glycol through the lines. So we won't be able to provide DIY instructions for a Glycol Exchange.

2 & 3 . Per Truma/Alde, we can only recommend the Truma Glycol. If you would like, you can contact Truma/Alde directly to see if they would approve the use of another brand. Here is my contact at Alde:

Chantal Hershberger

Senior Customer Care Coordinator

(855) 558-7862, Ext: 113

c.hershberger@trumacorp.com

4. Good question - we are only approved to use the Propylene based Glycol - which has a rated life of 2 years. Once the glycol is exposed to the system, the additives such as corrosion inhibitors slowly break down over time, even if the Alde is used less than normal. In Europe, Alde uses the ethylene glycol, which is rated for 5 years.

Best Regards,
Creed Hostetler

nuCamp Technical Support Specialist

Sunfellow · April 16

The rectangle box is located directly under the shower drain, so it makes sense that it is the shower trap.

ScottG · April 16

Well, this is interesting. In addition to the double glycol drain, there's also a different expansion tank for use in "bottom-filled" systems. @Robermcm and @Sunfellow, do your expansion tanks look like the one below with a single outlet, or are they the more typical two-outlet design found in older T@Bs?

Image: https://us.v-cdn.net/5021717/uploads/editor/ah/onk3j2sbpzfp.png

Sunfellow · April 16

My expansion tank has two small tubes coming in at the top and two larger hoses on the bottom...

Sunfellow · April 16

ScottG · April 16

Thanks, @Sunfellow. That's the original style tank, which was what I expected. At the very least it means the current DIY glycol change methods should still be applicable.

bergger · April 16

Sunfellow said:

The rectangle box is located directly under the shower drain, so it makes sense that it is the shower trap.

I just remembered you have a 320 and not a 400! I had the 400 stuck in my head when looking at your photo.

bergger · April 16

The location of that expansion tank certainly does make it harder to do the method that I used to flush and changer out my glycol. However with the added drain tube they now have I bet it will be even easier. Attach a pump to one tube and a shop vac to the other and you should be good to go.

Sunfellow · April 16

Thanks bergger . Very helpful! That's what I'll do. There's no way I'm dragging my T@B to a dealer to have this done for me, especially since the nearest dealer in my case is over 120 miles away...

ScottG · April 16

bergger said:

...
Attach a pump to one tube and a shop vac to the other and you should be good to go.

Maybe, but I'm not certain this won't result in just pumping glycol in one hole and sucking it right back out the other.

I confess I can't figure out exactly how Alde's bottom fill method works. Unlike the original Alde service pump (which connected through the expansion tank) there are no operating manuals, videos, or other resources to be had.

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