Changing out the Alde fluid.

ScottG · April 2021

Also, while I'm on a tear of organizing things, I moved the comments about alternative draining methods over here from the corrosion discussion.

We seemed to be having one conversation split over two threads, and frankly I was losing track of what I read and said where. :-)

Let's keep the discussion of mechanics over here under one roof, and reserve the other thread for comments specific to evidence of corrosion and efforts to mitigate it.

db_cooper · April 2021

@ScottG
I'm really surprised someone at NuCamp hasn't recommended unhooking that hose to drain more. I remember earlier in this thread or maybe another that the factory was even doing partial drain and fills for owners. I didn't mess with a pump, I wrapped a paper towel around the pipe and used the mouth technique, worked great.

Tampakayaker · April 2021

Does anyone what is the outlet hose and what is the return hose on the reservoir tank? Is the outlet the one that has the lower attachment. I saw a picture of the inside of a reservoir, and it looked like one side had a sunken spot in the bottom.

ScottG · April 2021

I share your sentiment, @db_cooper. My suspicion is that nuCamp was simply following the recommendation from Alde, which was getting the glycol changed at an authorized service center using the proprietary filling pump.

I believe credit for the original blowing-in-the-hoses idea belongs to @Tabulating, who wrote about trying it with success back on page 9. They did something a little different with a 400, but the effect was the same.

That is why this has been such a great ongoing discussion. Incremental understanding and lots of little ideas are finally gelling into simple inexpensive methods for owners to tackle this "mysterious" task on their own!

ScottG · April 2021

Tampakayaker said:

Does anyone what is the outlet hose and what is the return hose on the reservoir tank? Is the outlet the one that has the lower attachment. I saw a picture of the inside of a reservoir, and it looked like one side had a sunken spot in the bottom.

The sunken one directly below the cap is the return from the convectors. The flush offset outlet leads to the circulator pump, which pushes the glycol up through the boiler before returning it to the convectors.

If you trace the hoses, you'll see how they fit with the schematic below.

Image: https://us.v-cdn.net/5021717/uploads/editor/kt/1ibpdm7iimfv.jpeg

Tampakayaker · April 2021

ScottG said:

Tampakayaker said:

Does anyone what is the outlet hose and what is the return hose on the reservoir tank? Is the outlet the one that has the lower attachment. I saw a picture of the inside of a reservoir, and it looked like one side had a sunken spot in the bottom.

The sunken one directly below the cap is the return from the convectors. The offset outlet leads to the circulator pump, which pushes the glycol up through the boiler before returning it to the convectors.

Thanks. I retire at the end of the month then it'll be time to change the fluids. I'm going to attempt to vacuum out the remaining fluid after the initial drain. Will take measurements of what comes out to see if I get all/majority of it out. Have a 320 with the tank in the headboard, seems easy to get to.

fstop32 · April 2021

@Tampakayaker, hope the pic helps. I'm always big on marking things as I pull them apart

Tampakayaker · April 2021

fstop32 said:

@Tampakayaker, hope the pic helps. I'm always big on marking things as I pull them apart

Perfect, thanks.

qhumberd · April 2021

Tampakayaker said:

fstop32 said:

@Tampakayaker, hope the pic helps. I'm always big on marking things as I pull them apart

Perfect, thanks.

Getting ready to embark on my flush and refill on my 2019 400, as reservoir tank is in the closet. Could @Horigan or @ScottG confirm the internal diameter (ID)of the hoses shown? I am using a little submersible pump and want to get the correct size vinyl tubing and barb connectors. And I have 4 gallons of Century fluid already so will flush with water, then distilled water and then the glycol.
Anyone know the sizes of these hoses for the 400? Thanks in advance and I will report back any problems.

ScottG · April 2021

qhumberd said:
...
Getting ready to embark on my flush and refill on my 2019 400, as reservoir tank is in the closet. Could @Horigan or @ScottG confirm the internal diameter (ID)of the hoses shown? I am using a little submersible pump and want to get the correct size vinyl tubing and barb connectors. And I have 4 gallons of Century fluid already so will flush with water, then distilled water and then the glycol.
Anyone know the sizes of these hoses for the 400? Thanks in advance and I will report back any problems.

Internal hose diameter is 22mm. I don't imagine they hoses for the 400 are any different than the 320.

Bayliss · April 2021

See the discussion I posted today re the "Automatic Air Bleeder Valve - Improper Installation." The individual that created the YouTube video included in that thread (Mark Turney) has videos regarding the Alde corrosion issue and changing out the Alde fluid. His YouTube channel is "Tab Trailer Upgrades and Maintenance." I have not yet watched those particular videos, but definitely plan to.

https://tab-rv.vanillacommunity.com/discussion/13423/alde-automatic-air-bleeder-valve-improper-installation/p1?new=1

ScottG · April 2021

@db_cooper (and others if applicable) I'd meant to ask you this before...

Going back to when you first drained the system, how much glycol came out when you first pulled the low-point drain plug (assuming everything else was still connected).

Others have reported getting a bit over a gallon from the low point drain--this makes sense as it would represent the volume of the boiler, the expansion tank, and the short run of hose in between.

However, as per my post of April 11, I could not get the boiler itself to drain until I disconnected the upper glycol hose. Seems there was some sort of vacuum impeding the process. Was that your experience as well?

dsfdogs · April 2021

@ScottG I was able to get one gallon by pulling the low point drain. I did raise and lower the tongue and that helped a little. I noticed at one point when the trickle was waning, I heard a sucking sound and then quite a bit more glycol came out, so apparently that was pressure releasing. I did have a few crystals in the red drain cap and a few more in the drained glycol. I didn't feel any bulges, but can't get to the rear convectors. I didn't pursue the other suggested methods to drain further, above my paygrade, so I refilled and ran the system. I did learn next time to get a long funnel to add glycol to the reservoir as I used a turkey baster and that was painstakingly slow and awkward. I stopped counting how many times I hit my head on the cabinets.

ScottG · April 2021

Thanks, @dfsdogs. Sounds like you encountered something similar but the suction eventually released. I went straight for yanking the upper hose, but maybe if I had tried jostling and patience I would have had the same result as you. :-)

Regardless of what method gets the flow going, I do think raising and lowering the tongue a few times was a good idea. I flushed my boiler core with four gallons of distilled water and it was still coming out a little green so I think some amount of glycol does stay trapped in low spots in the core.

I hope your head is feeling better. That was definitely one advantage of using a pump system to get the glycol in. ;-)

db_cooper · April 2021

@ScottG , I only got a few quarts this last time pulling the plug, so I raised the tongue, got a bit more, then went inside and ran the pump for 15 seconds or so and got a pretty good amount to come out, getting me about a gallon total.

Even so, I think the boiler still holds a few pints, as my distilled flush came out a little yellow.

Bayliss · April 2021

So, @ScottG and others who have done a recent glycol exchange (with the Century Chemical Transfer Fluid), and in light of the recent corrosion and new Rhomar Water discussions, what do you anticipate doing as far a future glycol exchange? Stick with the Century Chemical, or go with a very thorough (hours long) flushing of the system and filling with the Rhomar Water?

db_cooper · April 2021

@Bayliss, I'm sticking with the Century, for several reasons.

One, I can drain 90-95% disconnecting the one hose inside plus the outside drain and refill without a pump.

Two, Rhomar water appears to be difficult to source for the DIYer.

Three, the corrosion I found was limited to the outside of the connections, albeit working it's way through to the inside. The innards look good, so I'm hoping by double clamping and repairing what I found will give me an acceptable ( to me) lifespan of the system.

Denny16 · April 2021

The Century TF should work fine, it was the recommended glycol for the previous six odd years. Just be diligent in changing it out every two years, and Bob’s your uncle...
cheers

ScottG · April 2021

Bayliss said:

So, @ScottG and others who have done a recent glycol exchange (with the Century Chemical Transfer Fluid), and in light of the recent corrosion and new Rhomar Water discussions, what do you anticipate doing as far a future glycol exchange? Stick with the Century Chemical, or go with a very thorough (hours long) flushing of the system and filling with the Rhomar Water?

Good question, @Bayliss. My goal for the last year has been simply to get the glycol changed. The recommended switch to Rhomar Water and the (presumably) related emergence of the corrosion issue was an unexpected complication.

I suspect that more on this issue will come to light in the next year. Hopefully that will include information and guidance from Alde and nuCamp. Now that I have a reliable system for flushing and filling, I'll make the decision regarding the switch at the next go 'round.

The Alde boilers themselves have not changed much since nuCamp adopted them for 2014. It stands to reason that if Rhomar Water is better for the current Aldes, then it is probably better for all Aldes (though why may not be immediately apparent).

The relationship between the Century TF-1 and the current corrosion issue remains unclear (at least to those us in the unwashed masses). I am not convinced that the corrosion would have been completely prevented simply by adhering to the recommended change intervals. For that matter, nor am I convinced that switching glycol will prevent or otherwise reduce future degradation.

While we await further insight, I plan to enjoy my T@B as always and not spend a whole lot of energy worrying about what ifs. After all, I might fall apart long before my T@B! ;-)

RDWHAHB... :-)

RCB · April 2021

I just received an E from Alde that recommends I switch to Rhomar. I have an early 2019 400.

fstop32 · April 2021

Good question @Bayliss and good thoughts @ScottG, @db_cooper and @Denny16. Now (or if/when I finally get my hands on some parts) would be the perfect time for me to swap to Rhomar but at this point I've not been convinced that it is worth the extra expense and hassle. All I've seen so far is we are being nudged to change without any real data to justify the change. Since everything else will be new I could see myself dropping the coins ($50/gal) on enough of the Hydro-Solv to clean out my boiler and then stick with Century and make sure I drain/replace every 2 years going forward.
My T@b got a lot of use by previous owner and it was run on a low thermostat setting whenever it might get cold enough to be a problem. That's a lot of cycles w/o a full fluid change, I suspect that was a large part of what happened to my system. Maybe by the time I'm ready to refill mine we'll have more info on all of this.

ChanW · April 2021

You know, the tilted air separator brings up an interesting point, and I wonder if it's related to the corrosion problem.

The air separator in our Tab has always been tilted, and I knew that was wrong, but I didn't know how much it mattered.

If our systems have a little air catching on the aluminum edges of the convector tubes and sitting there I wonder if that would be enough to cause these corrosion problems.

@ScottG, is your air separator tilted? Anyone else with the major corrosion problem notice their air separator being tilted?

ScottG · April 2021

@ChanW, yes, my air bleeder assembly was a little tilted like other examples documented here. I've never experienced problems with gurgling, bubbling, or heat distribution so I never had any reason to think there was any problem with the bleeder. Frankly I'd be surprised if that was the issue, but that is just a guess on my part (and a weak one at that).

@RCB, interesting--but not surprising--that you got a note from Alde recommending the glycol change. I expect they know something is up and will (hopefully) come clean once they get a handle on things.

There's an old saying "Never do anything for the first time." Aldes weren't introduced to the U.S. market until 2014 (with Roadtrek) and nuCamp wasn't far behind since 2014 models have Aldes. Although the units had been well tested in Europe by that time, regulations over here dictated the use a different glycol. Now, we are starting to see corrosion in some of those earliest U.S. systems--something that was almost certainly unexpected by Alde as it poses a risk to their fledgling U.S. business. It just goes to show you can engineer the heck out of something but time and nature will still find a way to pitch a curve ball now and then.

fstop32 · April 2021

My auto air bleeder was also tilted about 40 degrees. I noticed when it is mounted horizontally the bleeder sticks up slightly above the top of the Alde. I wonder if nuCamp was intentionally mounting it at an angle to avoid it banging into the plywood seat base, they didn't build much of any clearance above the Alde. I'll mount mine horizontally and take a forester bit and drill a bit of relief into the seat bottom.

VictoriaP · April 2021

ScottG said:

@RCB, interesting--but not surprising--that you got a note from Alde recommending the glycol change. I expect they know something is up and will (hopefully) come clean once they get a handle on things.

When they “come clean”, they had best have a solid plan for resolving this. I’m at the two year mark next week. Looking at these posts as someone who has neither the skills, tools, or bandwidth to completely overhaul this system myself just to change the glycol, and at previous posts detailing the difficulty of getting replacement parts since the merger with Truma, I’m honestly wondering if I shouldn’t just trade in my Tab and get something with an industry standard furnace and h2o heater that can be easily and more cheaply serviced or replaced by virtually any RV mechanic in the country. Per the Alde site, the only service centers within 500 miles are at a dealership that doesn’t sell Tabs, and we all know how easy it is to get service from a dealer you didn’t buy from who has little familiarity with your trailer brand. And sorry Alde/Truma, but saying “bring it to Elkhart” as I saw they responded to one person here, is not a viable solution for a large chunk of the population.

The Alde is nice and quiet, but that now comes at a high cost (both from a financial and convenience standpoint) unless you’re fortunate enough to be able to handle it yourself. At the moment, I’d gladly trade that silent heat for something louder with less finicky maintenance, and more readily available service centers.

Denny16 · April 2021

Victoria, isn’t there a TaB dealer in Seattle or Portland area that can do the Alde glycol service? I remember reading here thst one TaB owner found someone in Washington area that could do it. While not as close as a Washington dealer, Vogel RV in Ukahia Calif (TaB dealer for NorCal) does service the Alde units, including fluid change outs. They did ours last summer. It would be a excuse for a road trip...

cheers

VictoriaP · April 2021

Denny16 said:

Victoria, isn’t there a TaB dealer in Seattle or Portland area that can do the Alde glycol service? I remember reading here thst one TaB owner found someone in Washington area that could do it. While not as close as a Washington dealer, Vogel RV in Ukahia Calif (TaB dealer for NorCal) does service the Alde units, including fluid change outs. They did ours last summer. It would be a excuse for a road trip...
cheers

I just saw on another thread that someone in Portland (another location owned by the same Tab dealer as up here) was recently quoted for a Century TF refresh...which to me, seems pretty pointless now that it’s becoming apparent Alde is going to be recommending a full flush and refill with Rhomar. And frankly, I can’t see spending for a Century refresh with what we know...that’s a gamble I’d be much more willing to take if I were able to DIY and easily flush it myself the way I deal with winterizing/dewinterizing. But if I’m going to have to shell out cash and haul the trailer somewhere to get it done, I want it done right. I’m assuming the local dealer will switch to Rhomar at some point once Alde makes it clear that Century is no longer acceptable, but in the meantime I feel somewhat like I’m stuck with an expensive-and-difficult-to-repair system that’s full of a liquid possibly eating away at it.

I’ll have to make some calls when I get a chance. This may just be a “straw that broke the camel’s back” issue, in my case, as there are a number of other things I’m finding I dislike about my rig lately that would all require significant cash to alter (where they can be changed at all), and at some point I have to draw a line. I need to do some more research and some hard thinking, it seems.

Thanks for the Vogel’s recommendation, I’ll give that some research if I can’t figure out a more local solution.

Denny16 · April 2021

Yes, I hear where you are coming from Victoria P. I agree when it is time to change out your Alde fluid, might as well go with the new recommended Rhomar fluid. That is what we will do when it comes due in 18 months. By then, the dealers should have stock of the Rhomar fluid and flush out solution, to,change out the fluid on older systems. A procedure is already in place from Airstream to do this.

I do not think the Rhomar fluid is new, it has been in use for home hydronic systems, and is available from plumbing suppliers who deal in hydronic heating systems. What is new is Alde/Truma US switch to using Rhomar instead of the Century TF.
cheers

pak · April 2021

I'm going to change the fluid next week. After I inspect some fittings I will decide which glycol direction I will proceed. Right now I'm finding the Rhomar products very hard to source and expensive. My dealer has only 3 gallons of Century, in stock. I don't have a lot of confidence in this dealer, which is also the nearest. However well intended, this dealer has yet to show me much knowledge or interest in the 320s. Add this to being over 100 miles away I find that tackling the change myself is worth the learning curve. This site is a tremendous help and resource.

N7SHG_Ham · April 2021

@VictoriaP not sure of your location, I am in Oregon. I too have been researching this. Alde USA suggested maybe Apache, but I didn't check there. Johnson RV in Portland area, while listed as an Alde service center knows nothing about Alde's, so scratch that. Guaranty RV in Eugene area says they can do it confirmed by Alde USA and myself, however I have yet to get that call back with a price they promised. I contacted both Airstream dealers in Oregon, the one in Portland refuses to work on anything that isn't an AS and the one in Eugene says they could, but long wait and the ballpark but not firm price was $800-900. I have considered going to the shop in San Diego area, hey I bought my Tab in Indiana, so road trips are familiar, but it would take a week of time for a procedure that shouldn't be that difficult.

Alde USA didn't think they could sell thier $900 pump to civilians, which seems like a crock of you know what, so I am likely to red-green-duct tape-redneck a pump together for under $50 and see if I can source the Rhomar fluid and do this myself.

I was actually seriously considering buying the pump from Alde, there are three Tabs that I know of in my little town here in Central Oregon (I have talked to both of the other owners), split the cost, I keep pump for future use and we buy a few buckets of fluid and have a DIY party. Honestly this isn't rocket science if you have a way to pump fluid in, not being able to do a gravity drain is a serious maintenance design flaw... Here in the PNW, Gensco (a commercial HVAC wholesale supplier) is listed as a dealer for Rhomar, so that might be a source of the fluid.

I expect Nucamp and Alde likely will be as silent as they can on this issue. A big issue likely fluid change on units going back a number of years plus replacement of corroded convectors probably isn't in their budget as a small manufacturer. I think the NuCamp announcement of the fluid changing in new units is going to be it from NuCamp. Airstream took a very proactive approach, issuing a recall, but likely dealing with far fewer total Alde installs and a much bigger company.

My two cents is Alde knows the Century fluid wasn't protecting the aluminum as well as it should, made the switch to hopefully head off future warranty claims and left it to the RV builders to decide fate of already installed customer base.

I have said it previously here, I don't believe the fluid change was due to some new metal material in 2021 and newer Alde's. I base that on Airstream issuing a recall for all units since 2018 for a complete flush and change, I seriously doubt Airstream did that just because. That move indicates to me Airstream thought it best to get that old fluid out ASAP at their cost before they have to start replacing corroded parts.

Changing out the Alde fluid.

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