Changing out the Alde fluid.

webers3

Easy, right

db_cooper

Adding fluid to the glycol tank is a pain, literally.  Removing the tank to flush, not going to happen.  I'll buy a new Alde when it corrodes!

N7SHG_Ham

I am not so afraid of the pump contraption as I am the cost, a few hundred pounds on GB dealer web pages.

I think if Alde makes that pump assembly available for loan it will be quite simple to do a proper flush and fill.

webers3

db_cooper said:

Adding fluid to the glycol tank is a pain, literally.

Turkey baster

lkc001

I just can't see taking everything apart in a severely confined space to hook up a pump and then getting it all back together again.   I don't think that would be "simple".  It was my understanding from research I have done that you have to tank the tank off to hook up the pump.

lkc001

I think I'm in the DB Cooper team. . . . . and still no clear guidance or instructions from Nucamp on how to do this.

ScottG

To clarify my earlier statement, I was suggesting it was conceptually simple. Basically you pump new fluid into the heating loop until you have completely displaced (and forced out) the old.

As for gaining access to the Alde reservoir and its associated plumbing, that may be a different story...  ;-)

Personally, I really don't anticipate detailed instructions from nuCamp or Alde will be forthcoming (though they may have something to add to the conversation). Those of us who care to do this maintenance ourselves are going to have to put our thinking caps on, figure out a plan, and give it a try!

Tabaz

Would using just the bleed valve to empty the system work?  Put a small bucket under the bleed valve, open it. Turn on the pump and let it bleed.  I'm guessing one downside is running the pump dry.  

ScottG

Unclear, @Tabaz, though I doubt it as the bleed valve is not at a low point in the system. I'd be more inclined to try this with the actual glycol drain, though your concern regarding running the pump dry is probably legit.

I'm still not clear why just opening the drain under the camper doesn't let all the glycol out. As best I can tell, it's the low point in the system which--at least in the 320--is not terribly complicated. However, enough members have tried it and confirmed that they don't get the expected quantity from draining alone. I wonder if there are some backflow prevention or perhaps isolated pockets in the guts of the Alde itself that prevent complete draining. 

ScottG

Here are a some older threads that might be of interest:

https://tab-rv.vanillacommunity.com/discussion/8019/alde-glycol-exchange/p1

https://tab-rv.vanillacommunity.com/discussion/2360/anyone-attempted-a-glycol-exchange-on-alde/p1

Let's try to keep any new comments over here on this more recent discussion. As time permits I'll start consolidating what we know (and what we don't know). Maybe we can eventually organize all these bits of info into some workable DIY plan for getting this job done!

ScottG

Ok, here goes... 

I've started compiling my notes based on numerous forum comments and my own research. Before you can solve a problem you need to define the problem, and is this case there are several.

Replacing the Alde glycol can be broken down into four components, each presenting its own challenges:

1. Remove the old glycol.  The T@B Alde system is reported to hold 3+ gallons of glycol. There is an apparent low point drain in the system, but multiple users report that removing the plug only results in a gallon or so draining via gravity. The remaining fluid remains in the system either trapped in pockets or prevented from draining by check valves. Where exactly the non-draining fluid is located is unclear, so the effectiveness of incorporating additional drain points cannot be predicted.
2. Fill with new glycol.  Some owners have attempted to do this by pouring new glycol into the expansion reservoir and allowing gravity and the circulator pump to refill the system. While this approach may work, it appears to be slow and inefficient.
3. Bleed residual air from the system. North American Aldes incorporate an automatic air bleeder. There is also a manual bleed valve located on the rear fin-tube convector. Owners who have gravity drained and then topped up their system seem to report successful bleeding by simply running the circulator pump and using the existing bleed valves. It’s unclear if this approach is sufficient for bleeding the system after a complete glycol exchange.
4. Accessing the equipment.  Most glycol exchange methods will involve needing to access the glycol expansion reservoir and its associated plumbing. Ease of such access will vary on different units, but is likely to be challenging on T@B 320s where the reservoir is either behind the rear cabinetry or (in the case of CS models) behind the bathroom wall.

Please to add to this if you think of something I have not covered here. The next step--which will likely take some time--will be to research and evaluate possible solutions.

Bayliss

@ScottG, thank you for the simplified summary of information.  I copied it to my voluminous T@B notes and appreciate it very much.

I wonder if the lines would drain better if the glycol fluid were slightly warm?  I have never seen that suggested, but maybe it would help.  I'm guessing that the extra fluid is simply remaining in the lines, just like water remains in the PEX lines and has to be blown out.  (With the Alde, you are essentially doing the same thing, but pumping out the old fluid as you replace it with new fluid.)

My 320S is only a year old, so I have not yet had the need to drain my system and replace the fluid.  However, since I have not had to use the Alde too much, I'm thinking I will not need to completely "drain" it every two years.  Even if I do change out the fluid every two years, maybe I can merely drain some and refill the reservoir, assuming the fluid appears to be OK visually.  I am aware of the possibility that it may degrade the Alde system if I do not perform a complete drain and replacement fill, but I really question that concern if the Alde is not used on a regular basis.  I do maintain the radiator and other systems (oil, brakes, fluids, bearings, etc.) on my personal vehicles at the manufacturer's recommended intervals, but I use those systems on a daily basis, so I tend to view the Alde differently (rightly or wrongly.)  Standing by for the criticism of this view.

TabberJohn

ScottG said:

Please to add to this if you think of something I have not covered here. The next step--which will likely take some time--will be to research and evaluate possible solutions.

Determine if 5 year lifecycle glycol (the new std in EU) is available for the US market and where to source it.

Sharon_is_SAM

@Bayliss, I think the concern regarding the old glycol is degradation of the anti-corrosion inhibitors.  I read that, in a closed system, the glycol itself takes a very long time to degrade to glycolic acid.  But, not sure if our system is actually considered closed.  

db_cooper

FWIW, I contacted Nucamp and the reply I got said that the drain is the low point, and tipping the tongue up would drain most of the glycol.  I did drain it with warm fluid.

I've only gotten about a gallon each time doing it this way. I'm skeptical that there is much more glycol in the system. Just eyeballing the short run of  hoses I don't see room for 2 or more gallons.  I still need to follow the hoses to make sure it's the low point, but I'm ready to call this maintenance item done.  We use our Alde quite a bit, so I may drain and fill more frequently, since it's cheap and easy to do this way.

ScottG

@db_cooper, in one of those older discussions I linked to above, nuCamp makes the same recommendation if the glycol currently in the system tests "good."

This is a bit lost on me, since if my glycol tests "good" than I feel little compulsion to go through the trouble of changing any of it...

The 3+ gallon capacity also came from nuCamp, but I have no independent confirmation. Alde's literature claim the Alde itself holds just under 1 gallon. However, as I stated above, it's unclear what parts of the system are not getting drained.

Now that I've got some questions organized, I plan to engage in conversation with the nuCamp folks and Spencer at Alde to try to get some clearer answers.

When all is said and done, I may end up just doing what you do. However, since the glycol in my system is going on six seasons, if I'm going to bother to change it I'd like to be confident that I am changing all of so I can go back to ignoring it for several more years.  ;-)

ScottG

@TabberJohn, another video I watched used Cryotek-100. I'm not sure if this is any better than the Century fluid. My understanding--perhaps wrong--is that the high-test stuff used in Europe is prohibited in the U.S. because of its increased toxicity.

ScottG

@Bayliss, you are welcome--I'll keep expanding and sharing the notes when and if I get more relevant info to add.

I doubt that heating the fluid would make much difference. This is a common practice with viscous substances such as motor oil, but the Alde glycol is already pretty runny.

I'm not prepared to criticize your view regarding the rate the fluid degrades under light use, as I tend to share it. Many maintenance recommendations are very conservative--it certainly won't hurt to do them if you are a belt-and-suspenders type, but the sky is unlikely to fall if you stretch things a bit. I can certainly understand why some members say they are not going to bother with this unless and until it's a problem, and then they will fix/replace as needed.

TabberJohn

ScottG said:

@TabberJohn, another video I watched used Cryotek-100. I'm not sure if this is any better than the Century fluid. My understanding--perhaps wrong--is that the high-test stuff used in Europe is prohibited in the U.S. because of its increased toxicity.

Looks to be a spendy endeavor to replace 3+ gallons worth, but I think it's this stuff --
https://www.amazon.com/RAVENOL-J4D2003-1-Coolant-Antifreeze-Premix/dp/B017THVU0U/
https://www.amazon.com/dp/B077P4R4V7
It's likely available from a VW/Audi/Porsche dealership as well -- at an even higher price.
Also available as a concentrate (1:1) you'd need to mix equally with de-ionized water.

N7SHG_Ham

https://www.youtube.com/watch?v=Mg-Z02QmT90

Tabaz

I purchased the Cryotek last year after watching a UTube video.  However, the container says it is NOT compatible with aluminum systems.

tybladesmith

Here is an Alde YouTube video on testing of the European G13 antifreeze. Obviously the Century TF-1Transfer Fluid often found in USA T@Bs is different than shown in video, and non-toxic (GRAS) generally recognized as safe. "Century recommends professional system preparation and fluid introduction."Century recommends testing PH every 6 months. PH should be between 7 and 8. Haze point (first ice crystals observed) (-34F)
https://www.youtube.com/watch?v=znf7EOJnvLY  

ScottG

Tabaz said:

I purchased the Cryotek last year after watching a UTube video.  However, the container says it is NOT compatible with aluminum systems.

Good to know. I don't know to what extent this is a concern with the Alde, but I'll probably just stick with the nuCamp recommended Century Transfer Fluid so there is no question about compatibility and needing to flush the entire system completely.

My bigger concern at the moment is figuring out how to make the exchange, not so much what to exchange with.

RCB

Further to my suggestion to drain some then add some...the trick is to get out as much as you can without having any histrionics. If it is that hard to drain the system there is something basically wrong with the design of the system. Having said that, there are a number of inexpensive liquid extraction pumps on amazon that might help in the draining process. Me, I plan to drain what I can, then fill it back up with the Century product. The fluid in the system will be a dilution and therefore a reduction in amount of spent coolant. 

ScottG

RCB said:

...

Having said that, there are a number of inexpensive liquid extraction pumps on amazon that might help in the draining process.

...

Yep, that is the general idea I'm toying with--pump it in one end until you collect the desired volume from the other. This assumes I can get reasonable access to the hoses at the reservoir, and that the system is able to self bleed after a complete exchange.

ScottG

I knew this schematic would come in handy one day! I think it provides a clue the where the missing glycol is lurking after pulling the drain plug...

It looks like pulling the plug alone would drain the expansion tank, most of the Alde itself, and the short stretch of hose between them. Based on information about the Alde capacity and seat-of-the-pants guesstimating, I'm thinking this would account for the 1+ gallons reported by several owners.

The convector loops would effectively be blocked by gravity on both ends, since the connections at both the expansion tank and the Alde represent high points in the system.

If I'm right about this, it's easy to see why a pump applied to the outlet side of the expansion tank (as was the case in one of the videos posted previously) would force the remaining glycol in the loop back through the Alde and eventually out the inlet pipe at the tank.

(12/24/19: Photo edited to correct labeling.)

ScottG

And more good info...

The newer Alde 3020 manual is a bit more descriptive than the older 3010 many of us have been working with. Sections 1.10 and 1.11 provide expanded info and instructions on filling and bleeding the system without the Alde pump. In summary, it appears the auto bleed valve is sufficient for bleeding the system after a complete refill. If the automatic breeder fails to complete the job, there are also instructions for bleeding the system with the manual valve(s).

With regard to glycol circulation, I don't see any obvious differences between the 3020 and the older 3010.

Operators manuals for both units are available here.

Michigan_Mike

Here is some information and recommendations from Austin Jones at the nuCamp repair shop....  In a nutshell Austin recommends that owners have this task done professionally and via a certified repair person to eliminate damaging your unit and protecting your investment.  Don’t shoot the messenger.  😀👍🏻

Alde & myself recommend using the proprietary pump to pump the fluid out of the system while pumping new in much like a transmission flush. This alleviates the need for a time extensive bleeding prosses and a lot of frustration. If you do not have a pump it is almost impossible to get all of the old fluid out of the system by just draining it out of the low point drain through the floor leaving sediment & tired old fluid in the system. Once you are refilling the system it may help to turn the pump speed up to max for a bit to help push the air bubbles out quicker. The glycol can also be tested via PH paper to see the quality of the glycol as well if you are on the fence about changing it. Sometimes the glycol can last several years if it is not used much. 

Alde has a great video on YouTube:

https://www.youtube.com/watch?v=XwrFfntcQoc

The biggest thing to watch is if you are bleeding the system to unplug the 110 plug so that in the event of the system calling for heat on shore power it will not burn up the heating elements if there is not adequate fluid in the Alde.

Final thoughts. If you are questioning your capability pay to have this service done by a professional. If you are doing the change with out a pump drain it the best you can, unplug the 110 line to the Alde to avoid the system kicking on & cooking the heating elements. Only use Century transfer glycol or Alde’s brand of glycol.

Thanks, 

Austin Jones

ScottG

That's good info, Mike--and a little contradictory to other info that has provided by nuCamp in the past. Austin's general summary is essentially what I have in mind after consulting numerous sources--pump in new fluid under pressure to force out all of the old, and turn up the circulator to help purge the air via the automatic air bleeder. 

Regardless, my concern is less about paying to have it done than it is about having access to a qualified shop to do it. Frankly, I have much more confidence in my own abilities than I do in the average RV service department (most of whom may have never even seen an Alde).

It's interesting that Austin seems to be confirming my suspicion that degradation is accelerated by use--probably an effect of repeated heating cycles. He mentions checking the pH, but doesn't say what an acceptable minimum pH is. I've been trying to get a bead on this for the last two days, but so far neither Century Chemical, nuCamp, or Alde has provided a definitive answer. If you can get something out of Austin, do tell...

(And the video he provided is one I linked to earlier in this discussion. It is short but very informative about the basics of pump-facilitated glycol replacement.)

ScottG

In my quest to unravel the Alde glycol mystery, I stumbled across this web site from the UK. It provides some pics of corroded Alde guts. The part shown appears to be the inner wall of the glycol chamber, which would surround the propane burner. A leak here would spill glycol into the burner chamber, while a leak on the outer wall would spill glycol into the domestic hot water tank.

Not that everyone should immediately panic. This is the site for a caravan service company that maintains Alde boilers--the corrosion shown probably represents a worst case scenario of prolonged neglect, and as such it makes a good marketing tool. Regardless, this should give pause to those who choose to ignore glycol maintenance completely. We're not talkin' a little surface rust here, but rather full-blown holes resulting from what looks like acid burns on aluminum!