Changing out the Alde fluid.

Tabaz · December 2019

Dumb idea of the week - Since the pump already attached to the Alde is able to push the fluid through the entire system without harm, why not just buy a separate one and use that to remove and refill the system?

ChanW · December 2019

@Tabaz , a few thoughts...

An actual circulator pump probably wouldn't suffice for refilling. I think you'd need a pump that's designed for pumping, rather than simply circulating, because it would have more suction/lift capacity, and wouldn't have any problem pulling fluid out of a jug, for example.

Also, I'd like to remove all the old before putting in the new, which would mean inserting said pump into the line at the low point to suck out the fluid, otherwise you could be sucking air, while leaving some of the fluid at the actual low point. I doubt a circulator pump is 'self priming', so it wouldn't handle air very well. Might just as well gravity drain it.

Just seems that way, to me, a layman.

I also like the idea of hand pumping to refill, to have more control over possible over filling.

tybladesmith · December 2019

I think getting a hose clamp tool and after draining the reservoir removing the Alde hose from the top hose down stream of the Auto-bleed valve works. (Note - not mentioned before, I added an Alde 8" x 8" elbow and 1/2" X 3" NPT nipple to temporarily raise the height of the flow out hose. My clamp was not getting 100% shutoff.) And pumping into the hose flowing to the first convector. After PG shows up in the reservoir the circulation pump can be run until it empties. At this point I would try putting the flow out hose back together and filling from the reservoir and cycling the circulation pump, repeating until the air bleeding is completed.

A flush could be done in the same way with 3 gallons of deionized water draining out of the low point drain or until the drained fluid ran clear. That might take a second person to watch the drain for clear water. Then add PG until the color changes back to yellow.

Tabaz · December 2019

Didn’t appreciate the difference between circulating and pumping. I’ll be going away now. When you all get this stuff figured out, have someone draft instructions in plain, non-technical language for those of us in the Unwashed Masses group! Seriously, really do appreciate the work everyone is doing on this.

ScottG · December 2019

Given @tybladesmith's experience, I'm getting the sense it doesn't really matter where you break into the system to pump the glycol. While the reservoir may be optimal because it is the high point of the circuit, access to it may be severely limited in some units.

No need to go away @Tabaz --I pondered the circulator pump idea as well but I suspect @ChanW is correct about its capacity limitations.

I maintain that this really shouldn't be all that difficult. The hard part right now seems to be organizing this big bucket of ideas and info without much definitive direction or empirical evidence. Once we get it figured out--and we will get it figured out--we'll say "Gee, that was easy." :-)

ChanW · December 2019

I agree @ScottG. It shouldn't be that difficult. I think @tybladesmith's idea of clamping one hose shut so the filling fluid can only go one way in the circuit is a key. Otherwise the fluid picks the route of least resistance and doesn't fill the whole system.

I'm almost looking forward to trying it... But then again, I might wait til spring! (Today's temperature in Buffalo is 52°. A bit deceptive! Winter is bound to come eventually, right?)

ScottG · December 2019

Finally tested my glycol this week...

"New" glycol is unused pre-diluted Century TF-1 transfer fluid from an open but mostly full gallon purchased earlier this year.

"Old" glycol was a sample drawn from the Alde reservoir. Except for a cup or two added to top off the reservoir in early 2019, this was the original glycol from my T@B purchased in early 2015. On the last trip of this year, the cabin heat was run for most of two days so the glycol was well-circulated in the system.

Appearance: No obvious differences were evident in color or clarity of the new glycol vs. the old.

Freeze Protection: Tested with a refractometer with a propylene glycol scale. New glycol tested to -16F. Old glycol tested to -14F. These numbers correspond to an approximate propylene glycol concentration of ~46%. (Note that the freezing point is when ice crystals begin to form and the glycol becomes slushy. The bursting point--where the glycol freezes solid and may cause expansion damage--would be below -60F at these concentrations.)

pH (corrosion protection): Litmus paper indicates a pH of ~9 for both new and old glycol. For increased resolution samples were also tested with a laboratory benchtop pH meter. New glycol was pH 9.25. Old glycol was pH 9.6.

The higher pH of the old sample is curious though not necessarily meaningful. The upshot is that the condition of my six-year-old used glycol is nearly the same as a fresh sample with regard to both freeze protection and pH.

This is not to say that there are not other good reasons to change the glycol. There may be additional protective additives in the proprietary fluid that degrade or lose effectiveness over time. Flushing and refilling also helps remove sediment and other deposits from the system.

Lastly--and this is important--note that my Alde gets relatively little use. I camp approximately 30 days per year, and the Alde is turned on to make hot water once or twice a day for less than an hour. The cabin heat is used very infrequently. Heat exposure is correlated with glycol degradation, so YMMV if you use your system with greater regularity.

DougH · December 2019

We suspected a slight increase in pH as well. Curious what the chemical mechanism could be, as the standard worry is a transition in the other direction.

ScottG · December 2019

@DougH, I remembered that you had observed the same thing. I'm not sure if it is a chemical mechanism or just variability in the product.

As an interesting side note, in one of my conversations with Creed regarding this matter, he relayed that Spencer from Alde said pH was important and thought the pH should be around 9.6. Again, not sure if that is meaningful.

Either way, it doesn't seem like the pH changes much, and it certainly doesn't seem like it is going down. Curiouser and curiouser...

AirBoss · December 2019

Really appreciate all the folks chiming in on this topic and all other threads as well. That said, while it strikes me like a bit of paralysis by analysis from time to time there's no question there are ALWAYS nuggets to pack away in ones bag.

New owner of 2020 400 with most all options. Steep learning curve! Thanks to all who take the time to share their wisdom, experiences and perhaps more importantly, their screw-ups. We tend to succeed more when we first fail!

ScottG · December 2019

AirBoss said:

Really appreciate all the folks chiming in on this topic and all other threads as well. That said, while it strikes me like a bit of paralysis by analysis from time to time there's no question there are ALWAYS nuggets to pack away in ones bag.

Ha ha, I agree with you, @AirBoss --it's not lost on me that there are few participants in this lengthy discussion... ;-)

However, questions regarding Alde glycol keep coming up without satisfactory, complete, or consistent answers. We have gotten a lot of great "nuggets" in the process but they have yet to congeal into a set of working instructions. I promise to keep the final product to a one-page TSB! :-)

NomadPilgrim · January 2020

DougH said:

Based on this morning's pH test with a Lowe's $9 test kit with the six-in-one strips versus yesterday's test of the TF-1 fluid, and with my limited use of the Alde, it looks like I should be able to go 47 years before draining and refilling. Refractometer says I'm good. The cell phone pics may not due it justice (lighting conditions not identical, but I used the cell phone camera flashlight feature for some measure of consistency). Brand new fluid looked like 8.5-9.0 to me. And three year old Alde fluid looked nearly identical. Partner and I thought, if anything, the pH and / or alkalinity had slightly increased, not decreased. So no additional glyconic acid here. Woo-hoo! I added a reminder to my calendar for fall of 2063 to replace the fluid.

If it isn't broke...

ScottG · January 2020

NomadPilgrim said:

If it isn't broke...

No argument there. Whether or not to change the fluid at the recommended intervals, test and change it as needed, or just ignore it all together is entirely your business.

However, for those who choose to undertake this basic maintenance task themselves, there should be a simple and economical way to do so properly.

ChanW · January 2020

Well @ScottG, I finally was able to get out there and actually test the glycol. I don't know if it's just my bad record-keeping or what, but after having let it mix for a day with the circulator, it appears I have protection to -32C.

I didn't have a chance to test the pH as my fingers were freezing (will do that tomorrow), but I'm with you if both those figures are in safe ranges - why mess with it if it ain't broke. The Alde has had minimal use in the last two years.

I'll wait to install the second drain tee when I replace the glycol again.

I do appreciate you having inspired me to get after it and check it out. Thanks.

ScottG · January 2020

@ChanW (and others), please report if you find a source for Alde parts. It appears that parts could previously be ordered direct from Alde US, but the newly merged Alde/Truma offers walk-in sales in Elkhart but no phone or internet orders. Perhaps one of their "regional service centers" will fulfill requests, but my first inquiry to one of them has gone unanswered.

Incidentally, emails to support at Alde have also gone unanswered.

This could prove challenging when one of us eventually needs a new part for our unit. Hopefully a workable system will shake out in time.

ChanW · January 2020

Hmmm. @ScottG would this be the point of helplessness where we should contact Nucamp for help in resolving?

ScottG · January 2020

I might send feelers to a few more "service centers" but if the radio silence continues, yes perhaps nuCamp can provide some help or insight.

There does appear to be several options for ordering parts in Europe, where Aldes are presumably more numerous and well-known. Seems we shouldn't have to resort to overseas shipping, however. :-/

ChanW · January 2020

Yes.
Argh. I was counting on that direct line to Alde for parts in the US. I should have jumped on it.

ScottG said:

I might send feelers to a few more "service centers" but if the radio silence continues, yes perhaps nuCamp can provide some help or insight.
There does appear to be several options for ordering parts in Europe, where Aldes are presumably more numerous and well-known. Seems we shouldn't have to resort to overseas shipping, however. :-/

seajeeper · January 2020

I spoke to Alde US in Vancouver, WA a couple years ago when I needed to replace my reservoir. They were helpful and very responsive.

tybladesmith · January 2020

@seajeeper, At the end of November 2019, Alde closed out the Vancouver office and all US operations are now combined with Truma with Main office in Elkhart, Indiana. I did have a good conversation with a Truma parts rep. a few weeks ago. Maybe there is hope if we all keep asking good questions.

gregndeb · January 2020

I'm a latecomer to this discussion. I had discussed last February 2019 with Spencer, the service tech at the time. At that time they would lend a service tool, for a $350 deposit and one would have to just pay the freight both ways. Unfortunately he doesn't work for Alde, since the move to Indiana. Alde also hasn't figured if/how they would do a "loan" procedure.
I did get a manual for using the tool. The tech also mentioned that one could use a couple of Shureflow pumps to cobble up a tool. I've attached the manual and a link that the tech had also provided.
I don't quite understand the 3-position valve. I also think the arrows indicating pump flow appear to be backwards.

I think "A" position draws new fluid from your new container, goes through either one of the Sureflow pumps, pressures the regular supply line at the reservoir. Thus new fluid gets forced in the system, the normal flow direction.
Air is expelled in the expansion tank, as normal. only one pump is used.

"B" position just allows one then both pumps to cycle fluid in the normal direction, at high speed. The directions say to start one pump, wait, then start the other. I suspect they don't want to cause any sudden high pressure to cause damage. It cycles fluid at high velocity, to purge air.

"C" position supposedly allows fluid to drain back to the new container, if your fluid level is too high.

If that's the case, possibly we could figure what type of valve to buy, or make from conventional valves.

Any opinions or knowledge? Here's the link:https://www.youtube.com/watch?v=XwrFfntcQoc&feature=emb_err_watch_on_yt

ScottG · January 2020

@gregndeb, I've seen that video and the manual and I agree it's not 100% clear how everything works, though I still think the diagrams I posted earlier in this discussion are correct with regard to the basic operation.

Though I can certainly see its usefulness in a manufacturing or service facility, I've come to think the fancy Alde pump (or a facsimile cobbled together) is probably unnecessary for a DIY owner who is going to maybe do this once every several years.

Once my T@B is up from its winter nap, I'm going to attempt a complete flush and fill with a hand pump similar to what tybladesmith used. I have an idea for installing a simple fill port in the glycol loop that should allow this job to be completed without having to access and remove the reservoir hoses (which might be very difficult to do in certain models).

Of course, the operative word here is "should"--I can't promise anything until I actually give it whirl. In the meantime, if you want to tinker with making your own Alde pump replica it sounds like a great project, albeit pricey.

I think the valve in question is probably going to be a 3-way valve with a T-port (as opposed to L-port) configuration, though it's possible you could assemble something functionally similar from a series of regular (i.e. cheaper) valves.

Keep us posted!

gregndeb · January 2020

Yeah, I like your diagrams. I saw them yesterday, then scrutinized more today. I hadn't heard of a T-port valve. It makes sense, though the Alde valve instructions appear to be backwards for fill and siphon positions.
What sounds easiest to me is to drain, per Alde spec, then flush/fill with new fluid through the removed hoses from the expansion tank. That could be one pump setup.
Then reconnect the expansion tank and replicate the Alde tool to purge air.
If needing to drain some fluid after bleeding, just take the pump and hose from the first setup and manually drain from the expansion tank.

Expected parts:

1 or 2 pumps (the most expensive part.) with 2 switches)
Hoses to and from pumps
For flush/fill: Adapters to hoses going to expansion tank. (the wonderful world of metric vs. English systems)
For bleed/air purge: Rigid pipe with rubber end (conventional toilet fill pipe with rubber end?), use other hose for pump inlet just drawing from the expansion tank
For siphon, nothing else needed, just take the rigid pipe that was previously being forced in the expansion tank outlet, and direct into a clean bottle to save fluid.

No expensive valves needed. No hassle with trying to fill from a low point. Am I missing something?

ScottG · January 2020

I think what you are suggesting would work. I agree the fancy valve is not strictly necessary--it just facilitates switching among functions when filling an empty system. If you are going to remove the lines from the reservoir anyway (as is required to flush and fill) the three-way valve seems a little superfluous.

It looks like you have a CS, so accessing the reservoir should not be an issue for you. Those with a CS-S or a later model S with the storage under the rear shelf may find getting to the hoses at the bottom of the reservoir is a non-starter. Not the best design from a maintenance standpoint, but you can only do so much in such a small package.

As far as temporarily attaching the pump hoses to the glycol loop, you might be able to get away with a standard 3/4" PEX or other barbed fitting, with a hose clamp to snug it up. The I.D of the glycol hose is ~7/8".

My sense is that there are probably multiple ways of doing this that will all work just fine.

ChanW · January 2020

@gregndeb, be aware that the inlet and outlet ports on the reservoir have been known to break at the tank.

That's one reason I myself will avoid doing it the Alde way, if I can. (Besides the fact of the really cramped working quarters in that part of my non-clamshell Tab)

gregndeb · January 2020

I agree, plastic can get flaky with age. We need someone to make an aluminum expansion tank. Any volunteers?

That said, what about doing the following:
1) Drain from the drain under the trailer. Looking at the diagrams, it will drain the expansion tank, but not much else.
2) Leave the drain open, put a pressure connection to the supply side. Possibly a toilet fill pipe and gasket INSIDE the expansion tank.
3) Push new fluid in the system, expelling the old out the drain. (External pump, manual, electric, whatever)
4) Question here: How does one know when the new fluid has made it through the system? 1 or 2 gallons?? If the color is the same, plus I'm color blind, I'm doomed if I have to rely on color.
5) Once old fluid is out, replace the drain plug. (Probably whilst getting one's hair wet and other fun stuff)
6) continue to fill to MAX.
7) Place the pump intake from the expansion tank. (Just stuff the hose near the bottom.)
8) Run the external pump to purge air from the system. Use the same connection to the expansion tank outlet, but from the tank inside.

Thoughts? It would be a 2-person job, but might be worth it. We minimize adding air in the system, hopefully preventing to bleed much air from the system.

ScottG · January 2020

@gregndeb, if you study the plumbing schematic I posted on page 3 of this discussion, you will see the drain is downstream on the inlet hose running from the expansion tank. If you left the drain open and try to fill from the expansion your new fluid is just going to go right out onto the ground.

We are on the same basic page, though. My thought is to install a filling tee between the drain and the Alde. By clamping the hose between the drain tee and the fill tee, new fluid will be forced through the system and any remaining old fluid will get pushed into the expansion tank where it will then flow out the open drain.

But--and this is an important but--most of this knowledge is based on the layout of a non-CS model. CS models have the expansion tank in a different location (near the front of the trailer) and may well have a different configuration then that shown in the schematic. Specifically, if the low-point drain is located on the hose returning to the expansion tank, what you are suggesting would probably work.

If you (or anyone else with a CS or CS-S who is still following this) could investigate and confirm the location of the drain relative to the glycol flow, that would be a very helpful bit of information.

tybladesmith · January 2020

On a 320S the low point drain is between the expansion tank and the suction side of the circulation pump, before the Alde boiler.

mickietucs · January 2020

Does anyone live in Tucson, AZ that could do this/do you have a pump to get out all the old glycol? I called a Adle Certified Service Center here listed on the Alde site and the guy quoted me $400! I'd rather try to find a T@B personal owner who has done it and work out a price with them. Wish I had talked to someone at T@bazona!

ScottG · January 2020

@mickietucs, I can't help you but I appreciate the info. $400 seems pretty steep given that the only material required are three gallons of glycol that you can buy retail for ~$75. I guess you have to justify the cost of the pump, if they even use the pump. If you look back at this old discussion, even nuCamp apparently doesn't bother with the pump unless the glycol is in poor condition.

My own communications with nuCamp indicate they assess the glycol condition visually--the fluid should not be grey and should retain a metallic sheen. If you were so inclined, you could also check the freeze protection and pH yourself as described earlier in this discussion. If all looks good but you still want to do something a simple gravity drain and fill will replace 1/2 to 2/3rds of the fluid in a typical 320. You would likely need to bleed the system with the auto bleeder and possibly the manual bleed valve, but reports so far indicate this works just fine.

I still maintain this task can be accomplished pretty easily by an owner with an inexpensive hand pump and a few select fittings. However, I'm holding off on writing up a protocol until I have gathered all the materials and had an opportunity to test it myself.

Changing out the Alde fluid.

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