Alde Automatic Air Vent discharge of glycol

[Randonneur]

I took possession of my 2019, still under warranty, 33 Classic in late March. I used it twice for weekend trips and the Alde system seemed to work. The last trip was this last weekend, returning home on Monday morning. On Tuesday I left for another trip that was about 3.5 hours away, much longer than the other trips.
I started up the Alde system and found that I had an “Overheat red fail” message. I found the expansion tank and could see NO glycol. Since I have had the system only for about six weeks, it had not occurred to me that I needed to carry extra glycol. I also noticed something dripping below the tank—not water. I read through what documents I had and then decided to call the dealer in the morning, as it was late by this time.
Wednesday I spoke to Erich Nelson at Woodland Airstream in Grand Rapids. He told me that what I really needed was that glycol, so I ordered some overnight, as there are no dealers within a three hour drive of here. Thursday it arrived. I added enough to get the tank above the minimum line, and the drip began again. It was coming from the Automatic air vent on the system. I began collecting it, not desiring to add to problem. The error message remained. Erich sent me the list of bleed points and I bled all but the one under the galley, as I could not reach it. I also cranked up the stern and then the bow to get any air pockets to move.
The error remained.
I called JC and spoke to John. He could add very little to what I already knew. Why was the automatic air vent dripping out glycol?
With the error still in effect, but having seen something about disconnecting the 12V power supply, I called Truma and spoke to a service tech there. He told me to disconnect said 12V power supply. After a couple of false starts, I turned off the panel breakers (that alone was insufficient), turned off the shore power at the connection, and held down the button for battery disconnect (that was the key, but I could not find anything that actually said that, though perhaps that was user error). I topped off the expansion tank to the appropriate level and waited 15 minutes. I turned everything back on and the message was gone and the system began cycling again. Hurray!
However, the dripping continued, which was source of the problem. But what was the source of the dripping? I continued to collect glycol, up to about $25 worth(including shipping), or a quart, depending on your measurement standards.
And, for no reason I can determine, about 8 p.m. Thursday evening the dripping stopped and has not restarted as of this writing on Friday at 11 a.m.
Why was the automatic air vent dripping out glycol? Thoughts?

[BigSxyWhtGuy]

I googled your part as I haven’t had much issues with it in the past. That is a serviceable piece that is prone to failure. There are a few YouTube videos about it and other forum topics on SOB trailers.

When we swapped to the 3020 unit, the Truma tech actually disassembled all the parts that are reusable and pointed specifically to this valve as a useful backup.

You may need to replace the valve if you can’t get it to stop leaking.

[Randonneur]

Thanks. It did stop, I hope for good. I found the whole episode puzzling, why it started dripping and why it stopped. If it failed, you would think that it would continue to fail, but I am no engineer so perhaps I’m not clear about how these things work.

[BigSxyWhtGuy]

Was your unit impacted by the recall? The liquid should be clean. No particles in it, but the recall was done because of the liquid conducting electricity and weakening the welds. When the welds weaken, sometimes debris begins to circulate. I would image if debris got stuck in the valve it was cause it to stay open until cleared. Just a guess though.

[Randonneur]

If you mean the flush that they did, yes, the dealer performed that maintenance. The original owner seems to have been a friend of the dealer and so, until my purchase, everyone knew everyone.

[BigSxyWhtGuy]

Yes, should have been a flush and the addition of a ground wire. You can see the ground wire addition on the front side of the unit.

[Randonneur]

I will look for the ground wire. In any case, as soon as I started towing home it began dripping glycol again and the reservoir shows no glycol visible, just like the last time. I know now to add more glycol before booting up the system, but instead plan on dropping it off at the dealer for warranty repairs on same, as well as testing the rear AC unit (which does not seem to cool) and test the batteries, which get low voltage warning from the CZone panel. I hope that these issues are not an ongoing issue.

[uncle_bob]

Hi

Sounds like the air vent is broke and needs to be replaced. You might have another leak. Taking the system down to zero quickly is losing a *lot* of glycol.

Bob

[Randonneur]

The amount of glycol that is visible up to the minimal level is probably about 12 to 14 ounces. I cannot make a qualitative assessment of that amount, as I do not know how many ounces the entire system contains, but it must be quite a bit more than that. Any case, as the unit is still under warranty, I will let the service center try to figure it out.

[uncle_bob]

Originally Posted by Randonneur

The amount of glycol that is visible up to the minimal level is probably about 12 to 14 ounces. I cannot make a qualitative assessment of that amount, as I do not know how many ounces the entire system contains, but it must be quite a bit more than that. Any case, as the unit is still under warranty, I will let the service center try to figure it out.

Hi

The system contains several gallons of the aluminum friendly / heating grade glycol and distilled water mixl.

Bob

[Randonneur]

Thanks. No doubt that there is quite a bit. The original dripping discharged enough for the glycol to no longer be visible in the tank, but just barely, as it rose to a visible level almost as soon as I added some. I collected about a pint and a half under the trailer as I did not want it to discharge on the ground.

[WA_Airstream]

We had a 2018 33 Classic that did what you describe for 3 camping seasons. The dealer tried almost everything to fix it. It would work great for 2 trips and then drip consistently for the next trip ….

I hope yours is fixed and doesn’t start doing it again.

[Randonneur]

Thank you. Well, I suppose misery might like company in other settings but I am sorry that you had the same issue. The dealer could not find the problem on mine. They tipped up one end and then the other to see if it was an air pocket issue. No joy. They turned off the day/night programming as well (no technician that I have encountered seems to like the idea of a programmable thermostat).
I find that if I simply check the glycol level before turning on the system, topping off as necessary, I get a working system. This is not as it should be, obviously. However, as long as it only costs me 16 oz. of glycol each camping trip, I will simply write it off as the cost of doing business. That is about a gallon a year for my camping season. Taking two days to bring it to the dealer (drop off and pick up) and pay them to find nothing is a poor use of my time.
You list a 2018 Classic, do you still have it or is it replaced?

[BigSxyWhtGuy]

Have you tried reaching out to Truma yet? They may have a service center close that can check it out.

[no_worries]

I have a similar problem. Just had my Alde system flushed. First trip after the flush, the black hose under the boiler started dripping Alde fluid (never dripped before). Interestingly, it only drips while in motion or shortly after motion. Once the trailer is setup at campsite, it stops dripping after a period of time. I was losing a full reservoir of fluid per 400 miles.

Dealer has identified the problem as an automatic bleed valve stuck in open position. It will be replaced tomorrow. I will provide an update.

[Randonneur]

Sorry for the delayed response. I’m wondering how it’s working out now that they have replaced the overflow valve?

I returned from a camping trip a week ago it was about 45 minutes drive and found that this time it did not leak, at least in the return.

I plan on reaching out to Truma next week.

[Randonneur]

I have found that if I release the pressure on the water, through the discharge valve underneath the banquette, I no longer have a problem with the overflow valve and glycol leaking. This is worked well for almost 3 months.

[RickyNelson]

Hi Eric - per your last post your situation with the leak improved for several months. Is your process of releasing the water pressure still working to resolve this issue? If so, which release valve is it, if you don’t mind sharing?

I am having the same issues. The colder the travel weather, the more glycol I need to replace.

Thanks for all the information!

[Randonneur]

I found that the problem did return after a while. In the spring of 2022 I put the unit on the list for service with the mothership, but could not get an appointment until the end of the 2022 camping season. At that time, in addition to a number of other repairs, they replaced the overflow valve underneath the forward banquette. I put the unit in storage for the winter and sold it without ever using it again. I’m sorry that that does not allow me to help you more than that.

I enjoyed the unit very much and it was very comfortable, but the requirements of taking it out were demanding enough that I decided that it no longer fit with my schedule.