Changing out the Alde fluid.

Carsoncitysmith

Strategic retreat:  Having added two gallons of distilled water and gotten back one gallon +/- of dilute glycol and not seeing a clear path to completing the replacement, and expecting a hard freeze tonight, I refilled the Reservoir with the old glycol I had removed and I am now running the Alde heater to fully circulate and hopefully mix the gallon of water that is now lost in the system someplace.  Trusting that it will not freeze and blow the whole system overnight.   I will resume this chore when I catch my breath. 

qhumberd

@Carsoncitysmith hopefully once you do this once it will get easier. It did for me.

A couple of points. Your photo of the air bleeder in a cabinet does not exist in my 2019.  The only bleeder is in the bathroom under two small Phillips screws (a little hard to get to unless you have a stubby driver). Here is a pic on the small cover removed (screws receiver areas on either end):



Now in my flush and fill I pulled the drain plug under the trailer and got about 1 gal, like you. My closet reservoir did not drain until I opened the bath bleeder above, and then the rest of the reservoir drained. At that point I removed the hoses to the reservoir as shown here and began to pump distilled water thru



This pic shows the distilled water going to the Alde on R and the first of the remaining glycol being pushed out on the L below:



It took 5 gallons of distilled water to get a true clear return from my system. Then I began to refill with new glycol. It took about 2.5 gal to start to see a color change from the distilled water back to the glycol color, and then I put another gal of fresh glycol thru to make sure, leaving a 1/2 gal to refill the reservoir and purge any remaining air from the loop. When purging you need to increase the pump or pumps to 5 and watch the reservoir and refill as it drops. On my second flush and refill it took very little extra, as I had not blown out or vacuumed the system, only drained and flushed.

I did open the bath valve after each time of running the pump on 5 to get the small amount of air which would rise to the point. Otherwise no problems either time.

NOTE: I am not sure if you have to do anything extra with the Flow pump or not. I did not on the first exchange, and then did on the second. You have to force the Flow pump on by setting the hot water setting on max. That turns on the Flow pump and I noted that the regular pump does not operate in this mode. Maybe that moves some glycol that might be trapped in the Flow unit? 

At any rate my system has worked well each time. If I were your I would flush the same way but between pump cycles after refilling I would briefly open each bleed valve you find to release any air until glycol flows. I am not sure if your additional bleeds would aid in draining, but at that stage of the process it would be worth a try as the bath bleed did help drain my reservoir and those related hoses.

Good luck after you get back to it. Just let us know what you learn and we can pass it on.

Carsoncitysmith

That procedure sounds good to me except that SCottG 's instructions are clear about taking the hoses and bleeder apart over by the Alde unit and then pressurizing some hose there to push the rest out.  

I think the pump by the Flow is meant to work while the general circulation pump is not working, to prioritize heating water over heating the convectors, when hotter water is required. 

I want to get 3 (+?) gallons of old yellow out and I seem be only be getting maybe 2 gallons out.  Maybe the 5 gallons of flush will find the missing gallon of old Yellow, but then if I don't get my five gallons of flush blackout that will mean I am leaving maybe a gallon or more of plain old water somewhere in the system, which is going to dilute the new Blue, the already diluted new Blue.  
 
Maybe I should just try that and be prepared to buy a 4th gallon of new Blue to add later?
How hard can it be?

Note: My reservoir is in an awkward place, upper front left corner of the trailer and I found it simple to detach the hoses from the bottom and to press in ¾" plugs for my pump and drain lines. 

P.

ScottG

@Carsoncitysmith, glad to see you are tackling this job with gusto, and that my DIY write-up was helpful. It's worth noting, however, that my method was based on a 2015 "320" with a much simpler glycol loop than a modern 400 with the Flow unit. I can't guarantee everything will work the same for you, but please keep plugging at it and report back on your results!

qhumberd

Carsoncitysmith said:

That procedure sounds good to me except that SCottG 's instructions are clear about taking the hoses and bleeder apart over by the Alde unit and then pressurizing some hose there to push the rest out.  

I think the pump by the Flow is meant to work while the general circulation pump is not working, to prioritize heating water over heating the convectors, when hotter water is required. 

I want to get 3 (+?) gallons of old yellow out and I seem be only be getting maybe 2 gallons out.  Maybe the 5 gallons of flush will find the missing gallon of old Yellow, but then if I don't get my five gallons of flush blackout that will mean I am leaving maybe a gallon or more of plain old water somewhere in the system, which is going to dilute the new Blue, the already diluted new Blue.  
 
Maybe I should just try that and be prepared to buy a 4th gallon of new Blue to add later?
How hard can it be?

Note: My reservoir is in an awkward place, upper front left corner of the trailer and I found it simple to detach the hoses from the bottom and to press in ¾" plugs for my pump and drain lines. 

P.

It certainly sounds like you have the right procedure going, but from what I understand you must be thorough in removing all the Century yellow fluid before adding the non compatible Rhomar blue. Some have even mentioned a cleaner before the new fluid. That would be a Truma call I suppose. 

At any rate if you can access the hoses from your reservoir then it seems you can pump as much distilled as you need to get a clear return. If you are pumping thru the loop, although it is longer than the 320, I cannot imagine that too much old fluid would be trapped. Another thing you might consider is to run the circulation pump when the system is full of distilled water to allow more time to fully dilute the loop. This of course takes more time.

BTW @ScottG and others might like know if you have noted any corrosion in the loop connectors that you have been able to inspect.

Carsoncitysmith

I found a video from Alde showing how to replace fluid,https://www.youtube.com/watch?v=2olLi_O8xXI.  
But this is replacement with like kind fluid, not the full purge and change to a different fluid. 

Their procedure is pull the drain plug, drain and replace, and then pump in new fluid discharging the old.
Their Alde pump doesn't look special in any way.

I just wrote Nucamp and was told that they will not share the instructions they give the Dealers with people who are just owners, but that I needed 4 gallons of the new stuff to complete the exchange.  I suspect that the extra gallon goes to expel the water remaining in the system when you have finished flushing out the old yellow fluid.

No, no sign of any corrosion/swelling around any pipe/hose fittings. 

P. 

qhumberd

4 gallons is what I used for my last flush and fill. I stayed with Century TF yellow as my system looked fine and I plan to replace the glycol every two years.

The pump in the video is I believe one that dealers use but it is seemingly more complex than the DIY methods in this thread.

Good luck!

Carsoncitysmith

OK, a week has passed with my trying to wrestle advice out of Nucamp.  They seem to think pumping flush water through until clear and then new Blue glycol and getting into the 4th gallon will do it.  I plan to run the circulation pumps, including the hotter water circuit by the Flow unit, when I am in the water flush process, because I don't understand the extent to which normal circulation will flush the Flow unit.  I might do that again when I think I have filled the circuit with the new blue stuff.   How much extra water might there be in the Flow loop to dilute my Blue glycol?
I bought a 4th gallon of Blue glycol. 
It is hard getting to and seeing the pump speed setting knob.
I need to time the chore to not risk having water in the circuit overnight.  It is freezing hard here at night.
I asked the "Customer Experience" guy who answered emails to Tech@Ncmp if I had to disconnect any hoses or relief valve around the Alde heater and he said "I don't think so" which is not reassuring.
Three requests to see the Service Bulletin they sent to dealers on the glycol replacement have been ignored.
I'm going to wing it.
P.

qhumberd

Carsoncitysmith said:

OK, a week has passed with my trying to wrestle advice out of Nucamp.  They seem to think pumping flush water through until clear and then new Blue glycol and getting into the 4th gallon will do it.  I plan to run the circulation pumps, including the hotter water circuit by the Flow unit, when I am in the water flush process, because I don't understand the extent to which normal circulation will flush the Flow unit.  I might do that again when I think I have filled the circuit with the new blue stuff.   How much extra water might there be in the Flow loop to dilute my Blue glycol?
I bought a 4th gallon of Blue glycol. 
It is hard getting to and seeing the pump speed setting knob.
I need to time the chore to not risk having water in the circuit overnight.  It is freezing hard here at night.
I asked the "Customer Experience" guy who answered emails to Tech@Ncmp if I had to disconnect any hoses or relief valve around the Alde heater and he said "I don't think so" which is not reassuring.
Three requests to see the Service Bulletin they sent to dealers on the glycol replacement have been ignored.
I'm going to wing it.
P.

It sounds like you have a solid plan. I too have had questions about the plumbing of glycol inside the Flow unit. I have never seen a diagram such as is available with the main Alde boiler. 

So if I were you and changing to the Rhomar it would be reasonable to flush the system with distilled water, and then while full of water, run the circulation pump followed by the Flow pump and then continue flushing. As I mentioned the 4 gal was the exact amount I needed and I have 1/2 gal left for topping off the reservoir. Of course I was not changing to a new glycol so I was not as concerned about some glycol being trapped in the Flow unit. But more time and more distilled water would be the only downside to the process.

Just so you know, based upon flushing to a clear water color I used 15 gals on my first exchange, so it can take a lot to not see color when your are flushing.

With all the uncertainty about the corrosion issue this far into the problem, and with my experience on my unit, I am deciding to stick with my yellow Century and just be diligent about regular changes every 2 years. Now that I have the setup and have done it twice, it really has not been too big of a chore. With all the variety of opinions floating around, I would likely never let a dealer mess with my unit. 

Robermcm

Regarding the flow plumbing and how much liquid is in the Flow,

I saw a cutaway of the flow tank at the Truma Elkhart service center. The glycol runs through the flow unit in a 3/4” coiled tube and back out. The majority of the space inside the Flow tank is water to be heated. 

So, I’d estimate that materially less than a quart of glycol would fill up the tubing from the boiler to the flow and back. Your point about running the pump to flush the flow tank is a good one. Per Truma, the Flow pump runs when hot water is ‘turned on’ for BOTH the 120 degree and 140 degree settings. 

Side note - the flow tank is thin stainless steel, wrapped in a thick styrofoam blanket. VERY easy to crack open if left over winter with much water in it. Compare that to the boiler, which is two pretty robust Russian doll style stainless tanks for water outside and glycol and heating components inside. Both can be destroyed with freezing water, but the Flow can’t handle even small errors. {Truma tech}

AnOldUR

Robermcm said:

... The glycol runs through the flow unit in a 3/4” coiled tube and back out. The majority of the space inside the Flow tank is water to be heated.

Someone correct me if I'm wrong, but my understanding is that the glycol is in a chamber, not a "3/4" coiled tube". I believe the tubing you see in this cutaway are the two electric heating elements that are sounded by the glycol inside that chamber. The outermost chamber is for domestic water, the center chamber has the electric elements and glycol and the inner chamber is where propane combustion takes place.

I am curious about how much glycol is in the chamber. Does anyone know?

Robermcm

someone asked how much glycol is in the flow unit. That’s what I was attempting to answer from my experience. The boiler is indeed an inner chamber of the boiler. 

Here the inner chamber, minus the propane flame chamber and electric heating loops. 

AnOldUR

Robermcm said:

The glycol runs through the flow unit in a 3/4” coiled tube and back out. The majority of the space inside the Flow tank is water to be heated.

Robermcm said:

Here the inner chamber, minus the propane flame chamber and electric heating loops.

This is somewhat confusing. Are you saying the glycol is in tubing or in the chamber and once the "flame chamber" is inserted into "inner chamber", what is the volume of glycol needed to fill it?


(the arrow is because this picture was hijacked from a cracked tank thread)

AnOldUR

If you trust AI, it looks like the Alde 3020 holds about a gallon of glycol by itself.

Bill&Suze

AnOldUR said:

Robermcm said:

The glycol runs through the flow unit in a 3/4” coiled tube and back out. The majority of the space inside the Flow tank is water to be heated.

Robermcm said:

Here the inner chamber, minus the propane flame chamber and electric heating loops.

This is somewhat confusing. Are you saying the glycol is in tubing or in the chamber and once the "flame chamber" is inserted into "inner chamber", what is the volume of glycol needed to fill it?


(the arrow is because this picture was hijacked from a cracked tank thread)

@AnOldUR, I think that @Robermcm stated what he physically saw at a Truma service center regarding the innards of the Flow unit. Sounds like there was a cutaway plainly showing a 3/4" tube inside it. My impression of the diagram you posted is that it's a cutaway of the Alde boiler innards. If there were a combustion chamber in the Flow, logically there would be an outside vent.

Robermcm

There are two thoughts being mixed here. The volume of glycol in an Alde boiler (eg, 3020) and the volume of glycol in the optional FLOW hot water heater. The 3/4” coiled pipe I mentioned is found full of glycol inside the Flow tank. 

AnOldUR

Bill&Suze said:

... Sounds like there was a cutaway plainly showing a 3/4" tube inside it ...

Yes, this was my mistake. I should have read and researched more carefully before getting involved. Our older T@B does not have the Flow unit and I'm not familiar with it. It sounds interesting, but I'm having trouble finding a cutaway picture or anything on how exactly the system works. Sorry for the confusion.

Carsoncitysmith

Thanks everyone for jumping in here and especially for the details on the Alde and Flow interiors.
I will work with the idea that there is up to a gallon of glycol in the Alde and the coiled pipeful in the Flow.  I am sure that the gallon in the Alde will explain the necessity for a lot of flushing.

 I see a reference to 15 gallons of flush water.  I bought 4 gallons of distilled, but I think I will use tap water to start and then flush the tap water out with distilled before I start flushing that out with the new blue Rhomar stuff.  <<$60/gal diluted plus shipping>>  Meanwhile it is really cold here even during the day and I am putting this chore off for a while.

Carsoncitysmith

OK, DONE.  Not gracefully, not without moments of hesitation, frustration and head scratching, but done.  It took about 2 hours, 3? gallons of yellow out, 8 gallons of tap water flushed through until it was clean to the eye and taste, 3 gallons of distilled water through, pushing out a presumed three gallons of tap water. 
Then 2.5 gallons of new blue fluid in until the discharge starts appearing blueish,  then finish the 3 gallons of blue fluid and maybe 1 quart from the 4th gallon so that the discharging blue fluid is as blue and the fresh stuff by eye. 

An additional 2 <#######delete bad language#####> hours getting the hose placed on the bottom of the reservoir with a secure clamp in an awkward cubby hole, head, shoulder, arm, pliers, flashlight, reading glasses, over and over and over again last night and this morning. 

Then decide that the tiny red adjustment on the pumps set the speed and that turning them clockwise gives you the high speed setting.  Then decide that you can't run Cont pump and hot water heater at the same time, set the pump to Therm and turn off the water heating function to get the pump working.
I wanted to also get the second pump, the extra hot water Flow pump running, to be sure of circulation through the Flow, but I think that is accomplished without the booster pump, because the glycol outlet from the Alde runs directly into the Flow and through a coiled tube in the Flow.   As compared to the heater in the Alde unit where the glycol enters into a bath, so blowing air into the resident fluid just bubbles up and out rather than pushing the glycol out.  Note: My Alde Manual says that there is 0.9 gallons of fluid in the Alde if I am reading it correctly.

I used a cheap hand pump from Harbor Freight, $14? ,and it worked fine. 
3/4ths of a gallon of blue fluid left over.
Now wait and see if there are any reports on how often I will be expected to repeat this process. I think the theory is that blue fluid is better than yellow fluid, so we should be able to change it less often. 

Note, this is a 2021 400, the last week of production with yellow fluid.  Note that I removed the hoses from the bottom of the reservoir and inserted ¾" plugs for input and output lines.  If I live so long, next time I may detach the reservoir from the wall and insert hard pipe and plugs into the bottom of the reservoir, to avoid the <###> hose clamp problem.

Note: the Alde Manual says to not mix different glycols for fear of coagulation.  I may test mix some to see. 

Note: Both the blue and the yellow glycol claim to be non toxic.  I have two gallons of near full strength and maybe 8 gallons of diluted yellow glycol that I would like to pour down the toilet rather than drive to the city dump and pay money for some ding dong to tell me it is hazardous waste. 

The heater is running nicely.  I didn't have to top off the reservoir.  

Thank you my moral and technical support network for your advice along the way.  Good luck to the next guy. 

P. Smith

Carsoncitysmith

As I was typing the above the Alde and pumps were running and the fluid reservoir dropped a couple inches, so I brought that back up to level.  There must have been a bubble in there someplace.

qhumberd

Nice work and your diligence paid off. Glad your system is working well!

BTW the exchange interval recommended is 2 yrs for the new and old glycols if my memory serves 

Happy New Year

Krampatt

Maxcamp said:

@ScottG et al, appreciate greatly the shared instructions and experiences.

Just did the two year interval Rhomar in-kind swap today on our Jan.2021 320s.
 Handpump method (harbour  freight cheapie), two copper tubes with bungs plugged into reservoir outlets. 

Necessary to invert pump or pumping tons of air.
 10 to 12 turns of Teflon tape over 3/8 soft copper tubing to get the amazon bungs to hold tight.  Was concerned they might stay behind in reservoir upon withdrawal of tubing system.  Hose clamps as stops to keep bungs from sliding up when seating.  

Tried pumping into reservoir port leading to alde pump but 100% resistance and no flow back from reservoir radiator port. 

Re-read Scott PDF narrative, flip flopped pumping port selection and quick success.  
Very clean waste coming out

Another surprise, the alde circulation pump was on lowest setting,  had never heard it run.  We had poor heating performance with superheated rear bed area.
Bumped up to 5 for air bleeding via reservoir and then set to middle at 3.  Now can track its use audibly.  

2 gallons left in 5 gal pail purchased on account from my hvac supplier for 189.
2 inch lid screwport means did not open pail lid.  Will it keep another two years?

Was there any risk of the stopper staying at the bottom of the tank when you pulled them out? That's a legit concern it seems.

DM159

Just returned from TRUMA in Elkhart, IN for our 2 year anniversary after having the original ALDE boiler replaced at NuCamp (potential error in robotic welding the interior tank together).  New glycol pumped in and we are good for another 2 years.  The guys at TRUMA were quick and knowledgeable about the ALDE system in our 2022 TAB400.  Their process is to "siphon" (with vacuum) out the old glycol at the reservoir tank and use an air pressure assist at the glycol drain valve.  The new glycol was poured in the tank and the vacuum was applied to the drain valve to pull it through the system. I wish I could have observed the guys at work but we were asked to hang out in the waiting room.  The process in not cheap.  But it is quick and done right by their standards.  We are looking forward to another 2 years of trouble free heating.  One point the techs mentioned was to do the initial ALDE heating with propane and then switch to shore power after the ALDE is up to temp.  (Providing that shore power is available at your campsite).     

Robermcm

I had the same experience when they replaced my boiler (broken from freezing with water in it).  I wanted to hang out with them, but they only let me in the trailer a few times. Got to see their Alde glycol cart with the pumps and fluid. Should have taken more pictures!  Super nice guys too. 

Citruscountytab400

As long as you test the ph and freezing  point of the fluid each year, you may never need to change it.  I'm going on 6 years and it ph tests at 9/10 (new tests at 9/10 also) and the freezing point hasn't changed, either.  I full time RV and check all hoses and connections yearly, with no corrosion or leaks.  NO antifreeze goes bad every two years, and besides for adding a qt every year due to evaporation, everything runs and looks perfect. Just like with a vehicle, you do more damage to it not using it and letting it sit.  Keep the appliances going all year, and you won't have half as many issues as if it is only used 30 days a year.  

Robermcm

I spoke with a Truma tech about the Alde fluid, back when I had the boiler replaced. Was asking about the 3020 and how it operated, with flow direction and one-way valves/pumps. She was helpful and acknowledged that the new fluid - was rhomar brand, probably didn’t need replacing as frequently as the older fluids (more anti corrosion chemicals), but that Alde was reluctant to specify a longer flush period due to all the changes in glycol formula and varying ways people treated their systems. Made sense to me. 

pthomas745

The glycol, the ph balance, the change cycle, etc, has always been the red herring on the mystery of the corrosion of the Alde convectors on the Alde 3010 trailers. During these long winter nights as I read and reread the long threads about the issue here, you will find many references to the PH of the glycol....and all of them mention how rock steady the ph balance of any of the glycol samples taken.  Tons of threads mention the ph of the glycol.

https://www.google.com/search?q=glycol+ph+site:tab-rv.vanillacommunity.com&amp;client=firefox-b-1-d&amp;sca_esv=14fece966019238c&amp;sxsrf=AHTn8zq27yYFcoTRsCJxGXplvW3J28mA8Q:1739464351690&amp;ei=nx6uZ5zqKYfUkPIP4-eXEA&amp;ved=0ahUKEwjctaDWicGLAxUHKkQIHePzBQIQ4dUDCBE&amp;uact=5&amp;oq=glycol+ph+site:tab-rv.vanillacommunity.com&amp;gs_lp=Egxnd3Mtd2l6LXNlcnAiKmdseWNvbCBwaCBzaXRlOnRhYi1ydi52YW5pbGxhY29tbXVuaXR5LmNvbUjGLlDJCVjQJ3ABeACQAQCYAUWgAa8IqgECMjW4AQPIAQD4AQGYAgCgAgCYAwCIBgGSBwCgB-UI&amp;sclient=gws-wiz-serp

I'm not sure if the groups have seen any corrosion of stub ends in trailers built roughly after 2020.  If you compare the construction of the Alde hoses and hose routings  and basic design my 2017 and a 2022, for example, the construction is night and day.  The glycol was never the problem, it seems, but construction practices were.  It will be interesting in a year or so, when owners of Alde 3010 trailers who cleaned their convectors, coated their stub ends, clamped the hoses correctly, and simply stayed with the Century brand glycol encounter any corrosion at all.

Carsoncitysmith

Right.  Having just changed over to the new blue stuff I would really like to NOT do that every 2 years.  I will watch my fittings and this discussion page looking for any reports of corrosion over the coming years and keep this in mind.  Also I will look for some explanation about what pH has to do with corrosion protection.
Happy Trails you all.

manyman297

This coming summer marks another 2-year Rhomar change and I’m seriously considering skipping it. Like @Citruscountytab400 said, glycol shouldn’t go bad in two years but Alde has put the fear of god in us thinking it will explode if we don’t.

I’m thinking of maybe just doing a visual check of the convector connections and check for bulging and call it good this year. The process for the exchange isn’t particularly difficult but the expense is such a deterrent for me and I could never source the cheap Rhomar because I’m not an HVAC contractor and couldn’t find a supplier. 

We’re on year 4 now with the new Rhomar glycol in these Tabs. I wonder how many people have actually kept with the 2-year schedule?

Maple_Geek

I have a 2022 TAB 320 BD and I have not yet changed the Rhomar glycol. I will inspect all the fittings when it gets out of storage again this year. I'm taking the risk and plan to consider doing it every 5 years but I'm also looking at these posts and will change my plan based on evidence.