Switching to New Rhomar Glycol

stepheng

I'm getting ready to do this and will switch to the new glycol.  Has anyone documented a complete procedure on this - i.e

1. drain old fluid
2. water flush
3. hydro-solv 9100 cleaning (including how long to circulate in system)
4. second water flush to neutral pH
5. new glycol fill

If not I'll do it when I do mine. 

Anyone have a source for the Hydro-solv 9100?  Found one place $65 for a gallon - makes 50 gallons.

pthomas745

This thread has been running for 5 years, and there are several methods of doing what you are proposing.  Someone may point to the specific procedures (it is in there somewhere!).  Start at the last page and just page back for a bit.

https://tab-rv.vanillacommunity.com/discussion/2665/changing-out-the-alde-fluid#latest

And, of course I found what I was looking for as soon as I typed that answer above.  The DIY exchange thread here:

https://tab-rv.vanillacommunity.com/discussion/comment/166510/#Comment_166510

stepheng

@pthomas745 Thanks for the link.

FYI I was able to get the new glycol here in Phoenix at the Tom's Camperland in Mesa.  $36/gal.

stepheng

Just want to confirm which hoses that connect to the reservoir are the input and output.  Deep hole is output?

Denny16

The input line connects to the last convector in the loop and the output side (normally a larger diameter hose) connects to the Alde boiler.
 Cheers 

ScottG

stepheng said:

Just want to confirm which hoses that connect to the reservoir are the input and output.  Deep hole is output?

@stepheng, Illustration 1 in this document shows the flow of glycol through the expansion reservoir. The deep hole directly below the cap is where glycol returns to the reservoir after passing through the convector loop. The offset hole that is flush with the bottom of the tank is where glycol leaves the reservoir to return to the Alde boiler. In my case, the associated hose are the same size on both connections.

In the document I do refer to the deep hole as the "outlet" and the offset hole as the "inlet" but those terms can be potentially confusing depending on how you visualize the flow of glycol through the system.   

[Deleted User]

Stepheng, I just wanted to make sure you are aware that you have to have a special pump to get the glycol out.  You can only get about half of the fluid out without the very specialized pump.  

stepheng

@TabbyShack Thanks for the reminder. Mine is a 320.
I just finished the changeout to the new Rhomar fluid. I did use drain/vacuum to get the existing fluid out and then ran 15 gallons of distilled water through the system. Then I had to drain out the water with a combination of the gravity drain and the vacuum. Once all the water was out I pumped a little over 3 gallons of Rhomar into the system wasting about a half gallon just to make sure to flush out ant remaining traces of the water. Filled the reservoir then ran the recirc pump at 5 for 10 minutes or so and then set back to 2. Then topped off the reservoir. Tested the heat this morning - needed to do it early before it gets to 70+ here in Phoenix.  Works fine now.  Will add ground wire to Alde later today.

Basil48192

I've seen a 'relatively' easy procedure on YouTube.  They used an inexpensive submersible pump which they dropped into a large bucket of new fluid.  After draining out as much of the old fluid as possible, they disconnected both supply and return lines from the bottom of the expansion tank.  Then, with short sections of garden hose, they connected the supply pipe to output of the pump and the return pipe to a waste bucket.  Then they just ran the pump until there was a steady, 'un-mixed' flow of new fluid coming out of the waste hose.  The hoses were then re-connected and the air bled out.  
It seemed pretty easy, however, I would flush the system with distilled water before pumping the new fluid through.  I'm just not sure if I can get to the bottom of the reservoir very easily in my 2021 T@B 320S.  It is mounted in the enclosure under the bathroom sink so it might be a bit difficult.  

Denny16

Doesn’t your 2021 have the dual Alde drain lines coming out the back?  If,so, you,can attach the pump in line here, and use one connection for drain and the second to pump fluid in.
 Cheers 

bergger

Our 2021 400 only has the single Alde drain line.  I think they went to the dual external lines, one drain line one fill line, on the 2022 models. 

bergger

@stepheng did you use a hand pump or a 12v pump to pump in the distilled water and the rhomar fluid?  I plan on switching out our 2 year old TF-1 fluid with Rhomar this spring.  I plan using the drain/vacuum method to remove the old then pump 15-20 gallons of distilled water through the system.  I'm just debating on using a manual pump or trying to us a simple 12v pump as used in the recent youtube video Basil48192 referenced.

stepheng

@bergger I made the adapters in the procedure @ScottG provided above and placed them in the reservoir. Removing the reservoir and connecting directly to the hoses is no simple task. Also remember to unplug the 120V Alde cord to prevent the heating element from coming on while the system is empty. You can turn the system on and run the recirc pump with only 12V to the system.

I connected the "return" adapter tube to a shop vac and removed the old fluid.  It took quite a while as when it looked like it had finished another burst of fluid came through the line. when it finally looked like no more fluid was being sucked out, I put the "input" adapter tube in a clean 5 gallon bucket with distilled water. It began to draw the clean water into the system and I kept filling the bucket with more water until I had run 15 gallons of distilled water through the system.  I also ran the Alde recirc pump a couple of times to help the flow .

After that I kept the vacuum running to remove the water.  Again it took a while.  I also opened the drain under the trailer, got a little more out.  With the drain open, I raised and lowered the trailer a few times and even more came out.

Once I thought I had all the distilled water removed I connected a hand pump to the "input" adapter tube and placed the "output" tube in another 5 gallon bucket.  I began to pump the new Rhomar fluid into the system.  It went much faster than I expected and after 2 - 2 1/2 gallons it began to flow out of the "output" tube into the bucket.  I continued to pump until I had used 3 gallons of the new fluid.  I then removed the adapters from the reservoir and filled the reservoir to the "max" line.

I then ran the recirc pump at "5" for 10 minutes or so and then set back to "2." Then topped off the reservoir and reinstalled the cap.

I then plugged the 120V Alde cord back into the outlet and turned the system on.  I set the temperature up and let it run for about 30 minutes and checked the radiators.  Warm, but not hot - turns out I had the electrical setting on the Alde at "1" - I changed it to "2" and checked it about an hour later and it was heating fine.

It seemed to gurgle more at first, but settled down after a few hours of running - probably a little remaining air getting bled off.

It took longer than I expected to remove the old fluid and flush the system.  If I had to do it again I think I would use the gravity drain and remove what I could, replace the drain plug and then use the submersible pump (or even the hand pump) to flush the system with distilled water.  Might use a little more since this would be pushing out the old fluid at the beginning.  I'd still try to get as much water out as possible before filling with the new fluid to prevent any dilution.  You could always run a gallon or two of extra Rhomar through to be safe, but that's an expensive option.  I wasted about a 1/2 gallon.

Let me know if you have any questions.

Tabulating

Hello,

I bought some Rhomar Water and I plan to do the fluid swap-out myself.  I think there is enough info here to do as good of a job as any shop.

But here is my REAL question:  Airstream is shipping grounding wire kits and the new antifreeze as part of their recall.  These parts are tied to the VIN of each camper.

I haven't seen any mention of grounding kits anywhere in these threads or heard anything about adding some grounding to the NuCamp Alde heaters.

My understanding is that there are some galvanic reactions occuring, (a few owners have reported bulging hoses at the convector connections).  I get that a thorough flushing and replacement of the fluid is required.  However, is this all for naught if we don't properly ground our systems.  Are we possibly overlooking the most important piece of info to be gleaned from the Airstream recall?  Should we be running aluminum wires from each convector back to the Alde or do we need to just ground Alde heater?  Or is the grounding part of the Airstream recall not pertinant to T@bs for some reason?

Or do we truly just need to replace the fluid?  Anyone have any info or thoughts?

Thanks,

Bill

Dutch061

Bill,

I too am going to swap to the new "Rhomar Water", my $12.00 submersible pump should arrive today from Amazon. I have read the Airstream bulletin about grounds etc. and part of what Airstream is doing is replacing the ground wire from the power distribution center to the batteries with a 6-gauge wire (replacing the previous 8-gauge).

Since my converter is located within a few inches of the batteries (I removed the WFCO and replaced with a PD9160ALV), I am not so concerned about the gauge of wire in between the Power Distribution Center and the Batteries. However, I will be doing a voltage drop test between the Ground Bus Bar, the Frame, the Alde, the Converter, and the Batteries. I want to make sure that everything has the same ground potential. Once I have tested this, I will have a better idea of my next step(s) that will need to be taken. 

If the Alde is grounded to the rest of the system, there is no need to ground each convector. Grounding the Alde will remove the voltage potential and the associated galvanic potential that occurs. 

Brad

ScottG

There have been several deep discussions about both corrosion of the convectors and the whole Alde grounding issue. While there are some odd voltage potentials involving the Alde cabinet, I'm not fully convinced that the corrosion of the convectors is galvanic in nature. However, clear, authoritative information on these subjects has been in short supply.

Dutch061

Okay, a quick update to the process that I used.

First, the things that I bought specifically to do this work.

Submersible pump from Amazon $12.00
20 Ft 1/2" PVC tubing from Lowe's $10.00
5 Gallons of Distilled water $5.00
4 Gallons of Rhomar water $$144.00 ($36.00 per gallon from my dealer)

Process

I cut the 1/2" PVC tubing into 2 lengths of 10 ft each
I attached 1 piece to my 25-year-old shop vac
I attached the other to the pump

Using a pail, I poured 4 gallons of distilled water in, and dropped the pump in the pail.
The other 1/2" PVC attached to the vacuum cleaner was inserted into the return well in the tank, which is the one with the recess (or straight down from the fill cap).

I started the vacuum cleaner, turned the Alde on (no heat of course) and then used the pump to keep water in the reservoir to prevent introducing air into the system. I used 5 gallons of water total to flush out the century fluid. Put Rhomar water in the pail instead of water, dumped the vacuum cleaner and started the process a second time to replace the distilled water with Rhomar water.

Total time was less than 20 minutes start to finish. My wife did assist me with the operation of switches. 

Done the voltage drop tests noted above on the grounds, added a ground wire to the Alde unit to reduce the voltage drop to less than .002 volts. It was nearly .040 volts before. 

Brad

bergger

I plan on flushing my system and filling it with Rhomar this spring and your method seems super simple.  So did you just shove the pvc tubing from the vac into the reservoir tank return side without using any fancy plumping pipes or fittings?   And just drop the hose that introduced the distilled water into the system into the reservoir tank as well? 

Basically you were just pouring water into the reservoir tank which was then being pulled into the system by the Alde pump and then removing the glycol as the water was pushing it out and the vacuum was also sucking it out as it came back into the reservoir.  After you began to suck water into the vac then you stopped and replaced the distilled water with the new Rhomar fluid and introduced that until you saw it come back into the shop vac side.  That's what is sounds like but I just wanted to make sure I'm clear on your procedure. 

Dutch061

@bergger, yes, I stuck the PVC tubing into the inside of the return nipple in the tank. Then I used the other line from my submersible pump to keep the reservoir full, turned the Alde pump on (I never changed the settings) and ran the vacuum cleaner at the same time.

Some would wonder if this really worked or if I mixed fluid etc. I ran 5 gallons of distilled water through, and it was nothing but water coming out. Likewise, when I started to push Rhomar water into the reservoir, there was nothing but Rhomar coming out after a little over 3 gallons. I kept back about 1/2 gallon of my 4 gallons in case I need to add some.

As far as using a chemical to flush, as per the Airstream bulletin they use "clean tap water"; I just read it again, so I could have used tap water but this way I can say I pampered it by using distilled water. 

Cross contamination

I am not concerned as they are both Propylene Glycol based and if there is some residue of the Century Fluid, it won't hurt anything anyway.

Funny story about cross contamination

In the early 90's when the automotive industry switched from R-12 refrigerant to HFC-134A, they recommended that for all retrofits the hoses be replaced, the compressor removed, dumped then flushed, and then flush the evaporator and the condenser. Then add the required amount of PAG oil, evacuate and recharge the system. The claim was even 1 drop of mineral oil that was used for lubrication in R-12 systems would cause the PAG oil (Polyalkylene Glycol) to clump up causing complete failure of the air conditioning system. As years went by, I watched people take an R-12 system, purge it and evacuate and recharge with HFC-134A. They didn't even add PAG oil. Never saw a failure. 

Not so funny

Some used propane for refrigerant, after all it has very similar temperature-pressure properties as R-12. However, as everyone knows it is quite flammable too. Sadly, there were people who were injured and burned becuase of this.

Brad

Tabulating

I have read a few comments mentioning how hard the heating connection clamps are to remove.  I bought these and they make removing the clamps easy. 

Knipex Spring Hose Clamp Pliers With retainer

It has pivoting crowns designed to engage the tabs on the clamp AND the lock automatically once you have the clamp expanded enough to undo the fitting.  I have an '18 400 that did not have the Alde Flow box, so I added it.  This pliers made removing and then reinstalling the clamps trivial.

They are $60 to $100 depending upon where you buy them, but a good tool is a joy forever and they made working on the Alde much more joyful.  Having used them, I wouldn't want work on the Tab heating without them.

Bill



I

bergger

@Dutch061 thanks for the response.  I'll probably go ahead this Spring and use your method.  It seems simple and effective.  I know you did not change the setting on your Alde pump but do you happen to know what setting it is on?  I believe mine is at 2.5.  Also what submersible pump did you buy from amazon?  

Dutch061

I used this pump

https://www.amazon.com/gp/product/B08516QWPZ/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

We carry a 5-gallon water bottle to add water while boondocking, so I will use this pump to put the water in the tank instead of pouring it from the bottle through a funnel. Make life a bit easier for that too. 

I have both of my pumps set to 3.

Brad

P.S. I was going to remove the tank and use connectors to hook up my hoses and decided there was too much chance to fracture the fitting on the tank or otherwise just too much messing around. I even bought a set of hose hooks to facilitate removal of the tank. I try to use the KISS method in most of my endeavors.

N7SHG_Ham

@Dutch061, not so sure on the cross contamination, both Alde USA and NuCamp seem to indicate that it is extremely important to make sure you do NOT cross contaminate as they are incompatible even though the base fluid is of course propylene glycol.

The shop that I have scheduled my change with also indicates it is important.

It might be marketing or CYA talk, but until proven otherwise, I am going with it is critical to not contaminate the new fluid with ANY of the old.

Dutch061

@N7SHG_Ham, yeah I am not so worried about it based on a couple of things.

1. That they are both Propylene Glycol based as mentioned earlier and water soluble, which means that tap water is a suitable solvent 
2. The Official Airstream bulletin states to use "clean tap water" and not any kind of cleaning agent
3. Alde "recommends" using their pump kit, it doesn't say it is required. Although it would make it easier for a single person to do the job

In addition, when you look at the adapter that is illustrated in the Airstream bulletin and it's pretty much a guarantee that they don't seal 100%.

I'm sure you have seen it, but I am attaching it in case you hadn't. I may have mislabeled it as a "recall bulletin" when I saved it. 

In the end, the only way to completely remove 100% of the century transfer fluid would be to replace all the rubber hoses, fittings, and pumps, then thoroughly flush the convectors and the Alde boiler. I can assure you that no one is going to do that, even those of us who are OCD and perfectionists. 

Brad

bergger

As Dutch061 mentioned there is no way to completely remove all the century fluid unless the system is dismantled. I’m sure there will be small amounts left where the hoses seal to the radiators and in some other nooks and crannies. This will be the case whether you use the proprietary pump at the dealer or your own pump at home. The important thing is to get as much of it  out as possible hence the long water flush.  I’ll probably use 10-12 gallons of distilled water when I flush mine.  I’ll probably also push a bit more Rhomar through the system to hopefully get as much water out as possible. For me the biggest concern is to get out as much water as possible after the flush to prevent diluting the Rhomar. That’s why I’ll also either push some extra Rhomar through the system or drain and vac the water out then introduce the Rhomar. But I also like the idea of not putting air into the system as Ditch061 did.  So I’m not sure yet on that part. I suppose as the Rhomar level drops slowly over time, due to the water portion evaporating and you top off the reservoir with more Rhomar, as done with the century fluid, any small dilution during the switch over is probably a mute point anyway. 

bergger

So I just read the Airstream TSB on this matter and think I will go with Dutch061 method.  Airstream does no draining of the old fluid first, then flushing with water, then draining of the water before introducing the new Rhomar.  They push out the Century fluid with "clean tap water" 5-10 gallons, then push in Rhomar to push out the water.  This seems easier and as Dutch061 mentioned will introduce no or at least less air into the system.  

Denny16

This is how I understand the nüCamp Alde glycol pump system works, it pumps in the flushing water and pumps in the new glycol.  This is why it takes more glycol to fill after flushing a system, as it has to push out the water first.
 Cheers 

bergger

@Dutch061 so probably a dumb question, but how did you effectively connect the 1"2 pvc line to your shop vac?  Did you use a reducer of some sort to get an airtight seal?  I'm starting to put together my list of things to get for the project.  

Dutch061

To make the connection of the PVC tubing, I used 200 MPH racing tape. Yep, double sticky Gorilla tape and it worked fine.

Brad

Slackers

I can see 200 MPH RT working.  But what color?