Changing out the Alde fluid.

pak

Dalehelman said:

@pak
What model and year is your Tab? How many connectors?

I have a 2017 CS-S. There are 9 connectors that I can see. Im 100 miles North of Spokane. I think we are in the same general part of the world.

Dalehelman

@pak
sorry auto correction. I meant how many heat convectors or radiators.
yes Liberty Lake 

pak

Dalehelman said:

@pak
sorry auto correction. I meant how many heat convectors or radiators. 

There are 2-42" and 2-15"

Dalehelman

@pak
We have a 2015 Sofitel our expansion tank is in the rear. Am I correct the CS tank is in the front in the bathroom?

pak

Yes, in the wall behind the toilet. Changing the tank, if and when, will be scary

Dalehelman

@pak
That probably explains why I only had 6 1/2 qtsz shorter hose run. Thanks

RCB

Successful fluid change. I used The Scotty method. Drained +/- 1 1/2 gal from below, then pumped 4 gal of Century in as the existing 4 came out. Pretty much easy peasy. The only changes to the procedure I made were: 1. Used 3/8 soft copper tube ( bought by the foot at the hardware store) and 2. Attached a length of copper tube to the end of the suction side to prevent the vinyl tube curling and preventing emptying the gallon container of Century.
Otherwise the process is straight forward and without creating a mess. Thanks Scott.
So in a couple of years if I do change to the new juice, I am prepared !
Ciao, Richard

ScottG

Glad to hear of more successful glycol exchanges!

@pak, I take it from past comments you used the "gregndeb" adapters to fill from the top of the expansion tank. Did getting the adapters in the tank offer any challenge given the tight fit? I think you are the first to report doing this with a CS-S.

@RCB, great idea going with standard soft copper tubing. I think that is all those toilet lines are, plus a pretty chrome coating. I suspect the copper tubing is even easier to come by and one could probably get the store to cut the exact length needed, eliminating one more step from the adapter assembly process. I also like the idea of adding a length of copper to the pump inlet--I think I will make that mod to my setup next time around. 

ScottG

Dalehelman said:

@pak
That probably explains why I only had 6 1/2 qtsz shorter hose run. Thanks

I have the same configuration as @Dalehelman, and 6-1/2 quarts was just about what I got between gravity draining and blowing out the convector loop.

I know from my flushing with distilled water a little glycol was still trapped in the boiler core, but I don't have a good sense of exactly how much. 

BrianZ

For anyone using one of the two inexpensive pumps that have been successfully used to flush the Alde glycol (i.e., the manual pump, and the 12V electric pump), I have tested both for simply pumping water from a lower to a higher container, just to see how they work, and I have an observation to offer..

Both of these act like a siphon when you stop pumping, such that when the source container is lower and the entire line is still filled, the fluid will begin to flow backwards, returning to the source container.  Just turning off the electric pump or stopping manual pumping does not stop this flow. This could also be either an advantage or disadvantage with the source container higher (i.e., no pumping required, but no quick/convenient way to stop the siphon flow).  Just something to be aware of.

If the highest levels of the source & destination containers are similar heights, this may not be an issue.  For my use, I will have an inline on/off valve, or you can add one to your pump output line if you need to pause, just in case, as you may not even notice when backflow is happening when you stop pumping.  A check valve might help, but would only work in one direction.

Also, I previously tested air pressure and found that 15psi moved a gallon of water 3 ft higher in about 30 seconds (2 gal/min).  I later ran the same test with the electric pump and it took 48 secs, so it pumps about a gallon per minute.

ChanW

Ha! Hey Brian. Good 'adjustment'!

Please, feel free - post it. That 'drawing' is "public domain", AFAIC! These ideas are put out there to improve upon.

No, no 'scale' reality to the actual elevations, just somewhat relative, to give me an idea of why the high points are so difficult to evacuate by gravity and tilting. The tank ought to be lower in the drawing, methinks.

The '2-convector' Tab should be easier to gravity drain than the three, but obviously not completely. Good idea with the transparent hose. I was afraid of that being the case.

Nope - no copyright... (thanks!)

BrianZ said:

Hey ChanW, I took the liberty of editing your elevations drawing to fit our 2-convector Tab (per Scott's suggestion), plus added a few important features.  See what you think, and post it if you like.
-Brian
PS:  Are the elevations of each line or component meant to be in actual relative measured heights, or just in a "higher/lower than" general sense?  Either way, still very useful in trying to anticipate & understand how the glycol flows (or not). 
It's interesting to take a 3/4" transparent hose and make some up & down loops like a roller coaster, then pour water in one end & see what happens.  Even with a solid column of water going in, you still end up with pockets of air in the high points.  This drawing of yours helps.  Thanks.

Sharon_is_SAM

Is there a CSS version of this?  

ScottG

Did the last of the springerizing this weekend and fired up the Alde heat for another test. Third time's a charm--no sign of any more bubbles or gurgling in the expansion tank.

Even though I drained my system completely and introduced a fair amount of air when refilling, the circulator pump, expansion tank, and (maybe) auto air bleeder seem more than up to the task of getting rid of it. 

RCB

Scott, getting the tubes/stoppers into the tank was straight forward, however,  I should re-bend the copper tube for the offset one as the bend was right at the top of the tank. I held the tubes vertical with a couple of spring type clamps. The tubes were draped over the clothes rod (400) so the right angled bend at the upper end of the copper is not necessary. I shortened the plywood panel and plastic Alde cover to improve future access for topping up.

bergger

Though I'm about 1 year out or slightly less from having to change out my glycol I have been trying to follow this thread the best I can with my limited engineering mind!  I have come to the conclusion that I want to learn how to do this as I just don't trust the RV service shops in my area.  I have a few questions about your glycol exchange directions ScottG .  In step 9 you mention to make sure the gas burners and electrical heaters are off prior to turning on the circulation pump to get the air out.  With the Alde unplugged I assume the circulation pumps must run off of 12v?  Also if the system is now full of new glycol why is it so important to make sure the burners and heating elements are turned off?  Final question, for now!  I looked at my circulation pumps the other day for the first time.  The pump on the 3020 unit was set at 4 and the pump on the flow unit was set at 3.  This is how they came from the factory.  What is the normal setting for the pumps? The system has been working fine but these settings seem high as others have mentioned them being at 1.5-2.5.  

ScottG

I'm happy you want to tackle this relatively easy task yourself, @bergger --no shop is going to care as much for your T@B as you do.  ;-)

Ensuring the heat is off is just a precaution in the event that the boiler for some reason (like a big air pocket) is not completely filled. The electrical elements in particular can be damaged if they are operated without being submerged in fluid. The heat sources can be controlled at the panel, but the recommendation to unplug the Alde is just extra insurance, as there is no way the electric elements can be on without 120V AC power.

And yes, the circulation pumps will run on 12V, either from the converter (if the T@B is hooked to shore power) or the battery.

I'm not sure what the "normal" settings for the circulator pump speeds might be. In my simple 320 I find "1" (maybe just a smidge above) to be more than adequate to move fluid through the system and keep the sloshing in the expansion tank to a minimum. I imagine the ideal speed would be one that maximizes heat exchange efficiency between the boiler and the convectors, but trying to calculate all that makes my eyes glaze over, so I just go with the lowest speed that gets everything warm.

Thanks for your questions--they help improve the process and give insight into other models and configurations. I'm particularly interested in hearing your experience as you have the Flow unit. While I don't think that will make any difference in the general process, the return from the Flow might need a little special attention to ensure any trapped air is forced out.  

ScottG

@RCB, thanks for the additional input--sounds like you did a good job optimizing the process for your 400. Following up on my response above to bergger, do you have the Flow unit? If so, were you aware of any additional challenges to getting the air completely bled?

BrianZ

Forgot to post this revised drawing by @ChanW.
Resizing to 800 doesn't help the fine print, but I sharpened it a bit.  If you want a pdf version, I can send you one.
One thing that doesn't match our T@B, which I only recently discovered while disconnecting convectors..
The line from the top rear convector (with the bleeder valve) goes to our lower side convector, not the upper one as shown; but then it's just a schematic with 2 convectors depicted as one, so not necessarily "wrong" either.
PS: I just discovered that Chan's post above has a higher resolution version, so just get that. 

Tabaz

Just finished my fluid changeover using Scott's PDF instruction sheet.  Success!  Learned a few things about the Alde in the process: (1) the auto bleed works like a charm - no need to manually do anything, (2) If not needing shore power, then the Alde can be unplugged from the 110V outlet, (3) refilling with the new fluid only takes about 40 minutes using a funnel in the expansion tank.  Thanks so much Scott.  We now have a fairly simple way to change our Alde fluids every two years with relative ease.

BrianZ

That's great, @Tabaz!  So you didn't check for corrosion?  When did you last change glycol?
I'm now wondering..  If the auto air bleeder does it all, then what is the little manual screw bleeder for at the upper left of the rear convector?  That is a high spot that could trap air, so I'm wondering if running the pump at high speed would clear that out or not?.
I had already started reassembling ours after fixing up all the convectors when I realized I never took that bleeder elbow out.  Now have done that (with difficulty) & cleaned it up & coated the entire outside of both aluminum connector tubes with conformal coating, so they are nice & clean & smooth now.  Thinking I might skip the heat shrink tubing, since they are hard enough to connect already in that tight space.  I had to pull that tube into the storage space to disconnect it, so no fun trying to climb over the seat to get down into that corner.  This has been one of the longest projects yet for me, but fortunately I kind of enjoy the challenge of it.

ScottG

@Tabaz, congrats on getting the glycol changed.

Can you (or others who have done this) elaborate a bit more on your experience refilling the empty system by just pouring glycol into the expansion tank?  Did the glycol mostly trickle in and fill the system with gravity, or did it need to be coaxed in by cycling  the circulator pump?

I'm not convinced this is easier than pumping the fluid in with the adapters (which took me only about five minutes with an empty system), but I can see the advantage for someone who just doesn't want to deal with acquiring or making any additional tools (pumps, adapters, etc.).

Draining, blowing, or vacuuming out the old glycol and then refilling in this manner would be a reasonable alternative for getting the job done.   

ScottG

@BrianZ, given my experience, I'm not clear of the need for the manual bleed screw either. I suppose as another system high spot that area could trap air under some circumstances. The Alde operating manual also suggests it is not necessary, but goes on to describe a manual bleeding process that can be employed in cases of a "persistent" air lock.

Also, my convectors are connected as shown in @ChanW's diagram. I'm not sure why yours is different, but practically speaking I doubt it makes any difference in the operation of the system. 

qhumberd

.ScottG said:

@BrianZ, given my experience, I'm not clear of the need for the manual bleed screw either. I suppose as another system high spot that area could trap air under some circumstances. The Alde operating manual also suggests it is not necessary, but goes on to describe a manual bleeding process that can be employed in cases of a "persistent" air lock.

Also, my convectors are connected as shown in @ChanW's diagram. I'm not sure why yours is different, but practically speaking I doubt it makes any difference in the operation of the system. 

During my flush and fill of my 2019 400 I found that the manual bleeding screw in the bath was helpful and small amounts of air were released 2-3 times during my fill that the auto bleeder did not seem to remove. That screw is higher than the rest of the loop except the reservoir itself.

Horigan

ScottG said:

@Tabaz, congrats on getting the glycol changed.

Can you (or others who have done this) elaborate a bit more on your experience refilling the empty system by just pouring glycol into the expansion tank?  Did the glycol mostly trickle in and fill the system with gravity, or did it need to be coaxed in by cycling  the circulator pump?

I'm not convinced this is easier than pumping the fluid in with the adapters (which took me only about five minutes with an empty system), but I can see the advantage for someone who just doesn't want to deal with acquiring or making any additional tools (pumps, adapters, etc.).

Draining, blowing, or vacuuming out the old glycol and then refilling in this manner would be a reasonable alternative for getting the job done.   

On my 2019 400 the system would not fully fill with gravity alone.  I would fill the tank and open the bleed screw to fill the system as much as possible, close the bleed screw, turn on the Alde for 10-15 seconds as the tank almost drained then turn off the Alde, fill the tank, and repeat briefly turning on the Alde and filling the tank about two more times.  This was with the pump(s) set on high (5).

ChanW

@Horigan, @qhumberd, it sounds like the manual bleed screw is in more sensible place on the 400 than on the 320. 

On the 320 it's at about the same elevation (actually a bit lower) as the reservoir tank, and just at the other end of the rear convector from the tank. It's a high point only if the tongue is down.

Tabaz

I simply put a large funnel in the expansion tank and used a clean water pitcher.  Poured the new fluid in and stopped when it reached the MAX level on the tank.  Waited a few minutes for the level to drop in the tank, then added more up to the MAX level.  Kept doing this until the level stopped dropping.  At the start of this process, I did open the manual bleed valve thinking it would speed things along, but it didn't, so I closed it.  Once the fluid stabilized at the MAX level, I followed Scott's instructions and turned on the pump on high (without propane or electric heat).  Had to add a few more pitchers of fluid as the air was purged from the system.  After about 10 minutes, the fluid level stabilized near the MAX level indicator.  Key here is to only add fluid up to the MAX level indicator in the tank.  This way you avoid overfilling the circuit.  VERY EASY process.  Mine took a little longer because of my "Basement" Alde circuit for winter camping.

Tabaz

BTW, my Alde circuit was completely dry (empty) before beginning the refill.

BrianZ

Agree, @Tabaz, only add fluid to the max mark.  I did that when refilling ours, and with the pump speed turned only about halfway up, the tank burped once or twice briefly and then the level dropped close to the min mark.

ScottG

I'll add that detail to the next update of the DIY instructions. It's not a big deal to remove a little if you overfill (as I did in my unbridled enthusiasm) but it's an extra step that can be easily avoided if you only fill to the max line.

BrianZ

My Alde Glycol 3-Way Flush Valve Mod:
I think I've been working on this, off & on, for more than a week (or is it a month? ), but I've finally finished; with plenty of help & advice gleaned from others, to whom I say "Thank you very much!" to all contributors & especially to @ScottG for getting things started & keeping them moving. 

I fully expect that having this extra bottom fill port will be worth the effort; as the next time I change the glycol (assuming same type), then I would only need to attach the glycol hose to the new port, flip the valve, open the drain, and push out the old stuff with the new until it reaches the tank.  After closing the drain & switching the valve in the opposite direction, I can then pump in from the bottom to fill the drain part of the hose & the expansion tank to the proper level without needing to access the tank to pour glycol.  It was very easy, even with the lines all empty.

Most of my time was spent dismantling T@B & glycol plumbing parts & then cleaning the corrosion from convector & coupler fittings - something I don't expect to have to repeat, due to extra steps taken to coat or cover exposed surfaces, as discussed under the corrosion topic.  See referenced topics & materials sources listed at the end.

I followed @ScottG's approach to removing old fluid by draining & then starting at the upper Alde hose connections; with the exception that instead of blowing out the convector pipes with air, I wanted to go straight to rinsing with water, which I thought might be more efficient.  To avoid losing track of where I was in the whole process, I jotted down some simple notes with an overall plan that I could refer to, in case of "now where was I?" senior moments (thanks, @ChanW for letting me use your diagram)..

These 5G buckets barely fit, but are handy for fitting all the glycol, plus at least one full rinse and seals with a water-tight top for taking to recycling..

The bucket barely fit under the drain, up against my "Helman scissor jack".  I found that a 1.5" PVC pipe fit snug over the multi-drain outlet, which includes the glycol tank overflow drain.  I think only a few drops came out, due to air pressure changes.

This next adapter assembly I put together was a great help for doing the initial water flush of both Alde & the convector loop. (Thanks, @fstop32! ) I also plan to replace the brass pieces with a second aluminum hose coupler to keep just in case I should ever need to remove the 3-way valve, to take its place.  (Plus a pair of inexpensice hose-pinching clamps to facilitate the replacement).

The photo below shows how the adapter fits to the incoming water hose and Alde output hose..
Tip:  Since this outgoing hose is filled with glycol and is at a low point in the convector loop relative to the other end at the expansion tank, I was concerned about leakage upon disconnecting it (per @ScottG's warning).  To mitigate, before disconnecting, I grabbed the hose in both hands & squeezed as hard as I could a few times to pump some of the glycol into the tank & out the drain, as the check valve only allows it to go in that direction, and I could hear some fluid drain out.  So, only minor leakage into the pan placed underneath (a carryout food container), though I still tried to keep the end of the hose elevated while connecting the adapter valve for flushing & tipped the open bleeder assembly upwards while plugging.  After flushing, I plugged the hose with a barbed PVC plug & hose clip on until blowing out the line.
The new 3-way valve is mounted at lower right below the AC outlet, with 3/4" barbed stainless steel fittings enlarged with heat shrink tubing, but not yet connected.

Next, was using the adapter to connect directly to the Alde output for flushing (check valve/bleeder assembly removed temporarily)..

Below, the adapter was connected to the convector loop hose for flushing.  Note that the double angled garden hose valves allow easier positioning and, more importantly, provides two shut off valves for dis/connecting, to avoid spills..
(And did you know that a cork from a wine bottle fits perfectly into the check valve pipe?  Prevents drips.)

My intent below was to show my point of view when controlling the actual pumping.  The inline pump switch is on the seat at left (plugged into 12V socket at back corner cabinet), and brass valve at right needs to be opened & closed at same time whenever pump is turned on/off.  Valve on hose cannot be left open, or fluid may be siphoned to or from the jug.  This position also allows me to monitor the tank level for appropriate filling & to avoid overfilling.

Below is the 12V pump..
Like others have done, I replaced the flimsy battery clamps with the socket plug.  Yet another good use for heat shrink tubing.  The pump is only about 1.5" in diameter, so can fit into jugs with a large cap like the 2G one I saved from kitty litter.

It helped to stick a small flashlight in the corner on top of the glycol tank to light it up & easily see the level (except in this empty tank!    see last photo for a level) ..

Since I had this photo of the hoses going to convectors & tank, I thought I'd label them for reference..

Below was the system being flushed with distilled water..
I initially used 3Gs of tap water for rinsing, followed by 3Gs of distilled water, then air.  After all the corrosion cleanup & reassembly, I flushed again with 3Gs of distilled water, then blew out & refilled with glycol. 
One thing I never forgot from my quantitative analysis chemistry course in college was that 3 rinses of small volume is better at reducing contamination than one large volume rinse. While that may be true of the glassware we used, in this case it takes a large volume as well to hit all the surfaces & crevices.  

And after draining, being blown out with 15 lbs max of compressed air, under manual control with a trigger & being held to the opening of the tube connected to the 3-way valve..

Fresh glycol going in..  Blue arrow shows control valve; green arrow shows direction of flow into Alde through pump.  By rotating the blue valve handle to the opposite direction, the tube going up to the expansion tank can be filled.  I overfilled the convector loop with an extra pint or two, before closing the drain & filling the expansion tank.

Closer view of the 3-way valve in the normal operating position, with flow going straight through the valve, as indicated by red arrows on top of the valve.  I added the "off" arrow on the handle to indicate that whichever direction it's pointing, that pipe is disconnected & the other two are connected.

Below is an example of the hose-pinching pliers I got for use on either side of the above valve, in case I should ever need to remove it and insert the previously shown adapter assembly in its place..


When I did the final fill of the of the tank using the valve, I stopped it at the Max line.  Then, after returning the valve to the normal operating position, I turned on the Alde pump (by using the "Cont" setting instead of "Therm" on the pump settings menu) & increased the speed by turning the knob on the back of the pump at base of Alde (some pumps have a remote switch) to about midway for  less than a minute until it burped, then the level dropped to close to the Min line.  I may add more later.  Next I ran the Alde for a heat test by turning on the gas, turning on my Alde 12V kill switch & control panel, then increasing the thermostat 20 degrees above ambient temp for 45 mins.  It was plenty warm everywhere.

I still have 3/4 of a gallon of fresh glycol left over.  Will probably be testing what's in the system before long for pH, etc, to get a baseline.
The End!
We hope.

5-24-2021 Followup:
I used my pH meter & refractometer to check pH and specific gravity, after running the pump for a few minutes to ensure good mixing:
pH = 9.7
SpGr = 1.261
Propylene freezing protection = -26°C (= -15°F)
For comparison, a year ago in June, the 3-yr old fluid measured:
pH = 9.6
SpGr = 1.308
Propylene freezing protection = -32°C (= -26°F)
The Amazon listing for the Century TF1 glycol states "-20 Below", while the label shows "Haze Point -34°F".

So, the pH appears to be fine/normal, but I'm not quite sure what to make of the specific gravity measurement, but it would appear that I've either got some dilution effect from residual rinse water, or the glycol itself is more dilute (or the  old glycol had either lost water content or gained dissolved solids, which is possible with all the corrosion that was found).  Either way, the temperature protection is more than adequate, and the difference is only about 3.5%.
I did run calibration checks with a pH=6.86 buffer for the pH meter, and with distilled water in the refractometer to verify the zero line calibration. 

Here's an example view in my refractometer (using it outside on a sunny day, or in a well-lit room, makes it easy to use)..

Above is just a manufacturer image, not my results.  I use the scale at left for glycol & battery acid specific gravity & propylene scale for freeze protection, plus the bottom zero line for distilled water to verify calibration.  I'm a retired med tech/clinical lab manager, so have been familiar with the refractometer device for many years, which is the lab reference method for urine s.g. testing.

References:

3-Way Valve Parts & Pressure Testing:
https://tab-rv.vanillacommunity.com/discussion/2665/changing-out-the-alde-fluid/p19

Conformal Coating & Convector Cleanup

https://tab-rv.vanillacommunity.com/discussion/13226/corrosion-of-alde-convectors/p12

Heat Shrink tubing..

https://tab-rv.vanillacommunity.com/discussion/13226/corrosion-of-alde-convectors/p11

https://www.amazon.com/dp/B07FPKVMTW

Rear storage cabinet removal & convector connections..

https://tab-rv.vanillacommunity.com/discussion/13226/corrosion-of-alde-convectors/p10

Barbed Stainless Fittings for 3-Way Valve:
(Requires heat shrink tubing for good fit)
https://www.amazon.com/dp/B07N9YWSF2
OR:
Barbed Brass Fitting for 3-Way Valve:

https://www.amazon.com/dp/B07VJKLPR2

12V Pump:

https://www.amazon.com/dp/B01NAGVGN3

Plug for 12V Pump:

https://www.amazon.com/dp/B08XW5ZP19

Pair of 90°Garden Hose Adapters:

https://www.amazon.com/dp/B08QTVMFK1

Aluminum Hose Joiner:
https://www.amazon.com/dp/B01GQVDCOC