Changing out the Alde fluid.

ChanW

Wow! It's clear from that diagram that the 400 Alde with Flow is way more complex than our simple '360' setup.

@bayliss, here's a photo from the Alde catalog that confirms your suspicions.

ScottG

Good morning, fellow aspiring amateur Alde technicians! 

@Bayliss, et. al., there appears to be some variation regarding the non-return valve. On mine, it was a small piece incorporated into the "flow assembly" itself--I could feel it and (when the system was apart) see it right under the black zip ties just downstream from the air bleeder in this photo. 

 

It was clearly not the larger component BrianZ pictured on Page 6 of this discussion (though it presumably serves the same function):


The aluminum component under the metal spring clamps was just a hollow connector:



I'm thinking (guessing) that at some point the small integrated check valve I have was replaced with more robust version, at that in turn replaced the simple connector between the flow assembly and the hose to the first convector.

It's an academic discussion. Regardless of the specific configuration, the check/non-return valve on the 320 is located in the hose carrying glycol away from the boiler, just downstream from the automatic air bleeder. (In the 400, it appears to be at the outflow of the Alde Flow--same idea.)

If you think about the flow of glycol, this location is--technically--between the circulator pump and the first convector. However, describing it that way is unnecessarily misleading.

ScottG

pak said:

ScottG: how much pressure was required to fill the system. Did the back pressure, if any, pop the stopper out of the reservoir hole? 

@pak, filling did not take any undue force on the hand pump, even when the system was completely full. I expected to the adapters to pop out of the reservoir opening if I did not hold them firmly in place, but it turns out they stayed put on their own without any notable leakage.

I think it is important to remember this is not a pressurized system. The only resistance to moving fluid is that of the plumbing itself. If you go slow and steady and don't force things, there should be minimal issue with things popping apart.

ScottG

ReenieG said:

@ScottG thank you for the link and info!

You are welcome, @ReenieG--I agree a picture tells the story so much better.

After pondering it a bit, I'm sticking with my opinion that the circulator pump will not push air. I tried this--albeit accidentally--while I was changing my glycol...

As I mentioned previously, after pulling the plug and successfully draining only the reservoir, I was scratching my head as to why the boiler wasn't draining as well. In an attempt to shake things loose, I activated the circulator pump. Doing so did not help the boiler drain. It also did not push any more fluid into the reservoir at the other end (where it could exit though the open drain). Maybe if I had tried longer and with a higher pump speed I might have had some success, but wasn't my priority at the moment so I moved on to a more successful approach.

ScottG

The more I think about it, I think the purpose of those black zip ties is to help hold the smaller (older?) check valve in place. I need to adjust mine, as they got moves during disassembly:



Originally, they looked more like @ChanW's 2014:



Notably, the zip ties are missing on @Bayliss' 2019:

 
Both aluminum connectors look different from mine as well. Not sure what is going on there...

Horigan

ChanW said:

I have a '320’...

With the shop-vac method, where do you suck?.... er, where do you put the "suction point" of the vacuum? (Ok, there's no way to say it so it sounds 'polite'...)

I sucked from the inlet port inside the tank, and it didn't get all the glycol, I drained two cups more from the drain tube. Still only about 1¾ gallons total.

Makes sense. Once the hose has an 'air path', the fluid will lie on the bottom of the hose and just sit there.

I taped the shop vac hose to the hose that feeds fluid INTO the reservoir.  This hose doesn't drain when you drain the system due to the check valve.  Access to this reservoir hose is much easier on a 400...   

Bayliss

@ChanW and @ScottG, thank you both for the further analysis of the location of the non-return valve on Alde systems without the Alde Flow.  I imagine you (and others on this forum) find it much easier to troubleshoot issues once you know how everything is constructed and the location/purpose of each component, so this entire discussion thread has been very informative.

tybladesmith

@ChanW, Could you be persuaded to do an amended elevation drawing of the heating system for a 320 S with the check valve and delete the left side convector? Nice work. What program did you use for that rendering?

Denny16

Regardless of the check valve’s specific location on different instructions, it is still somewhere near the boiler, between he Alde boiler after the circulation pump and before the first heat convector.  Having it incorporated in the auto Bleed valve, makes it harder to physically see it, but it’s there.
cheers

ScottG

Bayliss said:

@ChanW and @ScottG, thank you both for the further analysis of the location of the non-return valve on Alde systems without the Alde Flow.  I imagine you (and others on this forum) find it much easier to troubleshoot issues once you know how everything is constructed and the location/purpose of each component, so this entire discussion thread has been very informative.

You make a good point, @Bayliss --when you understand how something is assembled and how it works, it makes maintenance, modifications, and repairs a whole lot easier.

After changing my glycol and realizing how easy it was, I felt in hindsight this 400 comment discussion was a bad case of analysis paralysis. However, viewed from the opposite perspective, maybe all the analysis was exactly why it was so easy!  :-)

ChanW

@tybladesmith, I will, but that's not the system I have, so I can't really say how the hoses go! I imagine it might look like this below.

All I did was wander around in the Tab for a while and drew a map of where the hoses go. (the app I made it pretty with is "Affinity Designer", an inexpensive but capable Adobe clone for Mac)
------------------------------------------------------------------------------------------------
.)

ScottG

@ChanW, if you took the Alde glycol out line,  curved it up at the point of the arrow, and stuck it into the Alde on the same side as the pump (along with the air vent and check valve), you'd have a pretty good rendition of the post-2014 320 systems.

So many demands...  ;-)

ChanW

@ScottG! You're right! I'll get right on that.... 

Better yet, I'll have another glass of wine!

fstop32

I'm late to the game tonight and I think everyone has figured out where the check valve is but I'll throw my 2 cents in.  1st pic is my air separator & vent with the check valve just below it (to the left with the arrow).  2nd pic is looking back up the hose from the left end as seen in first pic.

Bayliss

Thanks @fstop32.  It is nice to get a look at it up close.  I appreciate the photos.

ScottG

Nice, @fstop32. That was what I mentioned seeing in my flow assembly when I had it off, but neglected to take a photo prior to reassembly.

Mine seemed like it was installed a little deeper, but I'm not 100% certain. The hose itself was soft except for a 1/4" or so solid section under the arrow sticker. It was definitely not the long aluminum fitting I pictured above, so Alde must have changed something post 2015.  

The end of the hose in your photo looks a little rough, like it might be cracked in several places. Am I seeing that correctly?

fstop32

@ScottG, I think the depth perception of the photo makes it look closer to the end of the hose but it's actually recessed in there an inch or two.  I think the cracking is superficial but I'm going to replace that assembly anyway, I just can't bring myself to reuse anything that might carry the cancer!  I'm even thinking of replacing the reservoir tank.

Denny16

You should be able to rinse the reservoir tank out with some warm water, than rinse with distilled water.  That should remove all traces of the old glycol, and any crystal deposits.
cheers

ScottG

@fstop, just be glad you have an older T@B. Rumor has it this is the next generation Alde 3030 that will be installed in the 2022 models.  ;-)

Tampakayaker

I see a nuke reactor and a flux capacitor in there....

ScottG

Yep. No propane required!

fstop32

This was the classified pic I got of the water management system...

ScottG

That's actually pretty cool looking! I'd love to have it in my T@B if there was enough room.  :-)

fstop32

I know!  I'd be proud to have that in my home mechanical closet!

ChanW

@ScottG, I'd like to see an elevation sketch of that please...

ScottG said:

@fstop, just be glad you have an older T@B. Rumor has it this is the next generation Alde 3030 that will be installed in the 2022 models.  ;-)

ScottG

FWIW, after completing my glycol exchange, I ran tests on the old original (2015) glycol and new glycol from a sealed container.

Appearance: No difference, both looked clear, bright yellow-green, with no evident debris or sediment.

Aroma: The new glycol smelled, well, faintly like antifreeze. The old glycol had an additional note of rubber, similar to that of the Alde glycol hoses.

Concentration/Freeze Protection: Measured with refractometer. Old: 46%/~-15F; New: 47%/~-17F

pH: Both looked about 9+ with litmus paper; tested to 9.7 with a benchtop pH meter.

Just for giggles, I also tested the new glycol in the system, once it had been thoroughly circulated. It's concentration/freeze protection was 45%/~-13F, and its pH (with meter) was 9.5.

Because I had flushed the system previously, I suspect the slightly lower values may have to do a bit of dilution from residual distilled water. I probably should have pushed a little more new glycol through when refilling, but I'm not losing any sleep over this miniscule difference.

To be clear, I'm not offering interpretations or conclusions, just information. By currently accepted standards, my six-year-glycol was virtually identical to the brand new stuff.

N7SHG_Ham

The unknown is the corrosion inhibitor package condition between old and new and depletion of that may be why the change interval is recommended. The ph and freeze point protection could be fine and it wouldn't tell whole story about suitability for continued use.

Heavy duty trucks have a Supplemental Coolant Additive or SCA that must be replenished over time, so instead of draining, the additive package is replaced assuming other qualities of the coolant are still OK.

Probably if there was a way to replenish the additive package in the Alde Glycol it would not require the frequent changes. Without being having someway to analyze the glycol it would be hard to know if the additive package is depleted.

ScottG

@N7SHG_Ham,  I agree 100%. However, to date those official (though limited) word from Alde and nuCamp has been that pH is your indicator of sustained corrosion protection. The current situation suggests that there may be other factors at play... 

fstop32

@N7SHG_Ham & @ScottG, I concur...but, in part my T@b got here because the "grasp", "generally regarded as sound practice" was to monitor the pH for signs of when to flush/refill (as @ScottG just mentioned).  It would appear now that while out of range pH would definitely be a call to action a "normal" pH cannot be assumed to mean there is no problem.
I've got more to say on this topic in general but I'm going to keep my powder dry for now 

db_cooper

@ScottG
Did you investigate the bulges at the convectors that you had noticed previously when you did your complete flush?

I've been doing the partial replace each year, and noticed I have hoses bulging a bit on the tank side of the rear convector.  Just did a partial replacement, but thinking about draining the tank and pulling those hoses.  Not sure I want to know, but everything else looks OK and heat working fine.