Changing out the Alde fluid.

Dalehelman · May 2021

@BrianZ
Thanks for the plug. I assume your adaptation is still working well for you.

BrianZ · May 2021

Yes, indeed it is!
They have been very handy. I continue to use them for routine wheel bearing lube.

ScottG · May 2021

Wow--nice work, @BrianZ. You took that idea way beyond anything I had envisioned. Backfilling the reservoir as the final step (thus eliminating the need to top up via the reservoir itself) makes good use of that multi-position t-port valve.

wolfeel2000 · May 2021

I got my fluid changed today. Thank you ScottG and everyone else who contributed to the pump method. I used Century Fluid since I had gotten 3 gallons two days before the recommended change. I will switch it out in two years. I only spilled a little bit.

Lessons learned:
a second set of hands would be nice
I'm a little large to try and squeeze into the space provided.

If anyone in the Seattle area needs the pump and adapters I am willing to loan mine to you.

Pintoplumber · May 2021

We have a 2016 CS S. I don’t know if the Alde fluid was changed before. We got it in 2019. A couple of months ago I gravity drained the boiler, I didn’t think to measure the quantity. Today I vacuumed the rest out. I used an old piece of rubber hose 5/8” inside diameter. Happened to be an old dishwasher drain hose. I put a small piece of 1/2” copper in the end to keep it centered in the expansion reservoir. I got a little more than a 1/2 gallon additional fluid. Really easy to do it that way. Will put the new Century fluid in this afternoon. The ph looked to be greater than 8.4 using the hot tub test strips.

Pintoplumber · May 2021

I added almost 1 3/4 gal. of Century fluid, but when I tried the Alde I had a blank screen. I had to replace the little glass fuse on the left. It burped once or twice that I could add more fluid. I’ll try running it again tomorrow.

Pintoplumber · May 2021

I ran the circulator a little this morning and it burped some air, so I added a little more fluid. I’m at a little over 1 3/4 gallons now.

pak · May 2021

Pintoplumber, that amount mirrors what I experienced in my '17 CS-S

sqrpeg · July 2021

Using a variation of the @Dalehelman shop-vac method, I was able to extract 7 quarts of old glycol from our 2018 320S.

Other reports I’ve found so far involve different models (CS-S) or vintages (2015). I know the layout is similar, but I was curious if anyone with a more recent 320S has successfully used the vacuum extraction method - and if so, how much glycol did you get out?

Ramon

lkc001 · July 2021

@sqrpeg what variation did you use on your method? Thanks!

sqrpeg · July 2021

I followed the same basic procedure, but instead of a spare vacuum wand I used a “1-1/4 in. x 12 in. White Plastic Slip-Joint Sink Drain Tailpiece Extension Tube”, cut down to 8” so it could more easily be maneuvered into position given the tight space. (Most stores also carry a 6” long version, but this can fall completely into the expansion tank and then is a PITA to fish out - ask me how I know this). The wider, threaded end fits loosely into the recessed bottom of the glycol expansion tank. To make a seal, I added a basin gasket I found at Ace Hardware, “Danco Rubber 1-3/8 inch D X 2 inch D Mack Basin Gasket”. The 1-3/8” ID fit tightly around the wider end of the extension tube, and the 2” OD seated well enough onto/into the bottom recess of the tank to provide a seal under vacuum. I left the threads on the end of the extension tube to prevent the gasket from being pulled down and off when removing the tube from the tank.

The narrow end of the extension tube fit into a short length of 1-1/4 ID clear vinyl tubing, and the other end of the vinyl tubing fit onto the shop vac hose (mine uses 1-1/4” attachments).

It still took a lot of contortions to get everything in place, but it worked OK.

After the initial rush of fluid, it kept coming up in dribs and drabs for quite a while so I just kept it running until it was down to just a few drops.

If/when I ever do this again, I would try adding a 90 deg elbow to the extension tube (or maybe just use PVC pipe instead) to make positioning easier and reduce the rise that the fluid has to travel.

To fill, I used a “Slippery Pete" hand pump which worked great. After 3 or so cycles of filling to the max line and burping with the circulation pump speed turned up, the gurgling stopped and I felt the system was full. It took a little over 7 quarts, which matched what I got out. I had three gallons of the Century fluid so I refilled with that - hopefully there will be more clarity on how and where to get the switch to Rhomar done properly when it’s time to change again.

Ramon

Dalehelman · July 2021

@sqrpeg
i love it when people add to an idea and make thing easier and better. I love to come up with ideas and see how others make them work.
Camp on

lkc001 · July 2021

@sqrpeg thanks so much for the great explanation & pics! I am going to attempt to do this myself near the end of my camping season this year. I'm so thankful for all the people on this forum like you and Dale Helman and others who help so much with DIY!

fstop32 · July 2021

In the FWIW "how much glycol does the system hold" department: As part of the corrosion fix I had removed the Alde boiler and all hoses and convectors were replaced so my entire system was dry before filling. I also chose to eliminate the small convectors in the driver side electrical compartment which were a part of the 2015 design. It took 2.5 gallons to fill it. I guess that's a good thing since I had to purchase the Rhomar in a 5 gal bucket, that leaves me enough to do it all again in two years 8^)

sqrpeg · July 2021

@fstop32 can you clarify if you still have a driver-side convector at all (or other significant layout changes that would increase volume) as part of your redesign/rebuild? I'm trying to reconcile your 2.5 gal capacity figure vs the 1.75 gal for my "stock" 2018 320S.

fstop32 · July 2021

@sqrpeg, originally my 2015 320 had two 8" convectors in the driver side bench cabinet. I did not replace them when I rebuilt as I didn't think the extra heat on the electronics was a good thing (met up with prev owner on a trip this week and he said he had to replace the WFCO power center once while he owned it).
Everything I put back in was as before, same size hose, convectors, reservoir tank, etc.. I hand pumped the new fluid in from the drain and didn't spill a drop and I've got half of the 5 gallon bucket left.
I'm thinking the difference might be that since I removed the boiler from the camper and had to flush all the old Century fluid from it before adding the Rhomar that in doing that I was able to completely empty the glycol chamber of any liquid. Additionally, since I was installing new hoses and convectors there was no possibility of leaving any glycol in the system. I wonder if sucking or blowing out a system as it sits in the camper leaves any glycol in the boiler or other points thus accounting for a lower volume drained from some systems?

fstop32 · July 2021

On a follow up note if one is replacing the glycol with the same product they had in their system then if some small amount of glycol is left in the system it would not be a problem. However, if one is changing to Rhomar then their system would definitely need to be flushed thoroughly with distilled water and/or the Rhomar Hydro-Solv to be confident there was no Century TF left behind.

sqrpeg · July 2021

Thanks for the info @fstop32 . I had bought into the notion that the shop vac method would evacuate all of the fluid from the system, in part because I reeeaaally wanted it to work. But if your 2.5 gal figure also applies to a stock 2018 320S configuration, then I really only got ~70% of the old glycol out, which would be a bummer.

Does anyone have concrete info on glycol capacity with the more recent 320S models? @BrianZ?

In hindsight, I should have at least opened the gravity drain to check if there was still any residual fluid left in the boiler and other driver-side plumbing before doing the refill. Regarding the hoses and convectors on the passenger-side of the system, I can’t think of a way to confirm with certainty that those are empty without actually disconnecting hoses.

I guess if you were going to flush with distilled water as the next step, then the color of the flush water would also give some indication of how much residual glycol, if any, was still present after the initial vacuum step.

What are others' thoughts on this?

ChanW · July 2021

@sqrpeg, I flushed twice with distilled water, and the second time I still had a wee bit of green tinge to it, but I'm not going to worry about it. If there was really 25% remaining, ie: (1.875/2.5)=.75, then I think that's 25%³ or 1.6% old glycol in the final solution, which I don't think is enough to matter.

The one thing I'll need to check is the final freeze protection I ended up with. If the glycol I put in there is good to -60°F, what's it good for at 25:75....

I'll check it with the refractometer one of these days.

(I'm sure a math-whiz is going to correct me on my numbers here... Rusty rusty 😬)

fstop32 · July 2021

@sqrpeg, one more side note I don't think I mentioned...the Alde boiler in my 2015 is the 3010 model. There might be a difference in glycol volume between the 3010 and the 3020 boilers.

sqrpeg · July 2021

@ChanW in my case, since I didn't do any flushes before refilling, a (potential) 7 vs 10 quart discrepancy would be more significant.

@fstop32 we also have the 3010 - our 320S was built a month or so before the switch to the 3020. I didn't think the boiler itself changed between models though.

Heading up to the mountains today, will revisit/reconnect when we get back.

ScottG · July 2021

If we're gonna' talk math...

The documented boiler capacity is 0.92 gallons. Approximately 33' feet of 22mm I.D. hose/convector (standard 320 without third convector) will hold another gallon. Maybe add another pint depending on how full your reservoir is, and the calculated system capacity should be right around two gallons.

Most (including me) have reported collecting a little under two gallons by various means of draining. I do suspect a little glycol remains trapped in the boiler body regardless of the method employed (gravity, pressure, or suction). So, @sqrpeg, I don't think your experience is abnormal.

I'm not sure why @fstop32 saw a higher capacity but, as noted, that was an unusual situation involving full dismantling and some reconfiguration.

The bottom line is that I'm not sure it really matters. If you are changing fluid types than you are going to have to thoroughly flush the system anyway. If you are not changing fluid types, than a little residual glycol left in the system shouldn't make much difference. In fact, if you simply push the old fluid out by pumping new fluid in, there is no real reason to worry about thoroughly emptying the entire system.

trimtab · July 2021

^ sounds like when I used to change brake fluid...

ScottG · July 2021

trimtab said:

^ sounds like when I used to change brake fluid...

Yep. Same idea!

BrianZ · July 2021

@ScottG, I believe @fstop32's higher capacity was due to having a third set of convectors in the driver's side electrical compartment. More tubing, so greater volume.

ScottG · July 2021

BrianZ said:

@ScottG, I believe @fstop32's higher capacity was due to having a third set of convectors in the driver's side electrical compartment. More tubing, so greater volume.

If you read his previous posts, he discontinued the third convector when he reassembled everything.

BrianZ · July 2021

Thanks, @ScottG. You're right, I spoke before seeing his July 9th comments about the refilling after removing the convectors. It's hard to say whether the discrepancy between his 2.5G versus other's 2G or less is due to lack of residual liquid or something else.
On our 2018 320S, I drained, then flushed with 3Gs of tap water, then 3Gs of distilled water, then blew out with air before installing my 3-way fill valve. Then I started filling with 3Gs of new glycol and overfilled by maybe as much as a quart, then refilled the drain tube & expansion tank. I ended up with a half gallon left, so I'm guessing I added at least 2G, maybe even as much as 2.25G, but it's hard to say for sure. When I was overfilling, the excess went down the drain, so wasn't measured. Once before I had calculated the system volume based on estimates of pipe length plus Alde's stated .92G internal volume and came up with right around 2G.

gophergrad · July 2021

Has anyone found a dealer in the Montana/Washington area that can do this for a reasonable price? My dealer doesn't seem to have any idea what I'm talking about. My old busted veteran self isn't really up for crawling upside down into any cabinets....

Freespirit · August 2021

@ScottG, and others. I have been following this thread from the beginning and find it very informative and helpful. I will be draining my Alde system in about 4 months and plan on using one of the two methods (pump or vacuum)discussed here. I will report my results.

I came across the attached video, 4th video of 4(maybe old news) but found it interesting and perhaps another alternative for the more adventurous DIY.

Chose not to include videos 1-3 in the interest of viewing time, but are very informative and well done.

https://youtu.be/UIg0fYVJmbQ

Cheers

ScottG · August 2021

@Freespirit, I've seen that video series. I don't think it was discussed here at any length, but the general idea of adding a second low point drain at the side convector has come up a few times. It's a good idea that would greatly simplify the draining process if it is a mod an owner is willing and able to undertake. That's a big if--once you start talking about cutting hoses and drilling holes I suspect many will tap out.

If I did this mod (and I may yet) I would probably avoid copper fittings as there is some concern about incompatibility with aluminum. Whether such a small amount of copper would make a difference I don't know.

Regardless of the method used to drain the system (if you even bother draining it all--not absolutely necessary if you use a pump to flush and fill) I still think filling with a pump is easier than trying to dribble glycol into the expansion tank a little at a time. Of course, that's easy for me to say, since I already built the pump. ;-)

I'm looking forward to your report of whatever method you employ!

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