Changing out the Alde fluid.

Sharon_is_SAM · March 2021

@ScottG - I emailed him back in November of 2018:)

nhmike · March 2021

@gregndeb’s adaptors and process work slick for changing fluid

jimcenname · March 2021

Sharon_is_SAM said:

I have seen lower pH quoted in this thread, so, I would say aim for 9😊

I checked the pH on fresh century and it's between 9 and 10.

Image: https://us.v-cdn.net/5021717/uploads/editor/fc/6vfo7mgnfs2a.jpeg

Sharon_is_SAM · March 2021

Spencer quoted the glycol pH should be 9.5 - 10.5. Good to know a baseline @jimcenname!

ScottG · March 2021

I tested my TF-1 with a benchtop pH meter in Dec 2019 (mentioned somewhere back in this extensive discussion). I got pH 9.25 with the new stuff, and--interestingly--pH 9.6 with (then) five-year-old stuff in the system.

At least one other member reported a similar finding. Not sure what it means, if anything.

Sharon_is_SAM · March 2021

@ScottG - maybe through evaporation, the glycol became a tad more concentrated and the pH rose a touch. Or just normal variation/margin of error.

Radcat · March 2021

My unit is new, so I won't have to do this for awhile. When I do, I will build a simple manual handle pump system. The pump I have in mind is a Whale Gusher boat bilge pump. It have rebuilt these things, they work with a rubber diaphragm and they are simple and reliable. They will move air/water out of the bottom of a sailboat at about 17 gpm. I'll get a local hose/hydraulic shop to fab the lines. Fisheries Supply has the pump for about $64. I have a new one sitting in my garage and plan to play around to see what can be done.

Sharon_is_SAM · March 2021

@Radcat - I see an opportunity for making some money!

bergger · March 2021

Sign me up for one.

db_cooper · March 2021

On our 320 the low point with the trailer tipped forward would be under the passenger side bench near the door. Seems like it would be easy for the factory to put a fitting near that radiator that you could attach a hose and gravity drain out the door to a bucket. I'm going to investigate that possibility with a friend who's a bit handier than me. He's put quick disconnects on all types of motorsports equipment to flush and drain easier. Got to be a way.

Radcat · March 2021

My thoughts as well. I was tracing my T@b system today looking for a low point that, in conjunction with the boiler drain, could be used to gravity drain the whole system. Problem is, if you are under warranty and modify the system, I think you void the warranty. However, if that low point corresponds to a hose connection, that opens up other options.

ScottG · March 2021

I think the addition of a second low-point drain in the convector loops is another viable option for getting all the glycol out of the system.

@ChanW had a plan to add such a drain, but I'm not sure if he ever got around to actually doing it. @tybladesmith added a second drain as part of a "basement loop" he added to heat the underfloor tanks.

If you do attempt a complete (or even partial) drain and subsequent refill from the reservoir without a pump, just be careful not to engage the electric heating elements when you activate the Alde to circulate the new glycol. The electric elements are bathed in glycol within the Alde and can burn up if they are run before the unit is completely filled. (This was a tip from nuCamp's Austin Jones from earlier in this discussion). One of the advantages of pumping is that you should be able to refill the entire system with the Alde completely off.

ScottG · March 2021

@db_cooper, you were one of the early contributors to this discussion. IIRC, you have been doing partial drain-and-fills using a different glycol from the Century product. May I assume you haven't had any problems mixing the two?

I've been wondering about this with Alde's recent switch to a different recommended product accompanied by stern warnings not to mix with the Century TF-1 used previously.

ChanW · March 2021

(nope, I never got a round tooit)

That's a good point re: keeping the heating coils turned OFF, if there's any chance they aren't submerged in glycol.

Note that with the older analog control panel, it's easy to have the circulation pump operating with no heat on, by turning on the far right hand slider switch to the 'Room Heat' position, while having no heat source selected - ie: the slider for the propane and the slider for the electric are both in the off position.

If you listen carefully, you can hear that the pump is operating all the time in that case.

I'm sure there's an easy way to do it with the digital control panel as well, but I'll leave those details to someone who has that control.

ScottG said:

......
If you do attempt a complete (or even partial) drain and subsequent refill from the reservoir without a pump, just be careful not to engage the electric heating elements when you activate the Alde to circulate the new glycol. The electric elements are bathed in glycol within the Alde and can burn up if they are run before the unit is completely filled. (This was a tip from nuCamp's Austin Jones from earlier in this discussion). One of the advantages of pumping is that you should be able to refill the entire system with the Alde completely off.

ScottG · March 2021

Yeah, I know 'bout those round tooits, @ChanW. I was supposed to undertake this glycol change thing a year ago. :-/

Good info about the analog panel. I've wondered about that but never tried it. I wasn't sure if having the heat off would shut down everything.

There may be a way to accomplish the same thing with the digital panel, but I'm a dedicated slider guy so I can't say for sure.

FWIW, Austin's specific instructions were to unplug the Alde's 120V AC connection to ensure the heating elements would stay off.

Horigan · March 2021

ScottG said:

FWIW, Austin's specific instructions were to unplug the Alde's 120V AC connection to ensure the heating elements would stay off.

That's a great simple method to protect the heating elements. Thanks for sharing.

db_cooper · March 2021

@ScottG
That's right I've been doing partial fills using Sierra low tox - which is easier to find and is almost the same color as the Century. I'm out of it, and bought 2 gallons of Century now that the price has come back down on Amazon.

I'd like to do a complete refill this year. I checked the PH of the current stuff and it's around 9, so I'm not in a big hurry. I've never had a problem with the Alde, I think the Sierra is fine to use, and wouldn't hesitate if I had to do a refill on a trip for some reason.

Thanks for the tip about not turning on the electric coils, in the past I assumed that first switch had to be on. I've been turning the circ pump to 5 to help purge, and I've been lucky not to damage the heat coils I guess.

If I do get around to putting a drain under the bench, I'll post it here. Probably in a few months.

Tampakayaker · March 2021

I saw a brief mention in this post about using a shop vac to either blow or suck out the extra fluid after draining. Has anyone tried that method yet?

Or would it make more sense to blow the lines with the drain open?

I have 3 gallons of fluid in my shed ready to go.

Sharon_is_SAM · March 2021

@Tampakayaker - we need a guinea pig!

Horigan · March 2021

I just did mine this morning and tried the blow out method, but could not blow anything out of the lower line from the reservoir. It was blocked, even with the pumps running (Alde and Flow). I ended up only changing out a little over a gallon. I now have almost two gallons for next year I guess.

Maybe the Flow is preventing the blow out method from working. I recall someone here was able to change out three gallons by just blowing on both hoses to the reservoir.

I second nominating @Tampakayaker to try the suck out method! What could possibly go wrong?...

Tampakayaker · March 2021

Horigan said:

I just did mine this morning and tried the blow out method, but could not blow anything out of the lower line from the reservoir. It was blocked, even with the pumps running (Alde and Flow). I ended up only changing out a little over a gallon. I now have almost two gallons for next year I guess.

Maybe the Flow is preventing the blow out method from working. I recall someone here was able to change out three gallons by just blowing on both hoses to the reservoir.

I second nominating @Tampakayaker to try the suck out method! What could possibly go wrong?...

We have a humble 320, no fancy flow or ginormous 400 heating system!

I'm debating what I want to do.

The snazzy diesel submersible pump is nice, but then with purchasing the pump, fittings, hose, and trying to get 12 volts inside (I know I could get a plug...more $ and use the 12 volt outlet) seems to be a pain, plus fitting hoses and 2 buckets inside.

The video was impressive with the colors changing while emptying the old fluid, then water, then new fluids. Not sure why he didn't use the yellow bucket to catch the old fluid, would be able to see the changing colors better.

I could open the drain, let the fluid drain out of the reservoir then put the shop vac hose over the reservoir opening and blow.

I guess if I leave the drain open it wouldn't matter if I'm blowing in both hoses at the same time?

ScottG · March 2021

To blow the trapped glycol from the reservoir to the existing low-point drain would require you to push the fluid backward through the system. This idea was floated earlier in the this discussion (by @BrianZ, IIRC) but he abandoned the idea after finding there was some sort of check valve in the glycol loop that would prevent reverse flow.

Horigan · March 2021

Ahhh. A check valve makes sense. I'm fine with yearly partial fluid change.

Horigan · March 2021

Thinking on this further and understanding there's a check valve, I'm going to try the following procedure on my 400 next year to get all the fluid out.

Unplug 120VAC power from Alde
Close propane valve
Set circulation pump to Continuous at control panel
Turn off Alde at control panel
Remove cover from Alde reservoir
Remove top cover from bathroom Alde heater to access bleed screw
Drain glycol from drain at bottom of trailer. (Almost all the fluid should drain from reservoir)
Open bathroom bleed screw and drain about a half cup until you see no fluid in reservoir, then close.
Remove lower (left hose from reservoir and use shop vac to suck out remaining fluid (about two gallons)
Put plug back in on outer drain
Put left hose back on to reservoir
Fill system until it stops accepting more
Set Alde pump(s) to setting 5 at pump (including Flow pump if installed)
Turn on Alde and monitor reservoir. Turn off when reservoir is drained.
Refill reservoir and turn on Alde again. Repeat until system stops receiving fluid.
With pumps running open bleed valve in bathroom to bleed system.
Refill reservoir if required
Reset pump to Thermal on Alde control panel
Reset pumps back to original speed settings (2.5?)
Re-install reservoir cover
Plug in Alde 120VAC plug
Open propane valve

Tampakayaker · March 2021

@horigan, the video I watched that was linked in an earlier post showed the fluid being pumped into the left hose and the right hose going to the overflow/catch bucket.

If you sucked on the left, would that be going against said check valve?

Horigan · March 2021

Tampakayaker said:

@horigan, the video I watched that was linked in an earlier post showed the fluid being pumped into the left hose and the right hose going to the overflow/catch bucket.

If you sucked on the left, would that be going against said check valve?

On my 400 the left hose had a check valve that prevented blowing it out, so this is the outflow into the reservoir where suction would work. I'm wondering if my hoses are reversed on my reservoir since the right side inlet is a bit higher, which I would think should be where the outflow comes in, with the pump suction hose coming out of the lower (left) port. When I pulled the drain plug the reservoir drained from the higher right port, hence why I used the bleeder to drain it more so I could remove the left hose without making a mess.

Maybe I should amend my instructions to apply the shop vac to which ever house can't be blown into.

Tampakayaker · March 2021

Horigan said:

Tampakayaker said:

@horigan, the video I watched that was linked in an earlier post showed the fluid being pumped into the left hose and the right hose going to the overflow/catch bucket.

If you sucked on the left, would that be going against said check valve?

On my 400 the left hose had a check valve that prevented blowing it out, so this is the outflow into the reservoir where suction would work. I'm wondering if my hoses are reversed on my reservoir since the right side inlet is a bit higher, which I would think should be where the outflow comes in, with the pump suction hose coming out of the lower (left) port. When I pulled the drain plug the reservoir drained from the higher right port, hence why I used the bleeder to drain it more so I could remove the left hose without making a mess.

Maybe I should amend my instructions to apply the shop vac to which ever house can't be blown into.

Makes sense.

The video was a European caravan, and it wasn't even a T@B, so who knows how those are made.

ScottG · March 2021

I think the suction idea could work, provided you could generate enough force in the system to draw all the old fluid up and out through the reservoir inlet.

However, at first pass, it seems like the suction approach would require just as much (if not more) futzing with hoses, tubes adapters, etc. than the method of just pumping new fluid in upstream until all the old fluid is pushed out downstream.

Not that i am criticizing, as I have yet to actually try any method to get this job done. :-) I'm still waiting on a little more warm up before I get the T@B out and start addressing some of my long neglected maintenance tasks.

As I've said before in this lengthy discussion, there are likely multiple ways to get this job done. So long as you understand how the system is arranged and how the glycol flows through it, whatever you do that works is a good idea!

Horigan · March 2021

Agreed. It all depends on what you have on hand. I don't have a pump or any adapters, but I do have a shop vac and duct tape.

ScottG · March 2021

I hear ya', @Horigan. I'm looking forward to your report if you go ahead and give this a try!

Changing out the Alde fluid.

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