Changing out the Alde fluid.

Tampakayaker

Horigan said:

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. 

I had purchased an accessory kit for my shop vac a while ago. It came with an adapter and a reduced size hose and nozzles to clean in tight spots.  I think one of the nozzles would fit over the Alde reservoir hose.

[Deleted User]

So if you read back through this thread you will see i recently did a gravity change on my 400. It holds about 3 gallons total and I got out about 1 1/2 gallons. I was able to put back in 1 1/4 gallons at the time.  I took what was left with me in the second jug on my first trip this past weekend so I could top it off after it had a chance to run over night.  I was surprised to find the overflow/holding tank up at the front was totally empty the next morning! Scared me at first thinking maybe I didn't put the bottom drain plug back in correctly but no evidence it had leaked out that I could tell. The hot water was right on point no issues there (in fact so hot I had to dial back the temp.  I didn't test the heating capability because it was an unseasonably warm weekend, so I went out today and turned on the heat but after about a 30 minute wait the registers were not hot for heating the camper.  The black glycol hoses were getting hot back in the Alde compartment, but the one feeding the shower register and the glycol hose under the stove and up front were all still cold.  Did I just not wait long enough for it to circulate or is there too much air in the line maybe preventing it from going far?  I took the little metal cap off the bleeder valve in the shower but no air came out.  Of course I topped off the holding tank before I tried the heat.  It took almost two red solo cups full to top it off.  

Any thoughts? 

Sharon_is_SAM

Turn up the Alde glycol pump to 5 for a while and see if you can get more air out.  Then try to heat the cabin again.

ScottG

@TabbyShack, this sounds like a persistent air lock. If turning up the pump for a bit doesn't encourage the automatic at bleeder to finish the job, page 13 of the Alde 3020 Operating Manual has some additional tips for getting all the air out.

[Deleted User]

Awesome thanks for the suggestions! I will let you knew how it goes. 

[Deleted User]

Maybe it would help if I take the cap off the holding tank to give the air an additional escape route?

ScottG

I don't think the holding tank is sealed. At least mine isn't--it even has an open overflow tube.

Hmmm, considering that the tube drains onto the floor, maybe its primary purpose is not for glycol overflow but rather airflow.  :-/

[Deleted User]

Ok i think this is doing the trick! Lots of gurgling. So we need to add to the list of how too's.... make sure to run the Alde pump on 5 until the gurgling stops. (Seems common sense after the fact! DUH!) Maybe it was mentioned and I missed it. I see I'm going to have to add more glycol too. The holding tank is just about drained again! Gosh I hope I didn't do damage with running it over the weekend with alot of air and not enough glycol!!! Thankfully I only used the hot water over the weekend and not the heat.  The hot water worked fine.

[Deleted User]

Wow, I've almost put in 2 gallons (total) of glycol now and I only got out about a gallon and a quarter so clearly there was air in the line all along from new just not enough to have a noticable impact on the flow throughout the camper.  Ok, the pump is no longer making loud air whooshing sounds and no more air bubbles at the holding tank. Just hearing the turbulence in the holding tank from the pump pressure.  Problem solved! I have no doubt the heat will circulate now! 

ScottG

Phew! I suspect you got the internal glycol jacket filled, but still had air trapped in the convector loops. Under those circumstances, running the heaters for HW should not have done any harm.

[Deleted User]

Phew is right!  Yes, I agree with your thinking. I was thinking (hoping) the same thing. Seems perfectly logical. Good thing it was pretty warm this past weekend and when I needed heat I just happened to choose the heat pump for my heat source. 

This also might explain why the water temp was way too hot.  The glycol was just sitting back there around the water giving it maximum heat. I dialed down the water temp on the knob, but I bet next time (with the glycol flowing properly) the water might be too cool on the changed dial setting. 

MadCityJack

This week, I had my Alde fluid refreshed by RV Specialized Services in Lyndon Station, Wisconsin.  The owner read this forum post and built a simple pump/flush system.  He drained the reservoir, pumped out the remaining fluid, ran 15 gal of distilled water through, pumped in over 3 gals of transfer fluid in, letting the initial transfer fluid run out to ensure minimal distilled water remaining.  Seems to be working fine...  

ScottG

Those of you following this discussion may want to check out the recent thread about corrosion of the Alde aluminum convectors. This seems to be occurring even when the glycol still looks good and tests within the proper pH range.

It's unclear if this suggests there is some other corrosion resistant component of the glycol that degrades with time, or if something else is afoot.

Denny16

No, the anti corrosion agent in the glycol has a limited shelf/run time life in a system like,the Alde.  I had a corrosion issue with the aluminum heat exchanger manifold on a boat engine, that I did not keep up on replacing the glycol annually, as the boat was not being used. I had to replace the entire manifold due to corrosion caused by the old glycol.  It is important to follow the maintenance cycle for units like the Alde.

pak

I wonder if just using gravity by repeatedly filling the reservoir until you drained 3 gallons from the system. I live a long distance from the dealer and don't have a pump. Some of the quoted glycol change out prices mentioned here are quite high. Seem as though the cost of a few gallons of glycol might be worth a try. Is there a flaw in this thought? Thanks, Pete

MadCityJack

pak said:

I wonder if just using gravity by repeatedly filling the reservoir until you drained 3 gallons from the system. I live a long distance from the dealer and don't have a pump. Some of the quoted glycol change out prices mentioned here are quite high. Seem as though the cost of a few gallons of glycol might be worth a try. Is there a flaw in this thought? Thanks, Pete

From what I have read here, the issue with the gravity approach is that you can't get it all, at most 1/3 to a bit more from a full system.  My understanding is that the glycol won't keep filling the reservoir unless it is filled up again.   I'm no expert and I hope I understand the issue correctly--if not in the exacting, engineer sense.  I handed the job over to an RV technician who used a pump (see above).  The apparatus was simple, he said, but getting to the appropriate drainage points was not.  He took out the lower back storage area to get access.   I'll never truly know the quality of the job that was done so I have to trust the integrity of the technician--which I do.  However, I have read that by doing an annual or more frequent reservoir drain and refill that the old glycol is gradually diluted with the new glycol and the attendant anti-corrosives are added to the mix.  It is argued that this is better than no change of the glycol.  That seems logical, but it really is an empirical question.  

Denny16

Yes, doing an annual partial drain, is better than none...
cheers

ScottG

The total capacity of a 320 system is probably closer to two gallons, and gravity draining will empty about 2/3 of that. So, yeah, certainly better than nothing.

@pak, if I understand your proposal correctly, I suppose it could work--in theory. You vacuum out the reservoir, refill it, circulate the glycol a bit to move the new stuff down and push some old stuff up, and repeat until you've removed three gallons. The practical problem is that you would never have a clear sense of how much new stuff you actually got in, and how much old stuff you got out. Ultimately there would still be a portion of both left in the system.

Tampakayaker

Wonder what would happen if after you do the gravity drain you hook up a shop vac to the bottom drain?  Would you suck the system clean, or would that pesky one way valve get in the way? And I'm talking about a 320 which seems to have a smaller and less complicated set of radiators and tubing.

ScottG

@Tampakayaker, my understanding is the pesky one-way valve would prevent you from drawing fluid back through the boiler and out the drain. Drawing it in the other direction won't work either as the vacuum would be broken at the reservoir tank.

Because of my potential corrosion issues I've been re-thinking my pending fluid change. In short, I'm going to try removing the short piece of hose connecting the upper and lower side-bench convectors. I believe this would create a low-point gravity drain that would empty most of the glycol trapped in the convector loop. I'll reserve further comment until I actually give this a try...

Tampakayaker

ScottG said:

@Tampakayaker, my understanding is the pesky one-way valve would prevent you from drawing fluid back through the boiler and out the drain. Drawing it in the other direction won't work either as the vacuum would be broken at the reservoir tank.

Because of my potential corrosion issues I've been re-thinking my pending fluid change. In short, I'm going to try removing the short piece of hose connecting the upper and lower side-bench convectors. I believe this would create a low-point gravity drain that would empty most of the glycol trapped in the convector loop. I'll reserve further comment until I actually give this a try...

Watching the videos of pumping fresh fluid thru the system it seems like there is an output line from the reservoir and a return line.

My reservoir is in the "headboard" area of my 320, so I think i can get to the lines fairly easy.  So after draining and resealing the drain plug what about a shop vac sucking on the return line to the reservoir.  Think that will pull out all the remaining fluid?

I'm not bothered by the cost of a submersible pump if that's the way to go, just by the the amount of peripheral equipment needed and the small space of the T@B to work in.

ScottG

I think sucking on the return line at the reservoir could work--at least in theory. It would really depend on how good a seal you have with the vac, and whether the vac could generate enough force to draw the remaining fluid up and out.

Tampakayaker

Mine is pretty strong.  It's a full sized one, not one of the minis.  It would be a pain squeezing it in the 320, but I think it would be simpler than the pump, buckets and hoses.

Wonder if I should try to pump distilled water thru, then drain and suck again to get all the old stuff out?

If the heat and hot water were off, would using the ALDE pump to circulate the distilled water hurt?

All these questions.  

ScottG

Good questions, though...

If you can get the circulator to run without activating a heat source, I don't think it would hurt anything. I suppose it's possible the circulator pump relies on the glycol for lubrication (and that water won't cut it). I highly doubt it, but I don't know for certain.

Tampakayaker

I'm thinking, with the draining, then trying to suck out the remaining, might not need to flush with distilled?

The video I watched from Great Britain didn't use distilled water, but the old and new fluids were different colors so he knew when the system was flushed and full.

Would have to measure what came out between the 2 methods I guess and see if most came out.

Like I said earlier the price of the pump isn't a deterrent, but having another specialty item that only gets used every couple of years hanging around and taking up space in my overcrowded shed is a pain.

Why couldn't they have the drain situated to get 99% of the old out!

ScottG

Unless there is a compelling reason to do a distilled water flush (glycol looks or tests bad, corrosion evident, changing glycol brand) it's not strictly necessary.

I wasn't planning to flush mine--just pump the new fluid in to force out what remains of the old. I might rethink that now, but only because of the corrosion issues that have recently surfaced.

Horigan

I tried the shop vac method and it worked great at getting all the fluid out.  After draining the system from the bottom of the trailer you need to drain a cup or so from the shower bleed valve to get all the fluid out of the reservoir so you to disconnect the lower hose and duct tape to the shop vac hose.

When refilling you need to monitor the reservoir and shut down the Alde when it empties (less than 10 seconds) then refill and power up the Alde.  Had to do this three times before the levels stablized.  Be sure to put the reservoir cap on tight when re-powering the Alde!

First pic is the shower bleed valve setup, next are a couple of pics of the shop vac set up, and finally the two gallons captured in the shop vac.  

I've updated my full procedures after the pictures.

1. Unplug 120VAC power from Alde
2. Close propane valve
3. Set circulation pump to Continuous at control panel
4. Turn off Alde at control panel
5. Remove cover from Alde reservoir
6. Remove top cover from bathroom Alde heater to access bleed screw
7. Drain glycol from drain at bottom of trailer.  (Almost all the fluid should drain from reservoir)
8. Open bathroom bleed screw and drain about a half cup until you see no fluid in reservoir, then close.
9. Remove lower (left hose from reservoir and use shop vac to suck out remaining fluid (about two gallons)
10. Put plug back in on outside drain
11. Put left hose back on to reservoir
12. Fill system until it stops accepting more
13. Set Alde pump(s) to setting 5 at pump (including Flow pump if installed)
14. Turn on Alde and monitor reservoir.  Turn off when reservoir is drained (about 5-10 sec).
15. Refill reservoir and turn on Alde again.  Repeat until system stops receiving fluid.
16. With pumps running open bleed valve in bathroom to bleed system.
17. Refill reservoir if required
18. Reset pump to Thermal on Alde control panel
19. Reset pumps back to original speed settings (2.5 for main, 1.5 for Flow)
20. Re-install reservoir cover
21. Plug in Alde 120VAC plug
22. Open propane valve

Tampakayaker

Sounds good.  Is the hose you disconnected from the tank the return line?

qhumberd

Horigan said:

I tried the shop vac method and it worked great at getting all the fluid out.  After draining the system from the bottom of the trailer you need to drain a cup or so from the shower bleed valve to get all the fluid out of the reservoir so you to disconnect the lower hose and duct tape to the shop vac hose.

When refilling you need to monitor the reservoir and shut down the Alde when it empties (less than 10 seconds) then refill and power up the Alde.  Had to do this three times before the levels stablized.  Be sure to put the reservoir cap on tight when re-powering the Alde!

First pic is the shower bleed valve setup, next are a couple of pics of the shop vac set up, and finally the two gallons captured in the shop vac.  

I've updated my full procedures after the pictures.

1. Unplug 120VAC power from Alde
2. Close propane valve
3. Set circulation pump to Continuous at control panel
4. Turn off Alde at control panel
5. Remove cover from Alde reservoir
6. Remove top cover from bathroom Alde heater to access bleed screw
7. Drain glycol from drain at bottom of trailer.  (Almost all the fluid should drain from reservoir)
8. Open bathroom bleed screw and drain about a half cup until you see no fluid in reservoir, then close.
9. Remove lower (left hose from reservoir and use shop vac to suck out remaining fluid (about two gallons)
10. Put plug back in on outside drain
11. Put left hose back on to reservoir
12. Fill system until it stops accepting more
13. Set Alde pump(s) to setting 5 at pump (including Flow pump if installed)
14. Turn on Alde and monitor reservoir.  Turn off when reservoir is drained (about 5-10 sec).
15. Refill reservoir and turn on Alde again.  Repeat until system stops receiving fluid.
16. With pumps running open bleed valve in bathroom to bleed system.
17. Refill reservoir if required
18. Reset pump to Thermal on Alde control panel
19. Reset pumps back to original speed settings (2.5 for main, 1.5 for Flow)
20. Re-install reservoir cover
21. Plug in Alde 120VAC plug
22. Open propane valve

This looks not that hard for the 2019 400 with the closet, so I am about to embark on a fluid flush and change in my T@B 400.

I was going to follow this procedure with one change. I plan to use this small submersible pump and connect to the reservoir hoses with a fitting and a couple  of connectors and hoses going to buckets.





I want to use  distilled water to pump thru the system first, ensuring it is all out when the fluid runs clear, then use the Century fluid and again watch for the color change. This may take some extra Century fluid but I feel a flush may remove more contaminants in the loop.

I want to make sure I pump in the direction the system usually flows, so is the lower hose that @Horigan shows above the return TO the Alde or is that hose coming FROM the Alde to the tank? I want to pump thru in the normal direction of flow to not be blocked by the one way valve. Is the flow rate on this pump too high compared to the Alde pump?

Any comments welcome and I will post my pics and procedure list IF this is successful. 

fstop32

I am so jealous at all the room you have to get to the reservoir in the 400!