Alde Not Heating Camper

System · May 2023

This discussion was created from comments split from: Changing out the Alde fluid..

Misssubaru · May 2023

I absolutely can not get the heat on in my 2021 Tab 320S boondock
it was working great and suddenly stopped. I checked the glycol level and it appeared low, so I added more just above minimum level.
still no heat. I check all fuse’s especially that glass one. All good. I boosted the Alde to reset the controls. No heat. I tried elevating the tongue up for 15 minutes then to the lowest position. No heat. I checked to see if my pump was working and with my stethoscope I was able to hear that it’s running. The glycol is warm in the reservoir and the black tubing to the brass air thing is very warm. I took off the passenger side wood and exposed the heating coils. I did not feel heat after waiting an hour. I’m waiting to hear back from Alde to see what they recommend. Could it be that there’s a Hugh air bubble? I’m so disappointed that this hasn’t resolved.
any recommendations from anyone?
thanks

Dalehelman · May 2023

Are you heating with gas or electric? If gas make sure you have plenty. Light the stove to check.

Grumpy_G · May 2023

I'm half deaf and I can hear the pump running without getting close to it so I wonder if the pump is locked up and your stethoscope is picking humming from the motor windings or somewhere else.

ScottG · May 2023

@Misssubaru, when the pump is running there should also some noticeable movement of the glycol in the reservoir. Do you see any evidence of that?

Tenacity · June 2023

I am having the same problem (as Misssubaru) on my 2020 320S Boondock: plenty of hot water, but no heater (it’s not heating the air in the room). There is no movement in the glycol tank (no bubbling noises).

Fuses are good, I’ve pulled the plugs on the unit under the bench, I’ve hit the reset, tilted the RV, ran the Alde3020 on “continuous” for awhile…no joy.

Still searching the forum, but if you’ve got any ideas, I’d love to hear them! Thanks!

Donna

pthomas745 · June 2023

No heat from the vents scattered around the trailer? Can't feel anything at the convector under the passenger side bench? Have you reached down and felt/listened to the pump running?

The Alde heats the trailer by heating glycol, and then distributing the glycol to the convectors. A sure sign of not having enough glycol in the system is heat not being distributed. So, let the system cool down and check your glycol expansion tank.

Bayliss · June 2023

@Tenacity and @Misssubaru, you may/likely have already done this, and it may not be the issue, but, just in case...........make sure that the Alde control/display panel is set to "Therm" (not "Continuous") and adjust your temperature to what you want it to be to heat the trailer.

If the temperature setting is currently set higher than the current temperature inside ambient temperature, then it won't kick on (i.e., start heating.) It will only start heating the cabin when the cabin's ambient temperature drops below the temperature you have set on the Alde control/display panel.

Also, if the temperature inside the trailer is higher than that set on the control/display panel while you are testing it (e.g., in the afternoon), you'll have to drop the temperature setting on the panel below the current cabin temperature to get the Alde to start heating the trailer during your test.

Tenacity · June 2023

Thanks, Bayliss. It's set on THERM, and I fully understand about ambient temperature, etc.

I've been living in the RV full-time for the past couple of years and this isn't the first time this has happened. In the past, I've been able to pull the plug under the bench or hit the reset button But none of those tricks are working.

Here's the thing: USUALLY you can hear the boiler kick on. It's subtle and very quiet, but there are a series of clicks and humming as the boiler becomes active. Then the glycol unit starts to "bubble". But I'm not hearing ANY of these noises.

The valve near the boiler is hot, and the water gets hot. (And my water range temp is set in the middle).

Currently plugged into shore power, but the issue began while I was boondocking, immediately after running low on glycol. I'm at a loss as to how to proceed.

Sharon_is_SAM · June 2023

If the glycol reservoir was empty or very low, it is possible you have entrained air, hence the lack of circulating heat. Air lock is my guess.

Tenacity · June 2023

Setting the thermostat to "continuous" for a few minutes would have cleared that, right? (I've tried that)

I've also tried tilting the RV one way and then the other.

(Also, I believe my model of RV has self-bleeding valves?)

Tenacity · June 2023

pthomas745 Yep - Checked all that. It was working fine until the glycol ran low. I've tried tilting, pulling the plugs under the bench, hitting the reset button...

bergger · June 2023

They all should have just one self bleeder. Its a large brass upright valve right at the Alde. All the other bleeder valves are manual. If your getting hot water but no heat then you have an air lock or the pump is not working.

Make sure you have enough glycol in the system by looking at the reservoir. If so then turn the pump to continuous. You should see movement in the glycol tank pretty much immediately. If no movement turn the pump off and check the pump speed on the actual pumps. There is a tiny red knob you can turn. I usually have to put my cell phone by it so I can actually see it! I think I have mine set to 2.5 or 3. Make sure it is not turned all the way down. Turn it up to max, I think that is 5, and turn it back on to continuous to see if you get movement in the tank. If not but the pump is running then I too suspect an air block. You'll want to check each convector to see which ones have bleeder valves. Sorry but I only know where they all are in a 2021 400. Once you find them open them with the pump running, I recommend doing this when the system is cold, keep them open until fluid comes out then close them. Try catching the fluid in a small cup if you can. You can also check the auto bleeder and make sure it is not locked up. I believe some people in older units have had that issue from the valve not being vertical??

If you turn the pump on and can't hear it running at all then the pump is probably bad.

The self bleeder valve is the round brass thing at the top of the photo. Search on the forum for issues with this. I think some people had to lightly tap it with a wrench to get unlocked??

Image: https://us.v-cdn.net/5021717/uploads/editor/vs/2efh08qwzeh5.jpg

Here is a convector with a manual bleeder valve. Simply turn the knob on top to open and close it.

Image: https://us.v-cdn.net/5021717/uploads/editor/gg/04qzdea62gof.jpg

Tenacity · June 2023

bergger Mine looks a little different. I do see the brass thing, but nowhere do I see any type of bleed valve, or anything to "unscrew". It's solid.

Here's a question: Should there be glycol in that clear tube?
I do see SOME glycol in the tube, but I also see AIR.
Is this normal? or is this my problem?

Tenacity · June 2023

Also, the 320 Tab is different from the 400. I don't have access to the "fins". I know where they are, but they are not accessible.

And from what I've read, there aren't any bleed valves on the 320. (Please correct me if I'm wrong!)

Bayliss · June 2023

@Tenacity, based on the info that you were "running low" on glycol, I'm thinking you may have air in the system, which may be preventing the glycol from circulating.

Again, just guessing, but maybe that is why you have hot water, yet feel no heat in the cabin. Although the glycol is heating the water tank, it is not circulating through the glycol lines and in turn not making it to the convectors (metal fins) to heat the camper interior. Essentially, that is what happens when you use the "boost" mode for the hot water, because the glycol stops circulating throughout the trailer for 30 minutes or so and focuses the heating of the glycol around the hot water tank.

The following discussion may help. It includes a description of how to resolve a "persistent air lock." The same information is in the Alde manual, so review that as well.

https://tab-rv.vanillacommunity.com/discussion/7797/automatic-bleeder-valve#latest

One thing you might try first is to temporarily change the Alde control panel circulation setting to "Cont" (Continuous) and then manually adjust the Circulation Pump setting to a higher number (4 or 5) and then run the Alde with those settings for about five minutes. That may get any air bubbles out of the glycol line. Before manually changing the Circulation Pump setting, make a note of what it is currently set at (should be around 1.5 to 2) so that you can return it to that setting. The easiest way to remembr the setting is to take a photograph of it. Also, when you are done, don't forget to return the setting on the Alde panel to "Therm."

Here's a discussion about the setting on the Circulation Pump:

https://tab-rv.vanillacommunity.com/discussion/6203/alde-circ-pump-setting/p2

If none of the above works, you may need to "bleed" the system to get air out of the glycol line. If you are not comfortable doing that, you can take it to a dealer that can service the Alde.

Here's a discussions about bleeding the system. But, again, review the Alde manual for details on how to bleed the system. You can also use the "Search" function at the top of each Forum page to find similar discussions using terms like "bleed," "bleeding," or "bleeding the Alde."

https://tab-rv.vanillacommunity.com/discussion/526/the-need-to-bleed/p1

The following discussion is also worth a read. It is a longer one, so get your popcorn ready. I suggest that you take the time to read all these discussions (along with the Alde manual) for helpful info on how the Alde operates.

https://tab-rv.vanillacommunity.com/discussion/12778/alde-3020-heat-only-from-bed-vents/p1

Good luck!

bergger · June 2023

Some of the valves have a bleeder tube, the valve is on the end of it. It’s hard to tell from your pic and again I’m not totally familiar with the 320 but that looks like it may just be a glycol drain tube that runs out the floor of the trailer. If so it should be empty.

Tenacity · June 2023

Thanks everybody! All roads lead to Bleeder Valves so it's time to find them.

Bayliss · June 2023

@Tenacity, I'm not sure if it has any connection to your "no heat" issue, but below is a link to another discussion that is worth reviewing. If for nothing else, then for general knowledge.

https://tab-rv.vanillacommunity.com/discussion/13423/alde-automatic-air-bleeder-valve-improper-installation#latest

Travelin3D · June 2023

@Tenacity, the manual bleeder valve in the 320 (at least in my 2020) is located way down in the cavity below the passenger side speaker. If you remove the opposite triangular panel - and have skinny arms - you may be able to reach down and feel the valve. Here’s a pic. I currently have the whole rear shelf lid and cubby temporarily removed so it’s easy to access.

Tenacity · June 2023

Yes! I found it! Thanks for the post!

VonAustria · November 8

Two questions: I live in central Kansas , where can I order/purchase the “green” version Alde fluid?

Q2: At what pressure/volume does the Alde system move the fluid through the system?
I took my 2022 Tab 320 Boondock to a dealer for its first fluid change. 4 hour drive back home and the system is not circulating any fluid(I suspect). The tubes exiting the Alde boiler are hot but 3 feet down the tube it is only warm.and cold everywhere else. I suspect a blockage somewhere in the system.
Any suggestions or similar experiences? I am not going to make another 8 hour round trip to give them another go at it.

Sharon_is_SAM · November 8

@VonAustria - it sounds like you have air in the glycol lines. I moved your post over to this thread that you will find helpful.

VonAustria · November 8

An air lock was my first thought, but if it isn’t circulating the air can’t escape. Here is what I plan to do so if it’s a waste of time then I’ll try something else.

I’ve read that the Alde system in my 2022 Tab 320 is just shy of 2 ½ gallons. The tech at the dealer used about 1 ⅔ gallons. I suspect the fluid input to the Alde unit may not have any fluid available at the input.

So I am planning to get a pump and another gallon of fluid and pump in through the system as if I were replacing the fluid to hopefully force the air that may be trapped.

The tech told me he had only performed the replacement procedure maybe 5 times but on other manufacturers RVs so now I have little confidence he filled the system properly, assuming there is an actual proper way to do it to eliminate the vast majority of the air.

So, the follow-up for this is where can I purchase more of the proper/recommended Alde fluid? The tech at the Nucamp dealer used the green Alde fluid.

Horigan · November 8

You can get the fluid at Amazon, but I would try the following first before getting another pump.

There should be a bleed valve in your system somewhere to help get the air out. Maybe a 320 owner will chime in. For bleeding you also turn up the pump to level 5 to maximize the flow, then when you're done move them back to 2.5. The system pressure is pretty low since it's vented to atmosphere at the reservoir.

https://www.amazon.com/Truma-Resistance-Components-Conditions-Eco-Friendly/dp/B0C7J6WBRP/ref=sr_1_1?crid=27F0JRR3K13TQ&dib=eyJ2IjoiMSJ9.-99MsmvIOTfmPRE7q2eYedv_sfE3R-TKjOge5ySETMhdO7xWoRsvB4cBT6KXIhfJZ9R98MXum_6TV_U09dVmIQdO7klf5_EwTIavCpjjcsdEGiLGm58F77nGJlOo6Xn1gpkEfLxyJlRMt6_J6E1L_ydJWxkfzxtm3lgL7eZNSIjnorrZ9E3BU-X-MEUAtdkq.7w7ILwhFzXaydfSxfHLrdkXZc3ijOfWvqF5d0wy2dco&dib_tag=se&keywords=truma+alde+glycol+premium+heat+transfer+fluid&qid=1762623183&sprefix=truma+flui%2Caps%2C185&sr=8-1

pthomas745 · November 8

What is the level of glycol in the expansion tank?

The easiest way to clear an "air bubble" (The Great White Whale of the Alde) is to simply find the pump settings on the Alde Tools menu, and turn the pump setting to "Continuous". This enables the pump to simply run without the Alde being on, and it will drive the glycol through the system, and any air in the lines will be removed by the air "burping" into the glycol tank, or, by the actions of the Auto Air Bleed Valve, that brass fitting right there at the top of the Alde. This "turn the pump to continuous" method is used by owners who do the glycol exchange, and rarely, if ever, is any issue encountered.

I would also expect that the tech either: did not run the pump on Continuous, or.....if they did, they did not return the pump setting to "Therm". To heat the trailer, the Alde pump needs to be activated by the thermostat. I would try running your Alde again, getting your hand or ears as close as you can to the pump, and seeing if the pump is actually running.

There can be other reasons the pump will not start, even if everything on the control panel is correct. The thermostat may not be reacting to the temperature you are asking for. Find a separate thermometer of some type and compare the temperature the Alde thinks it is inside the trailer to what it really is. There are ways to adjust the "offset" of the thermostat. Don't be afraid to crank the heat up until you get some action from the thermostat or the pump.

Last: do you know how the tech changed the glycol? Did they use the "pump in the expansion tank" method? Did they disconnect or inspect any of the hoses on the Alde? There is a check valve right next to the Auto Air Bleed Valve, and if the check valve was removed (for whatever reason) and replaced facing the wrong way, it would prevent any movement of glycol past the valve.

VonAustria · November 9

I know the pump is running. The tech performed the process at the expansion tank and I know he did not run the system any longer than a few minutes. I’m sure he didn’t check to see if it was heating properly. There was nothing done in the cabin. I was not aware I could run the pump continuously without heat. This makes the most sense before I do a bunch of unnecessary work and expense.

Thank you so much for your suggestion.

VonAustria · November 9

The pump I was referring to was the pump used to replace the fluid, not the Alde pump. I’ve ordered some fluid from Amazon. I don’t believe I can adjust the Alde pump speed. I’m going to try the suggestions offered and let the bleed valve do its thing.

pthomas745 · November 9

The circulation pump does have a little teeny "switch" to adjust the pump speed. Not only is it hard to see, it is way down along the side of the Alde, so it will take a bit of Tab Yoga to get to. Look over this thread and it explains the pump speed setting with some photos.

https://tab-rv.vanillacommunity.com/discussion/10338/circulation-pump-speed

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