Question about bleeding an Alde 3010

JP2558

I've read many of the posts here about maintaining the Alde system in my Tab 320. The manual that came with my Tab states the following:

"BLEEDING THE SYSTEM
Depending on how the pipes have been fitted, air pockets
may form when the heating system is filled with glycol
fluid. A sign that there is air trapped in the heating system
is that the heat released into the pipes only extends
2-3 feet or so from the boiler, even though the circulation
pump is operating.

In newly filled heating systems, small air bubbles can
form in the expansion tank, creating a gurgling sound. If
the circulation pump is stopped for a few seconds, the
bubbles will usually disappear; however, if the problem

persists, bleed the heating system to remedy the problem.

Automatic Bleeding
All boilers sold in North America come with an automatic
air vent (see Figure 8), which will bleed the heating system
automatically. If you do not have an automatic air
vent, a bleeder screw is fitted to the outgoing pipe for
manual bleeding."

My question is why would I still hear the gurgling sound described above, if my Alde has automatic bleeding? There is no bleeder screw, so I cannot bleed it manually.

Sharon_is_SAM

Typically the gurgling is due to the bubbling in the glycol reservoir due to activity of the pump.  If the pump speed is beyond 2, the gurgling is more pronounced.

JP2558

@Sharon_is_SAM - Thank you. I plan to check the pump speed setting tomorrow.

Bayliss

@JP2558, I am not sure what you are doing as far as bleeding the Alde, but your question reminded me of a December 2019 post by @Michigan_Mike.  I copied it at the time for future reference, so I have included it below for your consideration.  @Sharon_is_SAM's post about the pump speed also brought Mike's post to mind.  I have highlighted the info that you may be interested in:

POST BY @Michigan_Mike:

"Here is some information and recommendations from Austin Jones at the nuCamp repair shop....  In a nutshell Austin recommends that owners have this task done professionally and via a certified repair person to eliminate damaging your unit and protecting your investment.  Don’t shoot the messenger.  😀👍🏻

Alde & myself recommend using the proprietary pump to pump the fluid out of the system while pumping new in much like a transmission flush. This alleviates the need for a time extensive bleeding prosses and a lot of frustration. If you do not have a pump it is almost impossible to get all of the old fluid out of the system by just draining it out of the low point drain through the floor leaving sediment & tired old fluid in the system. Once you are refilling the system it may help to turn the pump speed up to max for a bit to help push the air bubbles out quicker. The glycol can also be tested via PH paper to see the quality of the glycol as well if you are on the fence about changing it. Sometimes the glycol can last several years if it is not used much.

The biggest thing to watch is if you are bleeding the system, is to unplug the 110 plug, so that in the event of the system calling for heat on shore power it will not burn up the heating elements if there is not adequate fluid in the Alde.

Final thoughts. If you are questioning your capability, pay to have this service done by a professional. If you are doing the change without a pump, drain it the best you can, unplug the 110 line to the Alde to avoid the system kicking on & cooking the heating elements. Only use Century transfer glycol or Alde’s brand of glycol.

Thanks, 

Austin Jones"

JP2558

 @Bayliss - Very interesting post. Tomorrow I think I’ll try maxing the pump speed, and then turning on the heat. Our forecasted high tomorrow is in the low seventies. Thanks for your input.

Bayliss

Sounds good, @JP2558.  Be sure to turn the speed back down to "2" when you are done giving that a try, or you'll likely have the gurgling sound as @Sharon_is_SAM mentioned.

WOOPS!  There was more to that info from Austin.......I missed it when cutting and pasting.  Please see my earlier post for the full info provided by Austin at nuCamp (last two paragraphs of his message, which I have added to my earlier post.)  Sorry about that.  (Greg)

ScottG

I'm not sure the gurgling you are hearing necessarily reflects a need to bleed the system. The glycol loop is effectively open inside the reservoir tank so turbulent glycol flow (possibly from a too high pump speed) can cause some noise.

Also, there is (or at least was) a manual bleed valve near the passenger side of the rear heat convector. However, getting to it in newer units with the storage cubbies in the rear deck might be a challenge.

JP2558

Even though our unit is a 2018, the Alde has seen very little use. The overflow tank, when cold, shows glycol just above the minimum line. I may put a little bit more in there just for assurance. It's supposed to go down to 61 tonight so I may leave it (the Alde) on overnight to ensure it is heating properly, and to also see if the gurgling continues.

Denny16

You need to get the level,up,ha,way between the two marks.  If it is closer to the lower line, then add some more fluid to get the level up.  This will prevent sucking air into the system.
cheers