Alde reservior overflow

TommyK

I was getting ready for a trip, flushed the system and put the water in camping mode.  The Alde system was off and when I turned on the water pump I noticed glycol running from the overflow tube.  When I bypassed the hat water tank it stopped.

mgreen2

Did you use antifreeze to winterize? I'd think that was antifreeze since glycol doesn't mix into with the plumbing system. Which overflow tube was it coming from?

TommyK

It was glycol and it was coming from the clear tube from the reservoir 

ScottG

As @mgreen2 noted, the domestic water and the Alde glycol are completely separate systems. Theoretically, the only way that running the pump could force glycol out of the reservoir is if there was a breach between the Alde's HW tank and glycol chamber. In such a case, water from the tank would be forced under pressure into the glycol system, forcing the glycol to overflow at the reservoir.

A similar question came up very recently in another discussion.

TommyK

I get it. What would be causing the glycol to leave the system and only when I’m filling the tank

Sharon_is_SAM

@TommyK - how full is the glycol reservoir?  I know you said the Alde was off, but a high Alde pump speed will cause churning and some potential overflow, or a backup into the reservoir can cause an overflow (large air leak into the glycol loops).  

What year and model TaB?  Nautilus?

Bayliss

Following up on @Sharon_is_SAM's post, the glycol reservoir level should only by about 1/2" above the "MIN" (minimum) mark.  If the tank is overfilled, I could see it exiting out the overflow tube, which is what it is for.

TommyK

The tab is 2020

Sharon_is_SAM

A 320?  The last photo below is helpful.  Where is the leak exiting?  

ScottG

TommyK said:

I get it. What would be causing the glycol to leave the system and only when I’m filling the tank

If the leak was between the water and glycol chambers inside the Alde, bypassing the Alde HW tank would remove the pressure that is forcing glycol out at the reservoir.

ScottG

Here is a schematic of the Alde core that may help explain what I was describing above.

TommyK

Is this a common problem 

Denny16

No, I have only heard of two issues like this caused by a leak in the boiler unit, and both were early models.
 Cheers 

ScottG

Agreed. the discussion I linked to above involved a 2021 400, but that problem never got confirmed. Prior to that, I don't recall any discussion here about failed boiler cores.

TommyK

Sharon it is coming from H. It is a clear tube

Sharon_is_SAM

@TommyK -
how did you confirm that it was glycol?  
Is it possible that the new onset pump pressure pushed some water out of the hot water tank overflow and you are seeing water exiting under the TaB from that large black exit port?  There are 3 drains that exit that black port.
The glycol reservoir overflow exits the top of the reservoir - can you expose the reservoir and observe for a rise in the glycol level to the overflow while the pump is running?  I would confirm this before assuming you have a breach of the Alde tank.

Denny16

Sam has a good point, and I agree, you should check to reservoir and watch what the glycol level is doing whilst the pump is working.
 Cheers 

TommyK

So I spoke with Adele and added to the reservoir. When I opened the valves to put everything in camping mode and turned on the water pump the glycol rose and went out the overflow. The pump on the Adle is set at 2 like they told me. Any suggestions 

Sharon_is_SAM

Sounds like you have a connection between the Alde water tank and the Alde glycol tank.  Contact a dealer.

You aren't alone: https://tab-rv.vanillacommunity.com/discussion/comment/186132#Comment_186132