2021 (Nov 2020) T@B 320 boondock error message: overheat red fail

PTom

Before leaving tomorrow (6/28) for Garner State Park we tried a/c in our 2021 T@B 320 boondock  for first time. We have two screens we can touch. We tried to cool the camper by lowering the temperature on Alde control.
When turned on, the top screen (above Alde) has been flashing (for several hours) OVERHEAT RED FAIL.  
For approximately 2 hours, it blew air that was not cold.
At one point, the unit quit blowing so we turned it off.
After 30 minutes off then back on, it started cooling but the top screen still has the error message.
We need to know correct way to turn on a/c so it works the first time we try it.
And, we need to know what the warning OVERHEAT RED FAIL means.
Pauline and Ron

pthomas745

The Alde provides heat and hot water.  Not air conditioning.  Not sure which air conditioner you have.

The overheat red fail message is a little cryptic.  This is what the manual says:

Overheat red fail: Overheat (red cable). Bleed the system of air. Check the fluid level in the expansion tank. It should be approx. 0.5 in (1 cm) above the Min mark when cool. Check that the circulation pump is responding. Wait 15 min for the fluid to cool down. This fault can arise if the heating system is run at high power at the same time as there are air pockets in the heating system; the heating system should then be vented properly. If the fault recurs, contact a dealer.

Before going through all this, you can try to reset the Alde to see if it will clear the message. 

The easiest way:  turn everything off.  Turn off the battery cutoff switch, located in the front of the trailer near the battery.  Wait a few minutes.  Turn the switch back on, turn the Alde back on, and see if the message has cleared.

This thread discusses the simple reset procedure above, and also shows where the 12V power cable is in the Alde unit.  Easy to find, but you just have to dig into the Alde a bit: https://tab-rv.vanillacommunity.com/discussion/11818/alde-red-alert-warning-for-nucamp-tab-s-320-resolved

If this doesn't work, you need to start checking your Alde glycol system.  First step would be find the Alde glycol tank, and check the level.

Here is a thread that shows where all the expansion tanks are for Tabs of most years.

https://tab-rv.vanillacommunity.com/discussion/10140/alde-glycol-expansion-tank-locations-for-the-tab-320-clamshell-and-400-models

pthomas745

And, if you don't have one, at the link you can find the Alde manuals.  You need the Alde 3020 manual. https://www.alde.us/manuals-and-documents/

WayneW

As you said, there are 2 touchscreens. The top silver one (Alde 3020) is for heating and hot water. The bottom white one (AIR8) is for the air conditioning unit which is mounted under the passenger side cushions.

I found the manual to be poorly written. For example “Must be carefully read the operating instructions and the Safety Instructions in preference to start unit!”  Regardless, if you follow the operating instructions as best you can you should be able to get your AC working. 

The Alde Overheat Red Fail is a separate issue and I think @pthomas745 is pointing you in the right direction. 

Good luck!