H24S1DA (DualCool) gives CH03 error :(

[JochenV1976]

First of all: this is a really great project! It's really great to be able to use a room sensor as temp sensor, instead of the sensor from the unit itselfs.

This weekend I installed 6 of these PCB's. 5 are working very good.
Only the 6th is a problem 🙁

The problem is on a H24S1DA indoor unit. The first hour, everything works fine. But then, you only see received messages, untill you receive an 'CH03' error on the unit 🙁

I did try to do a reboot after 30 minutes, but still no luck.
I installed the same hardware on another unit (other type) and everything works fine.

Even if I just connect the hardware onto the unit (with the unit OFF), I still have that CH03-error after +/- 1 hour.
Anyone else got this working on a H24S1DA - H09S1D - H12S1D - H18S1D DUALCOOL Deluxe unit?

I noticed a topic in the issues-list, but didn't found an answer :(

I have the idea that the LG-controller blocks on a CC.00.00.00.00.09.00.08.00.29.00.08.5B-ish message. I guess that the LG-controller doesn't aswer this, and it gets into a loop. So if someone has a solution for this, that would be very good.

[JanM321]

I see you already found #114 but it's basically the same issue. For some reason the AC unit is stuck in a loop sending the same message over and over.

Are your other units the same model?

[JochenV1976]

Thank you Jan for your answer.

No, the other units aren't the same. The others are PC09/PC12 and PM07.

Last night I was thinking about buying a PREMTB001, and connect it to the H24.
FIrst a test with only the PREMTB, to see if any error will come up. If that works, I can try with the LG-controller as slave. Will it be possible to see the PREMTB answers at that moment? If so, we could see what the difference is.
You think this is a good idea?

[JanM321]

That's worth a try, to see if the PREMTB100 avoids this problem somehow. It looks like a bug in the firmware of some newer models, but I'm not sure if/how we could work around it.

[JochenV1976]

Today I received my PREMTB001, and installaed it right away.
I can start and stop the unit, change the temperature, so everything looks fine.

But after +/- 1 hour, the CH03 also appears on the unit :(

As LG confirmed me that the PREMTB001 is compatible with the H24S1DA, I opened a case. Now waiting their answer ...
I'll keep you informed.

[JanM321]

Huh, interesting. It's a problem with the AC unit then instead of my implementation of the protocol.

It doesn't surprise me a lot though because LG seems to be paying a lot more attention to their ThinQ WiFi modules these days.

[pavolholes]

Today I received my PREMTB001, and installaed it right away. I can start and stop the unit, change the temperature, so everything looks fine.

But after +/- 1 hour, the CH03 also appears on the unit :(

As LG confirmed me that the PREMTB001 is compatible with the H24S1DA, I opened a case. Now waiting their answer ... I'll keep you informed.

Thanks a lot! I put this project on side when summer ended since my AC units are used only in summer. But still I’m following on this and I’m currious if we can make this working. Thanks for investigating this further than I did! 🙏

[JochenV1976]

First I received a feedback from LG:

Dear,

Did you order the cable from us?
If yes, are there at least 10.8 volts on the black and red wire?
If not, check the cable, otherwise the circuit board is not functioning properly.
If a float pump is attached, please disconnect it electrically for a moment.

Where was the indoor device purchased?

Of course, I replied to them, with the correct info:

Hello,

The cable came with the PREMTB001.
I checked the voltage at the backside of the PREMTB, and it is 11,96V (of course with RED + and BLACK -).
There is no float pump, so can't disconnect it.

The indoor device (together with 5 others, and 2 outdoor devices) were purchased at xxxxx last June.

The reason I want to use the PREMTB is a better control. Since the unit takes it temperature in the unit itselfs, regulation is not really good.

Please see also ticket #0004429 and #0004056.

Kind regards,

And then I received their answer:

Dear,

If the power supply is fine, you should contact your point of sale regarding the problem.
Perhaps they delivered a controller with the wrong software, as that is also possible.

As you can see, this is not really helpfull :(
I will try to contact the seller, but I guess the answer will be that there is no other firmware for the PREM.

[apppie123]

I don't know if it is helpful, but LG apparently releases some software and source code online.

https://opensource.lge.com/product/list?page=&ctgr=014&subCtgr=019&keyword=premtb&schType=

[apppie123]

Did you connect it to the cable or directly in the connector on the board of the AC? I notice there is a fairly large ferrite bead on the small cable inside P09 units.

Do you have an oscilloscope? Perhaps there is noise or ringing going on?

[JochenV1976]

Just connected it to the external connector ...

[JochenV1976]

Wonder if someone already found a solution for this?

[apppie123]

There were some changes recently where some request that the heatpump doesn't always respond to were removed. Have you tried this change? I was hoping this might solve it. But haven't tested this yet.