Difference between Caution State, Warning State & Error State

[SmarthomeBot]

Dear all,

1) Does anyone know what the difference is between following 3 states.

**

In my setup I have following 3 AC units:

Every now & then the system throws me following error and always & only on the same unit.

After 10 minutes (default polling time) the error gets cleared

I'm trying to understand why these error logs (UO-00 - low refrigerant) always show up on only one unit.

2) If the whole system is low on refrigerant, why no errors are showing on the other two devices?

I know it might not entirely related to this integration and something might be wrong with my equipment. A technician will come & check it next tuesday.

If anyone has the magic answer to the bold questions, you are my hero of the day.

Thank you!

Edit 1:

I already found one part of my answers in the API documention:

However it still doesn't explain what Caution State is and why the error still only occurs on one unit

[eupesco]

I have the same problem with U0-00 on only one unit. Did the technician find anything? Do your units have a problem with low refrigerant?

[SmarthomeBot]

The pos installer has postponed the repair under warranty and is being very dodgy. As soon as I have news I'll write an update.

I would sincerely recommend to have also your system checked.

[SmarthomeBot]

Update: the installer still didn't come, he will come now Friday to do a warranty swap of an indoor unit. I don't know whether it will change the error codes/caution state logs.

Other interesting input:

1. I was at a renewable energy business fair last week and spoke to some Daikin "super" vendors and technical people. They said if the UO-00 error was real, it would show up in the Onecta app and the complete system would stop working. Unfortunately the 2-3 people I spoke to were unaware of how the API works and how the Caution state works

2. At Homey they are also implementing the Daikin API and some other people have mentioned similar logs on brand new systems:

https://community.homey.app/t/app-pro-and-cloud-daikin-onecta/54088/563
https://community.homey.app/t/app-pro-and-cloud-daikin-onecta/54088/570

In Homey the caution state messages was sending notifications, so they kind of swept the messages under the rug by disabling them.

https://community.homey.app/t/app-pro-and-cloud-daikin-onecta/54088/586

I'll keep you posted when this lousy guy is coming and see whether I still continue receiving these errors.

In the meantime I have been heating my home without any issues, only those logs who keep popping up in home assistant.

[SmarthomeBot]

The installer came yesterday and replaced the indoor unit with a new one. He performed a nitrogen pressure leak test and vacuum pumped the system. Both operations were successful. However, he didn’t remove and weigh the coolant to check if the system had the correct amount. Instead, he assured me that the system heats and cools sufficiently. So for now, everything is up and running.

Regarding the "errors," the caution states are still appearing from time to time. Since this installer isn’t very thorough, I didn’t bother asking him to investigate further. Instead, I’ll follow the advice I got from the vendors at the fair. How? I’ll streamline the reporting from the Onecta app to Home Assistant. Only Warnings and Errors will be displayed, while I’ll disable the caution state entities so they don’t show up anymore. I don't really need to know when the system goes into this mode everytime and apparently it's more common than thought and it is nothing to worry about. In my opinion it's really quirky and if I don't seee the logs anymore, It will give me less anxiety.

If the system ever breaks down, I’ll call someone more qualified to fully empty and refill it with the correct factory coolant amount using proper equipment. The coolant is factory-sealed and clean, and removing it for weighing risks contamination. So for now, I’d rather deal with a possible suboptimal coolant level triggering a caution state than risk introducing contaminated coolant into the system by an installer who deemed not so professional.

In the meantime I asked the same question to the Daikin API developer team so see if they can clarify this situation.

I ask Johnny to keep this discussion open until we have a real answer from Daikin.

[SmarthomeBot]

@eupesco Are you by any chance using Demand Control? I was using Demand Control on 60% for a long time.A possible theory I have is that Demand Control is meddling with some sensors causing these short caution states while the system maintains up and running. The output temperature with Demand Control is significantly lower than when deactivated, plausibly making the system think that there's not enough refrigerant in the system. I'm trying to see whether this is the case by doing a new test.

I did a 1 hour "power" test with following use case and it didn't trigger any error:

1. Turn off Demand Control and turn off all indoor devices, wait 1 minute and turn off the breaker to completely turn off the system and to reset error codes.
2. Turn on breaker and wait 1 minute and force refresh the Daikin integration in Home Assistant so all errors are cleared from all devices.
3. Take your remote, set mode to Heat and crank it up to 30 degrees on all your units for 60 minutes. After 30 minutes or so turn on Powerful mode on all of them. If you have a thermometer, try to see whether the temperature reaches more than 40 degrees. I used a baby thermometer which has max 42 degrees, I don't have an IR thermometer unfortunately.

With this heavy testing I didn't have a single error log or Caution State on all devices after 1 hour! I'm going to keep Demand Control off for 24 hours on normal temperature & usual parameters to see if I don't get any errors.

At least now I know that the system is acting normally, these logs again prove not to be of any significant importance.

[SmarthomeBot]

@eupesco So I have noticed the following two things

1. No Caution states were triggered with Demand Control off but the consumption is higher is a lot higher.

2)The units which have to perform the least are showing error UO but only here & on the remote

No errors whatsoever on Onecta app and the systeem keeps working.

Still no answer from Daikin whatsoever.

[eupesco]

Thanks for the information.

Yes, I have the same behavior when demand control is disabled (so no caution state). I could see that the caution state is mostly triggered when the demand control is below 60%.
Sometimes it is triggered when an indoor unit has reached its target temperature and is turned off (with and without demand control).

My units also show U0-00 in HA (as well as on the remote), but at some point of time the error is reset. I have never seen an error message in Onecta app either.

[SmarthomeBot]

Well I guess some kind of paramater or programming which we do not know is triggering all these messages.
As much as those logs are quirky and annoying to see, if our systems are working, I wouldn't spend too much attention to this.
I sent a reminder to Daikin BE for this. I would invite you to also send an e-mail to your local Daikin branch, because now we are both speculating and we both spent a small fortune on their equipment. At least they can investigate & provide us an answer.

[SmarthomeBot]

Here are some answers from a technical guy from Daikin:

1. Difference between the states:

The caution and warning states indicate that a symptom of an issue has been detected, but it is not yet severe enough to put the unit into an error state. An actual error occurs when a certain number of symptoms have been registered within a specific timeframe.

The U0 error typically indicates low refrigerant but can also be caused by a malfunctioning expansion valve. Your installer should be able to assist you with the U0 error, even if they are not fully familiar with the differences between the states.

2. Why the states get triggered by Demand Control

Yes, it can be caused by the demand control. In all honesty i advice our clients against the use of it because indeed it creates problems of not reaching high enough capacity.

The fact that the capacity is lower due to higher compressor frequencies can trigger the U0 error. This error is triggered when the indoor unit is not heating up fast enough the room which can make the heat pump think it can be a lack of refrigerant. Lack of refrigerant also is a cause for lack of capacity.

So yeah, as suspected, Demand Control is meddling with things by nerfing the output, triggering caution states.
Regarding the U0 error, if it's not a real refrigerant shortage it could indicate a malfunctioning electronic expansion valve.

If the system works and Onecta does not show errors, rest assured then.

[eupesco]

Great - thanks for sharing this information!
To rule out low refrigerant or a malfunctioning expansion valve, we will have to wait for the summer.

Regarding the second answer, I have a doubt: "The fact that the capacity is lower due to higher compressor frequencies can trigger the U0 error."
This I don't understand this - the demand control mainly limits the compressor frequency, right? The rest of answer makes perfect sense.

[SmarthomeBot]

Tbh I don't know the exact reasoning, I'm not going to bother asking for more details. What I however would like to see is what other Daikin branches from other countries would provide as an answer to see if they all say the same thing or perhaps contradict each other. Would be interesting to see.