[SOLVED] [Comfoair] add Filter Reset in binding

I have an request for the comfoair binding. Within the reverse engineered protocol description (http://www.see-solutions.de/sonstiges/Protokollbeschreibung_ComfoAir.pdf) there’s the possibility to reset the filter (which I used within my legacy smarthome.py installation).

I don’t find an item for this within the docu, so I’m wondering where to put the request. :wink: so I’m trying here:

Please add the filter reset functionality as described in the linked PDF (sorry, german only) on page 14:


This would be great to have! :+1:

@holger_hees - are you still in business with this binding? :wink:

currently I’m not actively developing it. But if someone else is willing to work on it I can provide help and informations. e.g. where you should implement it.

The implementation should be very easy. But currently I have no openhab development environment so it is hard for me to implement and test.

But as I said, it should be a 1-4 liner in a config class. Not more.

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you can add a configuration inside this class

similar to the command ACTIVATE. This should be enough.

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Hi @holger_hees!
You already included “filter_reset” in the binding in the first place! :wink:
I just replaced my filters and tried to dig a bit into the binding and found it already there! :wink:

Integrating Filter Reset is very easy:
This is my items

Number Lueftung_Filterreset	"Filter Reset"	<switch>	(gComfoair, UG_Technik)	{comfoair="filter_reset"}

Now, just send “1” to the item and the Filtercounter will be set to 0 again. easy! :wink:


How can binding docs be updated?


Needs an update for the table within item configuration:

  • ewt_temperatur = READ
  • ewt_temperatur_low = READ
  • ewt_temperatur_high = READ
  • ewt_speed = READ
  • ewt_mode = READ
  • bypass_mode = READ
  • filter_reset = WRITE | 1 - filterhours will be reset to 0
  • filter_error = READ
  • error_reset = WRITE | 1 - error messages will be reset

Hi @binderth, great that you found the filter reset as this is nowhere documented currently… :+1:

Minor correction for the EWT channel, maybe a typo on your side but the channel for the EWT temperatures must be


Just without the “e” at the end as with most of the other temperature channels in the comfoair binding.


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Dear all

sorry for asking dumb questions but what is this “EWT” stuff? The docu above mentions something like “Erdwärmetauscher” but I’m not aware of such a feature in my ComfoAir 350. Is this the “Enthalpietauscher”?

@bernd_d: would it be possible that you post your complete item config for the additional items that are not mentioned in the OH docu?

Thanks & best regards

@JohnnyX, EWT is an acronym for “Erdwärmetauscher” an geothermal heat exchanger. This is an extra unit, that can be bought separate. More info here: Zehnder Comfofond

Here is my definition of additional items I have in use besides the ones in the doc:

Number Lueftung_EWT_Temperatur_Hoch "EWT Temperatur hoch [%.1f °C]" <temperature_hot> (Lueftung) {comfoair="ewt_temperatur_high"}
Number Lueftung_EWT_Temperatur_Tief "EWT Temperatur tief [%.1f °C]" <temperature> (Lueftung) {comfoair="ewt_temperatur_low"}
Number Lueftung_EWT_Temperatur "EWT Temperatur [%.1f °C]" <temperature> (Lueftung, Temperaturen) {comfoair="ewt_temperatur"}
Number Lueftung_EWT_Speed "EWT Differenz Geschwindigkeit [%.1f ]" (Lueftung) {comfoair="ewt_speed"}
Number Lueftung_EWT       "Erdwärmetauscher [MAP(bypass_de.map):%s]" (Lueftung) {comfoair="ewt_mode"}

 Number Lueftung_Filterreset     "Filterlaufzeit reset"  <timer>      (Lueftung)      {comfoair="filter_reset"}

If you do not have the geothermal heat exchanger installed, you won’t get any meaningful values for these items, except
for “Filter reset” which is nice to reset the used filter time to 0.


Thanks @bernd_d, got it now :slight_smile: Was not aware of this “add-on” since I only use the air exchange module.

@all in this thread:
Is anyone of you using the ComfoAir enthalpy exchanger (Klick)?

If yes, I saw that the above mentioned docu contains also some values that could be read via RS232 but honestly I have no clue whether this provides any added value.

Enthalpie Sensor Temperatur (°C*)
Enthalpie Sensor Feuchtigkeit (%)
Enthalpie Koeffizient (%)
Enthalpie Timer (0..240 = 0..2880 Min) 

What is your opinion on that - is it worth to open a feature request for these values?

Thanks & regards

FYI: I added a feature request for (1) humidity and (2) pre-heating/frost protection.

If you’re still using Comfoair and are still control it by your PC, you may be interested in expended binding.comfoair: https://github.com/gieemek/ComfoAir_Binding_modified
I expanded the original binding.comfoair by Holger Hees and I added a lot of read and write commands to it, so you can control Comfoair in the same range as by CC Ease or by CC Luxe.
Examples are also included there.
Cheers, Grzegorz.


You could submit a PR for the binding and then it would be available for all…

Yes, I want to do it.

WOW! Thanks for that! Sure I’d like to see that available in Standard.
If I find some time, I can test your JAR - and get back here.

…perhaps we should open a new thread then? it’s WAY more than just filter reset! :wink:

great improvement!

Thanks Holger, I feel proud of your recognition.
I’m still impressed by your comfoair.binding - very clean and nice code, congratulations! I would like to be able to program in this way.

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@gieemek: Wow… this is impressive!

btw. do you have any plans for a pull request, to bring all your changes back to the main openhab git repository.

I would like to see your changes there to use it too :slight_smile:

I’ve done it:

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